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Diffstat (limited to 'gnu/gcc2/lib/stmt.c')
| -rw-r--r-- | gnu/gcc2/lib/stmt.c | 4749 |
1 files changed, 0 insertions, 4749 deletions
diff --git a/gnu/gcc2/lib/stmt.c b/gnu/gcc2/lib/stmt.c deleted file mode 100644 index 5647d26ce94a..000000000000 --- a/gnu/gcc2/lib/stmt.c +++ /dev/null @@ -1,4749 +0,0 @@ -/* Expands front end tree to back end RTL for GNU C-Compiler - Copyright (C) 1987, 1988, 1989, 1992 Free Software Foundation, Inc. - -This file is part of GNU CC. - -GNU CC is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2, or (at your option) -any later version. - -GNU CC is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -GNU General Public License for more details. - -You should have received a copy of the GNU General Public License -along with GNU CC; see the file COPYING. If not, write to -the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ - - -/* This file handles the generation of rtl code from tree structure - above the level of expressions, using subroutines in exp*.c and emit-rtl.c. - It also creates the rtl expressions for parameters and auto variables - and has full responsibility for allocating stack slots. - - The functions whose names start with `expand_' are called by the - parser to generate RTL instructions for various kinds of constructs. - - Some control and binding constructs require calling several such - functions at different times. For example, a simple if-then - is expanded by calling `expand_start_cond' (with the condition-expression - as argument) before parsing the then-clause and calling `expand_end_cond' - after parsing the then-clause. */ - -#include "config.h" - -#include <stdio.h> -#include <ctype.h> - -#include "rtl.h" -#include "tree.h" -#include "flags.h" -#include "function.h" -#include "insn-flags.h" -#include "insn-config.h" -#include "insn-codes.h" -#include "expr.h" -#include "hard-reg-set.h" -#include "obstack.h" -#include "loop.h" -#include "recog.h" - -#define obstack_chunk_alloc xmalloc -#define obstack_chunk_free free -struct obstack stmt_obstack; - -/* Filename and line number of last line-number note, - whether we actually emitted it or not. */ -char *emit_filename; -int emit_lineno; - -/* Nonzero if within a ({...}) grouping, in which case we must - always compute a value for each expr-stmt in case it is the last one. */ - -int expr_stmts_for_value; - -/* Each time we expand an expression-statement, - record the expr's type and its RTL value here. */ - -static tree last_expr_type; -static rtx last_expr_value; - -/* Each time we expand the end of a binding contour (in `expand_end_bindings') - and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here. - This is used by the `remember_end_note' function to record the endpoint - of each generated block in its associated BLOCK node. */ - -static rtx last_block_end_note; - -/* Number of binding contours started so far in this function. */ - -int block_start_count; - -/* Nonzero if function being compiled needs to - return the address of where it has put a structure value. */ - -extern int current_function_returns_pcc_struct; - -/* Label that will go on parm cleanup code, if any. - Jumping to this label runs cleanup code for parameters, if - such code must be run. Following this code is the logical return label. */ - -extern rtx cleanup_label; - -/* Label that will go on function epilogue. - Jumping to this label serves as a "return" instruction - on machines which require execution of the epilogue on all returns. */ - -extern rtx return_label; - -/* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs. - So we can mark them all live at the end of the function, if nonopt. */ -extern rtx save_expr_regs; - -/* Offset to end of allocated area of stack frame. - If stack grows down, this is the address of the last stack slot allocated. - If stack grows up, this is the address for the next slot. */ -extern int frame_offset; - -/* Label to jump back to for tail recursion, or 0 if we have - not yet needed one for this function. */ -extern rtx tail_recursion_label; - -/* Place after which to insert the tail_recursion_label if we need one. */ -extern rtx tail_recursion_reentry; - -/* Location at which to save the argument pointer if it will need to be - referenced. There are two cases where this is done: if nonlocal gotos - exist, or if vars whose is an offset from the argument pointer will be - needed by inner routines. */ - -extern rtx arg_pointer_save_area; - -/* Chain of all RTL_EXPRs that have insns in them. */ -extern tree rtl_expr_chain; - -#if 0 /* Turned off because 0 seems to work just as well. */ -/* Cleanup lists are required for binding levels regardless of whether - that binding level has cleanups or not. This node serves as the - cleanup list whenever an empty list is required. */ -static tree empty_cleanup_list; -#endif - -/* Functions and data structures for expanding case statements. */ - -/* Case label structure, used to hold info on labels within case - statements. We handle "range" labels; for a single-value label - as in C, the high and low limits are the same. - - A chain of case nodes is initially maintained via the RIGHT fields - in the nodes. Nodes with higher case values are later in the list. - - Switch statements can be output in one of two forms. A branch table - is used if there are more than a few labels and the labels are dense - within the range between the smallest and largest case value. If a - branch table is used, no further manipulations are done with the case - node chain. - - The alternative to the use of a branch table is to generate a series - of compare and jump insns. When that is done, we use the LEFT, RIGHT, - and PARENT fields to hold a binary tree. Initially the tree is - totally unbalanced, with everything on the right. We balance the tree - with nodes on the left having lower case values than the parent - and nodes on the right having higher values. We then output the tree - in order. */ - -struct case_node -{ - struct case_node *left; /* Left son in binary tree */ - struct case_node *right; /* Right son in binary tree; also node chain */ - struct case_node *parent; /* Parent of node in binary tree */ - tree low; /* Lowest index value for this label */ - tree high; /* Highest index value for this label */ - tree code_label; /* Label to jump to when node matches */ -}; - -typedef struct case_node case_node; -typedef struct case_node *case_node_ptr; - -/* These are used by estimate_case_costs and balance_case_nodes. */ - -/* This must be a signed type, and non-ANSI compilers lack signed char. */ -static short *cost_table; -static int use_cost_table; - -static int estimate_case_costs (); -static void balance_case_nodes (); -static void emit_case_nodes (); -static void group_case_nodes (); -static void emit_jump_if_reachable (); - -static int warn_if_unused_value (); -static void expand_goto_internal (); -static int expand_fixup (); -void fixup_gotos (); -void free_temp_slots (); -static void expand_cleanups (); -static void expand_null_return_1 (); -static int tail_recursion_args (); -static void do_jump_if_equal (); - -/* Stack of control and binding constructs we are currently inside. - - These constructs begin when you call `expand_start_WHATEVER' - and end when you call `expand_end_WHATEVER'. This stack records - info about how the construct began that tells the end-function - what to do. It also may provide information about the construct - to alter the behavior of other constructs within the body. - For example, they may affect the behavior of C `break' and `continue'. - - Each construct gets one `struct nesting' object. - All of these objects are chained through the `all' field. - `nesting_stack' points to the first object (innermost construct). - The position of an entry on `nesting_stack' is in its `depth' field. - - Each type of construct has its own individual stack. - For example, loops have `loop_stack'. Each object points to the - next object of the same type through the `next' field. - - Some constructs are visible to `break' exit-statements and others - are not. Which constructs are visible depends on the language. - Therefore, the data structure allows each construct to be visible - or not, according to the args given when the construct is started. - The construct is visible if the `exit_label' field is non-null. - In that case, the value should be a CODE_LABEL rtx. */ - -struct nesting -{ - struct nesting *all; - struct nesting *next; - int depth; - rtx exit_label; - union - { - /* For conds (if-then and if-then-else statements). */ - struct - { - /* Label for the end of the if construct. - There is none if EXITFLAG was not set - and no `else' has been seen yet. */ - rtx endif_label; - /* Label for the end of this alternative. - This may be the end of the if or the next else/elseif. */ - rtx next_label; - } cond; - /* For loops. */ - struct - { - /* Label at the top of the loop; place to loop back to. */ - rtx start_label; - /* Label at the end of the whole construct. */ - rtx end_label; - /* Label for `continue' statement to jump to; - this is in front of the stepper of the loop. */ - rtx continue_label; - } loop; - /* For variable binding contours. */ - struct - { - /* Sequence number of this binding contour within the function, - in order of entry. */ - int block_start_count; - /* Nonzero => value to restore stack to on exit. */ - rtx stack_level; - /* The NOTE that starts this contour. - Used by expand_goto to check whether the destination - is within each contour or not. */ - rtx first_insn; - /* Innermost containing binding contour that has a stack level. */ - struct nesting *innermost_stack_block; - /* List of cleanups to be run on exit from this contour. - This is a list of expressions to be evaluated. - The TREE_PURPOSE of each link is the ..._DECL node - which the cleanup pertains to. */ - tree cleanups; - /* List of cleanup-lists of blocks containing this block, - as they were at the locus where this block appears. - There is an element for each containing block, - ordered innermost containing block first. - The tail of this list can be 0 (was empty_cleanup_list), - if all remaining elements would be empty lists. - The element's TREE_VALUE is the cleanup-list of that block, - which may be null. */ - tree outer_cleanups; - /* Chain of labels defined inside this binding contour. - For contours that have stack levels or cleanups. */ - struct label_chain *label_chain; - /* Number of function calls seen, as of start of this block. */ - int function_call_count; - } block; - /* For switch (C) or case (Pascal) statements, - and also for dummies (see `expand_start_case_dummy'). */ - struct - { - /* The insn after which the case dispatch should finally - be emitted. Zero for a dummy. */ - rtx start; - /* A list of case labels, kept in ascending order by value - as the list is built. - During expand_end_case, this list may be rearranged into a - nearly balanced binary tree. */ - struct case_node *case_list; - /* Label to jump to if no case matches. */ - tree default_label; - /* The expression to be dispatched on. */ - tree index_expr; - /* Type that INDEX_EXPR should be converted to. */ - tree nominal_type; - /* Number of range exprs in case statement. */ - int num_ranges; - /* Name of this kind of statement, for warnings. */ - char *printname; - /* Nonzero if a case label has been seen in this case stmt. */ - char seenlabel; - } case_stmt; - /* For exception contours. */ - struct - { - /* List of exceptions raised. This is a TREE_LIST - of whatever you want. */ - tree raised; - /* List of exceptions caught. This is also a TREE_LIST - of whatever you want. As a special case, it has the - value `void_type_node' if it handles default exceptions. */ - tree handled; - - /* First insn of TRY block, in case resumptive model is needed. */ - rtx first_insn; - /* Label for the catch clauses. */ - rtx except_label; - /* Label for unhandled exceptions. */ - rtx unhandled_label; - /* Label at the end of whole construct. */ - rtx after_label; - /* Label which "escapes" the exception construct. - Like EXIT_LABEL for BREAK construct, but for exceptions. */ - rtx escape_label; - } except_stmt; - } data; -}; - -/* Chain of all pending binding contours. */ -struct nesting *block_stack; - -/* If any new stacks are added here, add them to POPSTACKS too. */ - -/* Chain of all pending binding contours that restore stack levels - or have cleanups. */ -struct nesting *stack_block_stack; - -/* Chain of all pending conditional statements. */ -struct nesting *cond_stack; - -/* Chain of all pending loops. */ -struct nesting *loop_stack; - -/* Chain of all pending case or switch statements. */ -struct nesting *case_stack; - -/* Chain of all pending exception contours. */ -struct nesting *except_stack; - -/* Separate chain including all of the above, - chained through the `all' field. */ -struct nesting *nesting_stack; - -/* Number of entries on nesting_stack now. */ -int nesting_depth; - -/* Allocate and return a new `struct nesting'. */ - -#define ALLOC_NESTING() \ - (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting)) - -/* Pop the nesting stack element by element until we pop off - the element which is at the top of STACK. - Update all the other stacks, popping off elements from them - as we pop them from nesting_stack. */ - -#define POPSTACK(STACK) \ -do { struct nesting *target = STACK; \ - struct nesting *this; \ - do { this = nesting_stack; \ - if (loop_stack == this) \ - loop_stack = loop_stack->next; \ - if (cond_stack == this) \ - cond_stack = cond_stack->next; \ - if (block_stack == this) \ - block_stack = block_stack->next; \ - if (stack_block_stack == this) \ - stack_block_stack = stack_block_stack->next; \ - if (case_stack == this) \ - case_stack = case_stack->next; \ - if (except_stack == this) \ - except_stack = except_stack->next; \ - nesting_depth = nesting_stack->depth - 1; \ - nesting_stack = this->all; \ - obstack_free (&stmt_obstack, this); } \ - while (this != target); } while (0) - -/* In some cases it is impossible to generate code for a forward goto - until the label definition is seen. This happens when it may be necessary - for the goto to reset the stack pointer: we don't yet know how to do that. - So expand_goto puts an entry on this fixup list. - Each time a binding contour that resets the stack is exited, - we check each fixup. - If the target label has now been defined, we can insert the proper code. */ - -struct goto_fixup -{ - /* Points to following fixup. */ - struct goto_fixup *next; - /* Points to the insn before the jump insn. - If more code must be inserted, it goes after this insn. */ - rtx before_jump; - /* The LABEL_DECL that this jump is jumping to, or 0 - for break, continue or return. */ - tree target; - /* The BLOCK for the place where this goto was found. */ - tree context; - /* The CODE_LABEL rtx that this is jumping to. */ - rtx target_rtl; - /* Number of binding contours started in current function - before the label reference. */ - int block_start_count; - /* The outermost stack level that should be restored for this jump. - Each time a binding contour that resets the stack is exited, - if the target label is *not* yet defined, this slot is updated. */ - rtx stack_level; - /* List of lists of cleanup expressions to be run by this goto. - There is one element for each block that this goto is within. - The tail of this list can be 0 (was empty_cleanup_list), - if all remaining elements would be empty. - The TREE_VALUE contains the cleanup list of that block as of the - time this goto was seen. - The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */ - tree cleanup_list_list; -}; - -static struct goto_fixup *goto_fixup_chain; - -/* Within any binding contour that must restore a stack level, - all labels are recorded with a chain of these structures. */ - -struct label_chain -{ - /* Points to following fixup. */ - struct label_chain *next; - tree label; -}; - -void -init_stmt () -{ - gcc_obstack_init (&stmt_obstack); -#if 0 - empty_cleanup_list = build_tree_list (NULL_TREE, NULL_TREE); -#endif -} - -void -init_stmt_for_function () -{ - /* We are not currently within any block, conditional, loop or case. */ - block_stack = 0; - loop_stack = 0; - case_stack = 0; - cond_stack = 0; - nesting_stack = 0; - nesting_depth = 0; - - block_start_count = 0; - - /* No gotos have been expanded yet. */ - goto_fixup_chain = 0; - - /* We are not processing a ({...}) grouping. */ - expr_stmts_for_value = 0; - last_expr_type = 0; -} - -void -save_stmt_status (p) - struct function *p; -{ - p->block_stack = block_stack; - p->stack_block_stack = stack_block_stack; - p->cond_stack = cond_stack; - p->loop_stack = loop_stack; - p->case_stack = case_stack; - p->nesting_stack = nesting_stack; - p->nesting_depth = nesting_depth; - p->block_start_count = block_start_count; - p->last_expr_type = last_expr_type; - p->last_expr_value = last_expr_value; - p->expr_stmts_for_value = expr_stmts_for_value; - p->emit_filename = emit_filename; - p->emit_lineno = emit_lineno; - p->goto_fixup_chain = goto_fixup_chain; -} - -void -restore_stmt_status (p) - struct function *p; -{ - block_stack = p->block_stack; - stack_block_stack = p->stack_block_stack; - cond_stack = p->cond_stack; - loop_stack = p->loop_stack; - case_stack = p->case_stack; - nesting_stack = p->nesting_stack; - nesting_depth = p->nesting_depth; - block_start_count = p->block_start_count; - last_expr_type = p->last_expr_type; - last_expr_value = p->last_expr_value; - expr_stmts_for_value = p->expr_stmts_for_value; - emit_filename = p->emit_filename; - emit_lineno = p->emit_lineno; - goto_fixup_chain = p->goto_fixup_chain; -} - -/* Emit a no-op instruction. */ - -void -emit_nop () -{ - rtx last_insn = get_last_insn (); - if (!optimize - && (GET_CODE (last_insn) == CODE_LABEL - || prev_real_insn (last_insn) == 0)) - emit_insn (gen_nop ()); -} - -/* Return the rtx-label that corresponds to a LABEL_DECL, - creating it if necessary. */ - -rtx -label_rtx (label) - tree label; -{ - if (TREE_CODE (label) != LABEL_DECL) - abort (); - - if (DECL_RTL (label)) - return DECL_RTL (label); - - return DECL_RTL (label) = gen_label_rtx (); -} - -/* Add an unconditional jump to LABEL as the next sequential instruction. */ - -void -emit_jump (label) - rtx label; -{ - do_pending_stack_adjust (); - emit_jump_insn (gen_jump (label)); - emit_barrier (); -} - -/* Emit code to jump to the address - specified by the pointer expression EXP. */ - -void -expand_computed_goto (exp) - tree exp; -{ - rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0); - emit_queue (); - emit_indirect_jump (x); -} - -/* Handle goto statements and the labels that they can go to. */ - -/* Specify the location in the RTL code of a label LABEL, - which is a LABEL_DECL tree node. - - This is used for the kind of label that the user can jump to with a - goto statement, and for alternatives of a switch or case statement. - RTL labels generated for loops and conditionals don't go through here; - they are generated directly at the RTL level, by other functions below. - - Note that this has nothing to do with defining label *names*. - Languages vary in how they do that and what that even means. */ - -void -expand_label (label) - tree label; -{ - struct label_chain *p; - - do_pending_stack_adjust (); - emit_label (label_rtx (label)); - if (DECL_NAME (label)) - LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label)); - - if (stack_block_stack != 0) - { - p = (struct label_chain *) oballoc (sizeof (struct label_chain)); - p->next = stack_block_stack->data.block.label_chain; - stack_block_stack->data.block.label_chain = p; - p->label = label; - } -} - -/* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos - from nested functions. */ - -void -declare_nonlocal_label (label) - tree label; -{ - nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels); - LABEL_PRESERVE_P (label_rtx (label)) = 1; - if (nonlocal_goto_handler_slot == 0) - { - nonlocal_goto_handler_slot - = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0); - emit_stack_save (SAVE_NONLOCAL, - &nonlocal_goto_stack_level, - PREV_INSN (tail_recursion_reentry)); - } -} - -/* Generate RTL code for a `goto' statement with target label LABEL. - LABEL should be a LABEL_DECL tree node that was or will later be - defined with `expand_label'. */ - -void -expand_goto (label) - tree label; -{ - /* Check for a nonlocal goto to a containing function. */ - tree context = decl_function_context (label); - if (context != 0 && context != current_function_decl) - { - struct function *p = find_function_data (context); - rtx label_ref = gen_rtx (LABEL_REF, Pmode, label_rtx (label)); - rtx temp; - - p->has_nonlocal_label = 1; - LABEL_REF_NONLOCAL_P (label_ref) = 1; - - /* Copy the rtl for the slots so that they won't be shared in - case the virtual stack vars register gets instantiated differently - in the parent than in the child. */ - -#if HAVE_nonlocal_goto - if (HAVE_nonlocal_goto) - emit_insn (gen_nonlocal_goto (lookup_static_chain (label), - copy_rtx (p->nonlocal_goto_handler_slot), - copy_rtx (p->nonlocal_goto_stack_level), - label_ref)); - else -#endif - { - rtx addr; - - /* Restore frame pointer for containing function. - This sets the actual hard register used for the frame pointer - to the location of the function's incoming static chain info. - The non-local goto handler will then adjust it to contain the - proper value and reload the argument pointer, if needed. */ - emit_move_insn (frame_pointer_rtx, lookup_static_chain (label)); - - /* We have now loaded the frame pointer hardware register with - the address of that corresponds to the start of the virtual - stack vars. So replace virtual_stack_vars_rtx in all - addresses we use with stack_pointer_rtx. */ - - /* Get addr of containing function's current nonlocal goto handler, - which will do any cleanups and then jump to the label. */ - addr = copy_rtx (p->nonlocal_goto_handler_slot); - temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx, - frame_pointer_rtx)); - - /* Restore the stack pointer. Note this uses fp just restored. */ - addr = p->nonlocal_goto_stack_level; - if (addr) - addr = replace_rtx (copy_rtx (addr), - virtual_stack_vars_rtx, frame_pointer_rtx); - - emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX); - - /* Put in the static chain register the nonlocal label address. */ - emit_move_insn (static_chain_rtx, label_ref); - /* USE of frame_pointer_rtx added for consistency; not clear if - really needed. */ - emit_insn (gen_rtx (USE, VOIDmode, frame_pointer_rtx)); - emit_insn (gen_rtx (USE, VOIDmode, stack_pointer_rtx)); - emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx)); - emit_indirect_jump (temp); - } - } - else - expand_goto_internal (label, label_rtx (label), NULL_RTX); -} - -/* Generate RTL code for a `goto' statement with target label BODY. - LABEL should be a LABEL_REF. - LAST_INSN, if non-0, is the rtx we should consider as the last - insn emitted (for the purposes of cleaning up a return). */ - -static void -expand_goto_internal (body, label, last_insn) - tree body; - rtx label; - rtx last_insn; -{ - struct nesting *block; - rtx stack_level = 0; - - if (GET_CODE (label) != CODE_LABEL) - abort (); - - /* If label has already been defined, we can tell now - whether and how we must alter the stack level. */ - - if (PREV_INSN (label) != 0) - { - /* Find the innermost pending block that contains the label. - (Check containment by comparing insn-uids.) - Then restore the outermost stack level within that block, - and do cleanups of all blocks contained in it. */ - for (block = block_stack; block; block = block->next) - { - if (INSN_UID (block->data.block.first_insn) < INSN_UID (label)) - break; - if (block->data.block.stack_level != 0) - stack_level = block->data.block.stack_level; - /* Execute the cleanups for blocks we are exiting. */ - if (block->data.block.cleanups != 0) - { - expand_cleanups (block->data.block.cleanups, NULL_TREE); - do_pending_stack_adjust (); - } - } - - if (stack_level) - { - /* Ensure stack adjust isn't done by emit_jump, as this would clobber - the stack pointer. This one should be deleted as dead by flow. */ - clear_pending_stack_adjust (); - do_pending_stack_adjust (); - emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX); - } - - if (body != 0 && DECL_TOO_LATE (body)) - error ("jump to `%s' invalidly jumps into binding contour", - IDENTIFIER_POINTER (DECL_NAME (body))); - } - /* Label not yet defined: may need to put this goto - on the fixup list. */ - else if (! expand_fixup (body, label, last_insn)) - { - /* No fixup needed. Record that the label is the target - of at least one goto that has no fixup. */ - if (body != 0) - TREE_ADDRESSABLE (body) = 1; - } - - emit_jump (label); -} - -/* Generate if necessary a fixup for a goto - whose target label in tree structure (if any) is TREE_LABEL - and whose target in rtl is RTL_LABEL. - - If LAST_INSN is nonzero, we pretend that the jump appears - after insn LAST_INSN instead of at the current point in the insn stream. - - The fixup will be used later to insert insns just before the goto. - Those insns will restore the stack level as appropriate for the - target label, and will (in the case of C++) also invoke any object - destructors which have to be invoked when we exit the scopes which - are exited by the goto. - - Value is nonzero if a fixup is made. */ - -static int -expand_fixup (tree_label, rtl_label, last_insn) - tree tree_label; - rtx rtl_label; - rtx last_insn; -{ - struct nesting *block, *end_block; - - /* See if we can recognize which block the label will be output in. - This is possible in some very common cases. - If we succeed, set END_BLOCK to that block. - Otherwise, set it to 0. */ - - if (cond_stack - && (rtl_label == cond_stack->data.cond.endif_label - || rtl_label == cond_stack->data.cond.next_label)) - end_block = cond_stack; - /* If we are in a loop, recognize certain labels which - are likely targets. This reduces the number of fixups - we need to create. */ - else if (loop_stack - && (rtl_label == loop_stack->data.loop.start_label - || rtl_label == loop_stack->data.loop.end_label - || rtl_label == loop_stack->data.loop.continue_label)) - end_block = loop_stack; - else - end_block = 0; - - /* Now set END_BLOCK to the binding level to which we will return. */ - - if (end_block) - { - struct nesting *next_block = end_block->all; - block = block_stack; - - /* First see if the END_BLOCK is inside the innermost binding level. - If so, then no cleanups or stack levels are relevant. */ - while (next_block && next_block != block) - next_block = next_block->all; - - if (next_block) - return 0; - - /* Otherwise, set END_BLOCK to the innermost binding level - which is outside the relevant control-structure nesting. */ - next_block = block_stack->next; - for (block = block_stack; block != end_block; block = block->all) - if (block == next_block) - next_block = next_block->next; - end_block = next_block; - } - - /* Does any containing block have a stack level or cleanups? - If not, no fixup is needed, and that is the normal case - (the only case, for standard C). */ - for (block = block_stack; block != end_block; block = block->next) - if (block->data.block.stack_level != 0 - || block->data.block.cleanups != 0) - break; - - if (block != end_block) - { - /* Ok, a fixup is needed. Add a fixup to the list of such. */ - struct goto_fixup *fixup - = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup)); - /* In case an old stack level is restored, make sure that comes - after any pending stack adjust. */ - /* ?? If the fixup isn't to come at the present position, - doing the stack adjust here isn't useful. Doing it with our - settings at that location isn't useful either. Let's hope - someone does it! */ - if (last_insn == 0) - do_pending_stack_adjust (); - fixup->target = tree_label; - fixup->target_rtl = rtl_label; - - /* Create a BLOCK node and a corresponding matched set of - NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at - this point. The notes will encapsulate any and all fixup - code which we might later insert at this point in the insn - stream. Also, the BLOCK node will be the parent (i.e. the - `SUPERBLOCK') of any other BLOCK nodes which we might create - later on when we are expanding the fixup code. */ - - { - register rtx original_before_jump - = last_insn ? last_insn : get_last_insn (); - - start_sequence (); - pushlevel (0); - fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG); - last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END); - fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */ - end_sequence (); - emit_insns_after (fixup->before_jump, original_before_jump); - } - - fixup->block_start_count = block_start_count; - fixup->stack_level = 0; - fixup->cleanup_list_list - = (((block->data.block.outer_cleanups -#if 0 - && block->data.block.outer_cleanups != empty_cleanup_list -#endif - ) - || block->data.block.cleanups) - ? tree_cons (NULL_TREE, block->data.block.cleanups, - block->data.block.outer_cleanups) - : 0); - fixup->next = goto_fixup_chain; - goto_fixup_chain = fixup; - } - - return block != 0; -} - -/* When exiting a binding contour, process all pending gotos requiring fixups. - THISBLOCK is the structure that describes the block being exited. - STACK_LEVEL is the rtx for the stack level to restore exiting this contour. - CLEANUP_LIST is a list of expressions to evaluate on exiting this contour. - FIRST_INSN is the insn that began this contour. - - Gotos that jump out of this contour must restore the - stack level and do the cleanups before actually jumping. - - DONT_JUMP_IN nonzero means report error there is a jump into this - contour from before the beginning of the contour. - This is also done if STACK_LEVEL is nonzero. */ - -void -fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in) - struct nesting *thisblock; - rtx stack_level; - tree cleanup_list; - rtx first_insn; - int dont_jump_in; -{ - register struct goto_fixup *f, *prev; - - /* F is the fixup we are considering; PREV is the previous one. */ - /* We run this loop in two passes so that cleanups of exited blocks - are run first, and blocks that are exited are marked so - afterwards. */ - - for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next) - { - /* Test for a fixup that is inactive because it is already handled. */ - if (f->before_jump == 0) - { - /* Delete inactive fixup from the chain, if that is easy to do. */ - if (prev != 0) - prev->next = f->next; - } - /* Has this fixup's target label been defined? - If so, we can finalize it. */ - else if (PREV_INSN (f->target_rtl) != 0) - { - register rtx cleanup_insns; - - /* Get the first non-label after the label - this goto jumps to. If that's before this scope begins, - we don't have a jump into the scope. */ - rtx after_label = f->target_rtl; - while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL) - after_label = NEXT_INSN (after_label); - - /* If this fixup jumped into this contour from before the beginning - of this contour, report an error. */ - /* ??? Bug: this does not detect jumping in through intermediate - blocks that have stack levels or cleanups. - It detects only a problem with the innermost block - around the label. */ - if (f->target != 0 - && (dont_jump_in || stack_level || cleanup_list) - /* If AFTER_LABEL is 0, it means the jump goes to the end - of the rtl, which means it jumps into this scope. */ - && (after_label == 0 - || INSN_UID (first_insn) < INSN_UID (after_label)) - && INSN_UID (first_insn) > INSN_UID (f->before_jump) - && ! DECL_REGISTER (f->target)) - { - error_with_decl (f->target, - "label `%s' used before containing binding contour"); - /* Prevent multiple errors for one label. */ - DECL_REGISTER (f->target) = 1; - } - - /* We will expand the cleanups into a sequence of their own and - then later on we will attach this new sequence to the insn - stream just ahead of the actual jump insn. */ - - start_sequence (); - - /* Temporarily restore the lexical context where we will - logically be inserting the fixup code. We do this for the - sake of getting the debugging information right. */ - - pushlevel (0); - set_block (f->context); - - /* Expand the cleanups for blocks this jump exits. */ - if (f->cleanup_list_list) - { - tree lists; - for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists)) - /* Marked elements correspond to blocks that have been closed. - Do their cleanups. */ - if (TREE_ADDRESSABLE (lists) - && TREE_VALUE (lists) != 0) - { - expand_cleanups (TREE_VALUE (lists), 0); - /* Pop any pushes done in the cleanups, - in case function is about to return. */ - do_pending_stack_adjust (); - } - } - - /* Restore stack level for the biggest contour that this - jump jumps out of. */ - if (f->stack_level) - emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump); - - /* Finish up the sequence containing the insns which implement the - necessary cleanups, and then attach that whole sequence to the - insn stream just ahead of the actual jump insn. Attaching it - at that point insures that any cleanups which are in fact - implicit C++ object destructions (which must be executed upon - leaving the block) appear (to the debugger) to be taking place - in an area of the generated code where the object(s) being - destructed are still "in scope". */ - - cleanup_insns = get_insns (); - poplevel (1, 0, 0); - - end_sequence (); - emit_insns_after (cleanup_insns, f->before_jump); - - - f->before_jump = 0; - } - } - - /* Mark the cleanups of exited blocks so that they are executed - by the code above. */ - for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next) - if (f->before_jump != 0 - && PREV_INSN (f->target_rtl) == 0 - /* Label has still not appeared. If we are exiting a block with - a stack level to restore, that started before the fixup, - mark this stack level as needing restoration - when the fixup is later finalized. - Also mark the cleanup_list_list element for F - that corresponds to this block, so that ultimately - this block's cleanups will be executed by the code above. */ - && thisblock != 0 - /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, - it means the label is undefined. That's erroneous, but possible. */ - && (thisblock->data.block.block_start_count - <= f->block_start_count)) - { - tree lists = f->cleanup_list_list; - for (; lists; lists = TREE_CHAIN (lists)) - /* If the following elt. corresponds to our containing block - then the elt. must be for this block. */ - if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups) - TREE_ADDRESSABLE (lists) = 1; - - if (stack_level) - f->stack_level = stack_level; - } -} - -/* Generate RTL for an asm statement (explicit assembler code). - BODY is a STRING_CST node containing the assembler code text, - or an ADDR_EXPR containing a STRING_CST. */ - -void -expand_asm (body) - tree body; -{ - if (TREE_CODE (body) == ADDR_EXPR) - body = TREE_OPERAND (body, 0); - - emit_insn (gen_rtx (ASM_INPUT, VOIDmode, - TREE_STRING_POINTER (body))); - last_expr_type = 0; -} - -/* Generate RTL for an asm statement with arguments. - STRING is the instruction template. - OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs. - Each output or input has an expression in the TREE_VALUE and - a constraint-string in the TREE_PURPOSE. - CLOBBERS is a list of STRING_CST nodes each naming a hard register - that is clobbered by this insn. - - Not all kinds of lvalue that may appear in OUTPUTS can be stored directly. - Some elements of OUTPUTS may be replaced with trees representing temporary - values. The caller should copy those temporary values to the originally - specified lvalues. - - VOL nonzero means the insn is volatile; don't optimize it. */ - -void -expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line) - tree string, outputs, inputs, clobbers; - int vol; - char *filename; - int line; -{ - rtvec argvec, constraints; - rtx body; - int ninputs = list_length (inputs); - int noutputs = list_length (outputs); - int nclobbers; - tree tail; - register int i; - /* Vector of RTX's of evaluated output operands. */ - rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx)); - /* The insn we have emitted. */ - rtx insn; - - /* Count the number of meaningful clobbered registers, ignoring what - we would ignore later. */ - nclobbers = 0; - for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) - { - char *regname = TREE_STRING_POINTER (TREE_VALUE (tail)); - i = decode_reg_name (regname); - if (i >= 0 || i == -4) - ++nclobbers; - } - - last_expr_type = 0; - - for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) - { - tree val = TREE_VALUE (tail); - tree val1; - int j; - int found_equal; - - /* If there's an erroneous arg, emit no insn. */ - if (TREE_TYPE (val) == error_mark_node) - return; - - /* Make sure constraint has `=' and does not have `+'. */ - - found_equal = 0; - for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++) - { - if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+') - { - error ("output operand constraint contains `+'"); - return; - } - if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '=') - found_equal = 1; - } - if (! found_equal) - { - error ("output operand constraint lacks `='"); - return; - } - - /* If an output operand is not a variable or indirect ref, - or a part of one, - create a SAVE_EXPR which is a pseudo-reg - to act as an intermediate temporary. - Make the asm insn write into that, then copy it to - the real output operand. */ - - while (TREE_CODE (val) == COMPONENT_REF - || TREE_CODE (val) == ARRAY_REF) - val = TREE_OPERAND (val, 0); - - if (TREE_CODE (val) != VAR_DECL - && TREE_CODE (val) != PARM_DECL - && TREE_CODE (val) != INDIRECT_REF) - { - TREE_VALUE (tail) = save_expr (TREE_VALUE (tail)); - /* If it's a constant, print error now so don't crash later. */ - if (TREE_CODE (TREE_VALUE (tail)) != SAVE_EXPR) - { - error ("invalid output in `asm'"); - return; - } - } - - output_rtx[i] = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0); - } - - if (ninputs + noutputs > MAX_RECOG_OPERANDS) - { - error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS); - return; - } - - /* Make vectors for the expression-rtx and constraint strings. */ - - argvec = rtvec_alloc (ninputs); - constraints = rtvec_alloc (ninputs); - - body = gen_rtx (ASM_OPERANDS, VOIDmode, - TREE_STRING_POINTER (string), "", 0, argvec, constraints, - filename, line); - MEM_VOLATILE_P (body) = vol; - - /* Eval the inputs and put them into ARGVEC. - Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */ - - i = 0; - for (tail = inputs; tail; tail = TREE_CHAIN (tail)) - { - int j; - - /* If there's an erroneous arg, emit no insn, - because the ASM_INPUT would get VOIDmode - and that could cause a crash in reload. */ - if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node) - return; - if (TREE_PURPOSE (tail) == NULL_TREE) - { - error ("hard register `%s' listed as input operand to `asm'", - TREE_STRING_POINTER (TREE_VALUE (tail)) ); - return; - } - - /* Make sure constraint has neither `=' nor `+'. */ - - for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++) - if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '=' - || TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+') - { - error ("input operand constraint contains `%c'", - TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]); - return; - } - - XVECEXP (body, 3, i) /* argvec */ - = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0); - XVECEXP (body, 4, i) /* constraints */ - = gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), - TREE_STRING_POINTER (TREE_PURPOSE (tail))); - i++; - } - - /* Protect all the operands from the queue, - now that they have all been evaluated. */ - - for (i = 0; i < ninputs; i++) - XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0); - - for (i = 0; i < noutputs; i++) - output_rtx[i] = protect_from_queue (output_rtx[i], 1); - - /* Now, for each output, construct an rtx - (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT - ARGVEC CONSTRAINTS)) - If there is more than one, put them inside a PARALLEL. */ - - if (noutputs == 1 && nclobbers == 0) - { - XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs)); - insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body)); - } - else if (noutputs == 0 && nclobbers == 0) - { - /* No output operands: put in a raw ASM_OPERANDS rtx. */ - insn = emit_insn (body); - } - else - { - rtx obody = body; - int num = noutputs; - if (num == 0) num = 1; - body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers)); - - /* For each output operand, store a SET. */ - - for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) - { - XVECEXP (body, 0, i) - = gen_rtx (SET, VOIDmode, - output_rtx[i], - gen_rtx (ASM_OPERANDS, VOIDmode, - TREE_STRING_POINTER (string), - TREE_STRING_POINTER (TREE_PURPOSE (tail)), - i, argvec, constraints, - filename, line)); - MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol; - } - - /* If there are no outputs (but there are some clobbers) - store the bare ASM_OPERANDS into the PARALLEL. */ - - if (i == 0) - XVECEXP (body, 0, i++) = obody; - - /* Store (clobber REG) for each clobbered register specified. */ - - for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) - { - char *regname = TREE_STRING_POINTER (TREE_VALUE (tail)); - int j = decode_reg_name (regname); - - if (j < 0) - { - if (j == -3) /* `cc', which is not a register */ - continue; - - if (j == -4) /* `memory', don't cache memory across asm */ - { - XVECEXP (body, 0, i++) - = gen_rtx (CLOBBER, VOIDmode, - gen_rtx (MEM, QImode, - gen_rtx (SCRATCH, VOIDmode, 0))); - continue; - } - - error ("unknown register name `%s' in `asm'", regname); - return; - } - - /* Use QImode since that's guaranteed to clobber just one reg. */ - XVECEXP (body, 0, i++) - = gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j)); - } - - insn = emit_insn (body); - } - - free_temp_slots (); -} - -/* Generate RTL to evaluate the expression EXP - and remember it in case this is the VALUE in a ({... VALUE; }) constr. */ - -void -expand_expr_stmt (exp) - tree exp; -{ - /* If -W, warn about statements with no side effects, - except for an explicit cast to void (e.g. for assert()), and - except inside a ({...}) where they may be useful. */ - if (expr_stmts_for_value == 0 && exp != error_mark_node) - { - if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused) - && !(TREE_CODE (exp) == CONVERT_EXPR - && TREE_TYPE (exp) == void_type_node)) - warning_with_file_and_line (emit_filename, emit_lineno, - "statement with no effect"); - else if (warn_unused) - warn_if_unused_value (exp); - } - last_expr_type = TREE_TYPE (exp); - if (! flag_syntax_only) - last_expr_value = expand_expr (exp, - (expr_stmts_for_value - ? NULL_RTX : const0_rtx), - VOIDmode, 0); - - /* If all we do is reference a volatile value in memory, - copy it to a register to be sure it is actually touched. */ - if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM - && TREE_THIS_VOLATILE (exp)) - { - if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode) - ; - else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode) - copy_to_reg (last_expr_value); - else - { - rtx lab = gen_label_rtx (); - - /* Compare the value with itself to reference it. */ - emit_cmp_insn (last_expr_value, last_expr_value, EQ, - expand_expr (TYPE_SIZE (last_expr_type), - NULL_RTX, VOIDmode, 0), - BLKmode, 0, - TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT); - emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab)); - emit_label (lab); - } - } - - /* If this expression is part of a ({...}) and is in memory, we may have - to preserve temporaries. */ - preserve_temp_slots (last_expr_value); - - /* Free any temporaries used to evaluate this expression. Any temporary - used as a result of this expression will already have been preserved - above. */ - free_temp_slots (); - - emit_queue (); -} - -/* Warn if EXP contains any computations whose results are not used. - Return 1 if a warning is printed; 0 otherwise. */ - -static int -warn_if_unused_value (exp) - tree exp; -{ - if (TREE_USED (exp)) - return 0; - - switch (TREE_CODE (exp)) - { - case PREINCREMENT_EXPR: - case POSTINCREMENT_EXPR: - case PREDECREMENT_EXPR: - case POSTDECREMENT_EXPR: - case MODIFY_EXPR: - case INIT_EXPR: - case TARGET_EXPR: - case CALL_EXPR: - case METHOD_CALL_EXPR: - case RTL_EXPR: - case WITH_CLEANUP_EXPR: - case EXIT_EXPR: - /* We don't warn about COND_EXPR because it may be a useful - construct if either arm contains a side effect. */ - case COND_EXPR: - return 0; - - case BIND_EXPR: - /* For a binding, warn if no side effect within it. */ - return warn_if_unused_value (TREE_OPERAND (exp, 1)); - - case TRUTH_ORIF_EXPR: - case TRUTH_ANDIF_EXPR: - /* In && or ||, warn if 2nd operand has no side effect. */ - return warn_if_unused_value (TREE_OPERAND (exp, 1)); - - case COMPOUND_EXPR: - if (warn_if_unused_value (TREE_OPERAND (exp, 0))) - return 1; - /* Let people do `(foo (), 0)' without a warning. */ - if (TREE_CONSTANT (TREE_OPERAND (exp, 1))) - return 0; - return warn_if_unused_value (TREE_OPERAND (exp, 1)); - - case NOP_EXPR: - case CONVERT_EXPR: - case NON_LVALUE_EXPR: - /* Don't warn about values cast to void. */ - if (TREE_TYPE (exp) == void_type_node) - return 0; - /* Don't warn about conversions not explicit in the user's program. */ - if (TREE_NO_UNUSED_WARNING (exp)) - return 0; - /* Assignment to a cast usually results in a cast of a modify. - Don't complain about that. */ - if (TREE_CODE (TREE_OPERAND (exp, 0)) == MODIFY_EXPR) - return 0; - /* Sometimes it results in a cast of a cast of a modify. - Don't complain about that. */ - if ((TREE_CODE (TREE_OPERAND (exp, 0)) == CONVERT_EXPR - || TREE_CODE (TREE_OPERAND (exp, 0)) == NOP_EXPR) - && TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0)) == MODIFY_EXPR) - return 0; - - default: - /* Referencing a volatile value is a side effect, so don't warn. */ - if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd' - || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r') - && TREE_THIS_VOLATILE (exp)) - return 0; - warning_with_file_and_line (emit_filename, emit_lineno, - "value computed is not used"); - return 1; - } -} - -/* Clear out the memory of the last expression evaluated. */ - -void -clear_last_expr () -{ - last_expr_type = 0; -} - -/* Begin a statement which will return a value. - Return the RTL_EXPR for this statement expr. - The caller must save that value and pass it to expand_end_stmt_expr. */ - -tree -expand_start_stmt_expr () -{ - /* Make the RTL_EXPR node temporary, not momentary, - so that rtl_expr_chain doesn't become garbage. */ - int momentary = suspend_momentary (); - tree t = make_node (RTL_EXPR); - resume_momentary (momentary); - start_sequence (); - NO_DEFER_POP; - expr_stmts_for_value++; - return t; -} - -/* Restore the previous state at the end of a statement that returns a value. - Returns a tree node representing the statement's value and the - insns to compute the value. - - The nodes of that expression have been freed by now, so we cannot use them. - But we don't want to do that anyway; the expression has already been - evaluated and now we just want to use the value. So generate a RTL_EXPR - with the proper type and RTL value. - - If the last substatement was not an expression, - return something with type `void'. */ - -tree -expand_end_stmt_expr (t) - tree t; -{ - OK_DEFER_POP; - - if (last_expr_type == 0) - { - last_expr_type = void_type_node; - last_expr_value = const0_rtx; - } - else if (last_expr_value == 0) - /* There are some cases where this can happen, such as when the - statement is void type. */ - last_expr_value = const0_rtx; - else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value)) - /* Remove any possible QUEUED. */ - last_expr_value = protect_from_queue (last_expr_value, 0); - - emit_queue (); - - TREE_TYPE (t) = last_expr_type; - RTL_EXPR_RTL (t) = last_expr_value; - RTL_EXPR_SEQUENCE (t) = get_insns (); - - rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain); - - end_sequence (); - - /* Don't consider deleting this expr or containing exprs at tree level. */ - TREE_SIDE_EFFECTS (t) = 1; - /* Propagate volatility of the actual RTL expr. */ - TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value); - - last_expr_type = 0; - expr_stmts_for_value--; - - return t; -} - -/* The exception handling nesting looks like this: - - <-- Level N-1 - { <-- exception handler block - <-- Level N - <-- in an exception handler - { <-- try block - : <-- in a TRY block - : <-- in an exception handler - : - } - - { <-- except block - : <-- in an except block - : <-- in an exception handler - : - } - - } -*/ - -/* Return nonzero iff in a try block at level LEVEL. */ - -int -in_try_block (level) - int level; -{ - struct nesting *n = except_stack; - while (1) - { - while (n && n->data.except_stmt.after_label != 0) - n = n->next; - if (n == 0) - return 0; - if (level == 0) - return n != 0; - level--; - n = n->next; - } -} - -/* Return nonzero iff in an except block at level LEVEL. */ - -int -in_except_block (level) - int level; -{ - struct nesting *n = except_stack; - while (1) - { - while (n && n->data.except_stmt.after_label == 0) - n = n->next; - if (n == 0) - return 0; - if (level == 0) - return n != 0; - level--; - n = n->next; - } -} - -/* Return nonzero iff in an exception handler at level LEVEL. */ - -int -in_exception_handler (level) - int level; -{ - struct nesting *n = except_stack; - while (n && level--) - n = n->next; - return n != 0; -} - -/* Record the fact that the current exception nesting raises - exception EX. If not in an exception handler, return 0. */ -int -expand_raise (ex) - tree ex; -{ - tree *raises_ptr; - - if (except_stack == 0) - return 0; - raises_ptr = &except_stack->data.except_stmt.raised; - if (! value_member (ex, *raises_ptr)) - *raises_ptr = tree_cons (NULL_TREE, ex, *raises_ptr); - return 1; -} - -/* Generate RTL for the start of a try block. - - TRY_CLAUSE is the condition to test to enter the try block. */ - -void -expand_start_try (try_clause, exitflag, escapeflag) - tree try_clause; - int exitflag; - int escapeflag; -{ - struct nesting *thishandler = ALLOC_NESTING (); - - /* Make an entry on cond_stack for the cond we are entering. */ - - thishandler->next = except_stack; - thishandler->all = nesting_stack; - thishandler->depth = ++nesting_depth; - thishandler->data.except_stmt.raised = 0; - thishandler->data.except_stmt.handled = 0; - thishandler->data.except_stmt.first_insn = get_insns (); - thishandler->data.except_stmt.except_label = gen_label_rtx (); - thishandler->data.except_stmt.unhandled_label = 0; - thishandler->data.except_stmt.after_label = 0; - thishandler->data.except_stmt.escape_label - = escapeflag ? thishandler->data.except_stmt.except_label : 0; - thishandler->exit_label = exitflag ? gen_label_rtx () : 0; - except_stack = thishandler; - nesting_stack = thishandler; - - do_jump (try_clause, thishandler->data.except_stmt.except_label, NULL_RTX); -} - -/* End of a TRY block. Nothing to do for now. */ - -void -expand_end_try () -{ - except_stack->data.except_stmt.after_label = gen_label_rtx (); - expand_goto_internal (NULL_TREE, except_stack->data.except_stmt.after_label, - NULL_RTX); -} - -/* Start an `except' nesting contour. - EXITFLAG says whether this contour should be able to `exit' something. - ESCAPEFLAG says whether this contour should be escapable. */ - -void -expand_start_except (exitflag, escapeflag) - int exitflag; - int escapeflag; -{ - if (exitflag) - { - struct nesting *n; - /* An `exit' from catch clauses goes out to next exit level, - if there is one. Otherwise, it just goes to the end - of the construct. */ - for (n = except_stack->next; n; n = n->next) - if (n->exit_label != 0) - { - except_stack->exit_label = n->exit_label; - break; - } - if (n == 0) - except_stack->exit_label = except_stack->data.except_stmt.after_label; - } - if (escapeflag) - { - struct nesting *n; - /* An `escape' from catch clauses goes out to next escape level, - if there is one. Otherwise, it just goes to the end - of the construct. */ - for (n = except_stack->next; n; n = n->next) - if (n->data.except_stmt.escape_label != 0) - { - except_stack->data.except_stmt.escape_label - = n->data.except_stmt.escape_label; - break; - } - if (n == 0) - except_stack->data.except_stmt.escape_label - = except_stack->data.except_stmt.after_label; - } - do_pending_stack_adjust (); - emit_label (except_stack->data.except_stmt.except_label); -} - -/* Generate code to `escape' from an exception contour. This - is like `exiting', but does not conflict with constructs which - use `exit_label'. - - Return nonzero if this contour is escapable, otherwise - return zero, and language-specific code will emit the - appropriate error message. */ -int -expand_escape_except () -{ - struct nesting *n; - last_expr_type = 0; - for (n = except_stack; n; n = n->next) - if (n->data.except_stmt.escape_label != 0) - { - expand_goto_internal (NULL_TREE, - n->data.except_stmt.escape_label, NULL_RTX); - return 1; - } - - return 0; -} - -/* Finish processing and `except' contour. - Culls out all exceptions which might be raise but not - handled, and returns the list to the caller. - Language-specific code is responsible for dealing with these - exceptions. */ - -tree -expand_end_except () -{ - struct nesting *n; - tree raised = NULL_TREE; - - do_pending_stack_adjust (); - emit_label (except_stack->data.except_stmt.after_label); - - n = except_stack->next; - if (n) - { - /* Propagate exceptions raised but not handled to next - highest level. */ - tree handled = except_stack->data.except_stmt.raised; - if (handled != void_type_node) - { - tree prev = NULL_TREE; - raised = except_stack->data.except_stmt.raised; - while (handled) - { - tree this_raise; - for (this_raise = raised, prev = 0; this_raise; - this_raise = TREE_CHAIN (this_raise)) - { - if (value_member (TREE_VALUE (this_raise), handled)) - { - if (prev) - TREE_CHAIN (prev) = TREE_CHAIN (this_raise); - else - { - raised = TREE_CHAIN (raised); - if (raised == NULL_TREE) - goto nada; - } - } - else - prev = this_raise; - } - handled = TREE_CHAIN (handled); - } - if (prev == NULL_TREE) - prev = raised; - if (prev) - TREE_CHAIN (prev) = n->data.except_stmt.raised; - nada: - n->data.except_stmt.raised = raised; - } - } - - POPSTACK (except_stack); - last_expr_type = 0; - return raised; -} - -/* Record that exception EX is caught by this exception handler. - Return nonzero if in exception handling construct, otherwise return 0. */ -int -expand_catch (ex) - tree ex; -{ - tree *raises_ptr; - - if (except_stack == 0) - return 0; - raises_ptr = &except_stack->data.except_stmt.handled; - if (*raises_ptr != void_type_node - && ex != NULL_TREE - && ! value_member (ex, *raises_ptr)) - *raises_ptr = tree_cons (NULL_TREE, ex, *raises_ptr); - return 1; -} - -/* Record that this exception handler catches all exceptions. - Return nonzero if in exception handling construct, otherwise return 0. */ - -int -expand_catch_default () -{ - if (except_stack == 0) - return 0; - except_stack->data.except_stmt.handled = void_type_node; - return 1; -} - -int -expand_end_catch () -{ - if (except_stack == 0 || except_stack->data.except_stmt.after_label == 0) - return 0; - expand_goto_internal (NULL_TREE, except_stack->data.except_stmt.after_label, - NULL_RTX); - return 1; -} - -/* Generate RTL for the start of an if-then. COND is the expression - whose truth should be tested. - - If EXITFLAG is nonzero, this conditional is visible to - `exit_something'. */ - -void -expand_start_cond (cond, exitflag) - tree cond; - int exitflag; -{ - struct nesting *thiscond = ALLOC_NESTING (); - - /* Make an entry on cond_stack for the cond we are entering. */ - - thiscond->next = cond_stack; - thiscond->all = nesting_stack; - thiscond->depth = ++nesting_depth; - thiscond->data.cond.next_label = gen_label_rtx (); - /* Before we encounter an `else', we don't need a separate exit label - unless there are supposed to be exit statements - to exit this conditional. */ - thiscond->exit_label = exitflag ? gen_label_rtx () : 0; - thiscond->data.cond.endif_label = thiscond->exit_label; - cond_stack = thiscond; - nesting_stack = thiscond; - - do_jump (cond, thiscond->data.cond.next_label, NULL_RTX); -} - -/* Generate RTL between then-clause and the elseif-clause - of an if-then-elseif-.... */ - -void -expand_start_elseif (cond) - tree cond; -{ - if (cond_stack->data.cond.endif_label == 0) - cond_stack->data.cond.endif_label = gen_label_rtx (); - emit_jump (cond_stack->data.cond.endif_label); - emit_label (cond_stack->data.cond.next_label); - cond_stack->data.cond.next_label = gen_label_rtx (); - do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX); -} - -/* Generate RTL between the then-clause and the else-clause - of an if-then-else. */ - -void -expand_start_else () -{ - if (cond_stack->data.cond.endif_label == 0) - cond_stack->data.cond.endif_label = gen_label_rtx (); - emit_jump (cond_stack->data.cond.endif_label); - emit_label (cond_stack->data.cond.next_label); - cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */ -} - -/* Generate RTL for the end of an if-then. - Pop the record for it off of cond_stack. */ - -void -expand_end_cond () -{ - struct nesting *thiscond = cond_stack; - - do_pending_stack_adjust (); - if (thiscond->data.cond.next_label) - emit_label (thiscond->data.cond.next_label); - if (thiscond->data.cond.endif_label) - emit_label (thiscond->data.cond.endif_label); - - POPSTACK (cond_stack); - last_expr_type = 0; -} - -/* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this - loop should be exited by `exit_something'. This is a loop for which - `expand_continue' will jump to the top of the loop. - - Make an entry on loop_stack to record the labels associated with - this loop. */ - -struct nesting * -expand_start_loop (exit_flag) - int exit_flag; -{ - register struct nesting *thisloop = ALLOC_NESTING (); - - /* Make an entry on loop_stack for the loop we are entering. */ - - thisloop->next = loop_stack; - thisloop->all = nesting_stack; - thisloop->depth = ++nesting_depth; - thisloop->data.loop.start_label = gen_label_rtx (); - thisloop->data.loop.end_label = gen_label_rtx (); - thisloop->data.loop.continue_label = thisloop->data.loop.start_label; - thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0; - loop_stack = thisloop; - nesting_stack = thisloop; - - do_pending_stack_adjust (); - emit_queue (); - emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG); - emit_label (thisloop->data.loop.start_label); - - return thisloop; -} - -/* Like expand_start_loop but for a loop where the continuation point - (for expand_continue_loop) will be specified explicitly. */ - -struct nesting * -expand_start_loop_continue_elsewhere (exit_flag) - int exit_flag; -{ - struct nesting *thisloop = expand_start_loop (exit_flag); - loop_stack->data.loop.continue_label = gen_label_rtx (); - return thisloop; -} - -/* Specify the continuation point for a loop started with - expand_start_loop_continue_elsewhere. - Use this at the point in the code to which a continue statement - should jump. */ - -void -expand_loop_continue_here () -{ - do_pending_stack_adjust (); - emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT); - emit_label (loop_stack->data.loop.continue_label); -} - -/* Finish a loop. Generate a jump back to the top and the loop-exit label. - Pop the block off of loop_stack. */ - -void -expand_end_loop () -{ - register rtx insn = get_last_insn (); - register rtx start_label = loop_stack->data.loop.start_label; - rtx last_test_insn = 0; - int num_insns = 0; - - /* Mark the continue-point at the top of the loop if none elsewhere. */ - if (start_label == loop_stack->data.loop.continue_label) - emit_note_before (NOTE_INSN_LOOP_CONT, start_label); - - do_pending_stack_adjust (); - - /* If optimizing, perhaps reorder the loop. If the loop - starts with a conditional exit, roll that to the end - where it will optimize together with the jump back. - - We look for the last conditional branch to the exit that we encounter - before hitting 30 insns or a CALL_INSN. If we see an unconditional - branch to the exit first, use it. - - We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes - because moving them is not valid. */ - - if (optimize - && - ! (GET_CODE (insn) == JUMP_INSN - && GET_CODE (PATTERN (insn)) == SET - && SET_DEST (PATTERN (insn)) == pc_rtx - && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)) - { - /* Scan insns from the top of the loop looking for a qualified - conditional exit. */ - for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn; - insn = NEXT_INSN (insn)) - { - if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL) - break; - - if (GET_CODE (insn) == NOTE - && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG - || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)) - break; - - if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN) - num_insns++; - - if (last_test_insn && num_insns > 30) - break; - - if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET - && SET_DEST (PATTERN (insn)) == pc_rtx - && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE - && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF - && (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0) - == loop_stack->data.loop.end_label)) - || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF - && (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0) - == loop_stack->data.loop.end_label)))) - last_test_insn = insn; - - if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN - && GET_CODE (PATTERN (insn)) == SET - && SET_DEST (PATTERN (insn)) == pc_rtx - && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF - && (XEXP (SET_SRC (PATTERN (insn)), 0) - == loop_stack->data.loop.end_label)) - /* Include BARRIER. */ - last_test_insn = NEXT_INSN (insn); - } - - if (last_test_insn != 0 && last_test_insn != get_last_insn ()) - { - /* We found one. Move everything from there up - to the end of the loop, and add a jump into the loop - to jump to there. */ - register rtx newstart_label = gen_label_rtx (); - register rtx start_move = start_label; - - /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note, - then we want to move this note also. */ - if (GET_CODE (PREV_INSN (start_move)) == NOTE - && (NOTE_LINE_NUMBER (PREV_INSN (start_move)) - == NOTE_INSN_LOOP_CONT)) - start_move = PREV_INSN (start_move); - - emit_label_after (newstart_label, PREV_INSN (start_move)); - reorder_insns (start_move, last_test_insn, get_last_insn ()); - emit_jump_insn_after (gen_jump (start_label), - PREV_INSN (newstart_label)); - emit_barrier_after (PREV_INSN (newstart_label)); - start_label = newstart_label; - } - } - - emit_jump (start_label); - emit_note (NULL_PTR, NOTE_INSN_LOOP_END); - emit_label (loop_stack->data.loop.end_label); - - POPSTACK (loop_stack); - - last_expr_type = 0; -} - -/* Generate a jump to the current loop's continue-point. - This is usually the top of the loop, but may be specified - explicitly elsewhere. If not currently inside a loop, - return 0 and do nothing; caller will print an error message. */ - -int -expand_continue_loop (whichloop) - struct nesting *whichloop; -{ - last_expr_type = 0; - if (whichloop == 0) - whichloop = loop_stack; - if (whichloop == 0) - return 0; - expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label, - NULL_RTX); - return 1; -} - -/* Generate a jump to exit the current loop. If not currently inside a loop, - return 0 and do nothing; caller will print an error message. */ - -int -expand_exit_loop (whichloop) - struct nesting *whichloop; -{ - last_expr_type = 0; - if (whichloop == 0) - whichloop = loop_stack; - if (whichloop == 0) - return 0; - expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX); - return 1; -} - -/* Generate a conditional jump to exit the current loop if COND - evaluates to zero. If not currently inside a loop, - return 0 and do nothing; caller will print an error message. */ - -int -expand_exit_loop_if_false (whichloop, cond) - struct nesting *whichloop; - tree cond; -{ - last_expr_type = 0; - if (whichloop == 0) - whichloop = loop_stack; - if (whichloop == 0) - return 0; - do_jump (cond, whichloop->data.loop.end_label, NULL_RTX); - return 1; -} - -/* Return non-zero if we should preserve sub-expressions as separate - pseudos. We never do so if we aren't optimizing. We always do so - if -fexpensive-optimizations. - - Otherwise, we only do so if we are in the "early" part of a loop. I.e., - the loop may still be a small one. */ - -int -preserve_subexpressions_p () -{ - rtx insn; - - if (flag_expensive_optimizations) - return 1; - - if (optimize == 0 || loop_stack == 0) - return 0; - - insn = get_last_insn_anywhere (); - - return (insn - && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label) - < n_non_fixed_regs * 3)); - -} - -/* Generate a jump to exit the current loop, conditional, binding contour - or case statement. Not all such constructs are visible to this function, - only those started with EXIT_FLAG nonzero. Individual languages use - the EXIT_FLAG parameter to control which kinds of constructs you can - exit this way. - - If not currently inside anything that can be exited, - return 0 and do nothing; caller will print an error message. */ - -int -expand_exit_something () -{ - struct nesting *n; - last_expr_type = 0; - for (n = nesting_stack; n; n = n->all) - if (n->exit_label != 0) - { - expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX); - return 1; - } - - return 0; -} - -/* Generate RTL to return from the current function, with no value. - (That is, we do not do anything about returning any value.) */ - -void -expand_null_return () -{ - struct nesting *block = block_stack; - rtx last_insn = 0; - - /* Does any pending block have cleanups? */ - - while (block && block->data.block.cleanups == 0) - block = block->next; - - /* If yes, use a goto to return, since that runs cleanups. */ - - expand_null_return_1 (last_insn, block != 0); -} - -/* Generate RTL to return from the current function, with value VAL. */ - -void -expand_value_return (val) - rtx val; -{ - struct nesting *block = block_stack; - rtx last_insn = get_last_insn (); - rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl)); - - /* Copy the value to the return location - unless it's already there. */ - - if (return_reg != val) - { -#ifdef PROMOTE_FUNCTION_RETURN - enum machine_mode mode = DECL_MODE (DECL_RESULT (current_function_decl)); - tree type = TREE_TYPE (DECL_RESULT (current_function_decl)); - int unsignedp = TREE_UNSIGNED (type); - - if (TREE_CODE (type) == INTEGER_TYPE || TREE_CODE (type) == ENUMERAL_TYPE - || TREE_CODE (type) == BOOLEAN_TYPE || TREE_CODE (type) == CHAR_TYPE - || TREE_CODE (type) == REAL_TYPE || TREE_CODE (type) == POINTER_TYPE - || TREE_CODE (type) == OFFSET_TYPE) - { - PROMOTE_MODE (mode, unsignedp, type); - } - - if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode) - convert_move (return_reg, val, unsignedp); - else -#endif - emit_move_insn (return_reg, val); - } - if (GET_CODE (return_reg) == REG - && REGNO (return_reg) < FIRST_PSEUDO_REGISTER) - emit_insn (gen_rtx (USE, VOIDmode, return_reg)); - - /* Does any pending block have cleanups? */ - - while (block && block->data.block.cleanups == 0) - block = block->next; - - /* If yes, use a goto to return, since that runs cleanups. - Use LAST_INSN to put cleanups *before* the move insn emitted above. */ - - expand_null_return_1 (last_insn, block != 0); -} - -/* Output a return with no value. If LAST_INSN is nonzero, - pretend that the return takes place after LAST_INSN. - If USE_GOTO is nonzero then don't use a return instruction; - go to the return label instead. This causes any cleanups - of pending blocks to be executed normally. */ - -static void -expand_null_return_1 (last_insn, use_goto) - rtx last_insn; - int use_goto; -{ - rtx end_label = cleanup_label ? cleanup_label : return_label; - - clear_pending_stack_adjust (); - do_pending_stack_adjust (); - last_expr_type = 0; - - /* PCC-struct return always uses an epilogue. */ - if (current_function_returns_pcc_struct || use_goto) - { - if (end_label == 0) - end_label = return_label = gen_label_rtx (); - expand_goto_internal (NULL_TREE, end_label, last_insn); - return; - } - - /* Otherwise output a simple return-insn if one is available, - unless it won't do the job. */ -#ifdef HAVE_return - if (HAVE_return && use_goto == 0 && cleanup_label == 0) - { - emit_jump_insn (gen_return ()); - emit_barrier (); - return; - } -#endif - - /* Otherwise jump to the epilogue. */ - expand_goto_internal (NULL_TREE, end_label, last_insn); -} - -/* Generate RTL to evaluate the expression RETVAL and return it - from the current function. */ - -void -expand_return (retval) - tree retval; -{ - /* If there are any cleanups to be performed, then they will - be inserted following LAST_INSN. It is desirable - that the last_insn, for such purposes, should be the - last insn before computing the return value. Otherwise, cleanups - which call functions can clobber the return value. */ - /* ??? rms: I think that is erroneous, because in C++ it would - run destructors on variables that might be used in the subsequent - computation of the return value. */ - rtx last_insn = 0; - register rtx val = 0; - register rtx op0; - tree retval_rhs; - int cleanups; - struct nesting *block; - - /* If function wants no value, give it none. */ - if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE) - { - expand_expr (retval, NULL_RTX, VOIDmode, 0); - emit_queue (); - expand_null_return (); - return; - } - - /* Are any cleanups needed? E.g. C++ destructors to be run? */ - cleanups = any_pending_cleanups (1); - - if (TREE_CODE (retval) == RESULT_DECL) - retval_rhs = retval; - else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR) - && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL) - retval_rhs = TREE_OPERAND (retval, 1); - else if (TREE_TYPE (retval) == void_type_node) - /* Recognize tail-recursive call to void function. */ - retval_rhs = retval; - else - retval_rhs = NULL_TREE; - - /* Only use `last_insn' if there are cleanups which must be run. */ - if (cleanups || cleanup_label != 0) - last_insn = get_last_insn (); - - /* Distribute return down conditional expr if either of the sides - may involve tail recursion (see test below). This enhances the number - of tail recursions we see. Don't do this always since it can produce - sub-optimal code in some cases and we distribute assignments into - conditional expressions when it would help. */ - - if (optimize && retval_rhs != 0 - && frame_offset == 0 - && TREE_CODE (retval_rhs) == COND_EXPR - && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR - || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR)) - { - rtx label = gen_label_rtx (); - do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX); - expand_return (build (MODIFY_EXPR, TREE_TYPE (current_function_decl), - DECL_RESULT (current_function_decl), - TREE_OPERAND (retval_rhs, 1))); - emit_label (label); - expand_return (build (MODIFY_EXPR, TREE_TYPE (current_function_decl), - DECL_RESULT (current_function_decl), - TREE_OPERAND (retval_rhs, 2))); - return; - } - - /* For tail-recursive call to current function, - just jump back to the beginning. - It's unsafe if any auto variable in this function - has its address taken; for simplicity, - require stack frame to be empty. */ - if (optimize && retval_rhs != 0 - && frame_offset == 0 - && TREE_CODE (retval_rhs) == CALL_EXPR - && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR - && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl - /* Finish checking validity, and if valid emit code - to set the argument variables for the new call. */ - && tail_recursion_args (TREE_OPERAND (retval_rhs, 1), - DECL_ARGUMENTS (current_function_decl))) - { - if (tail_recursion_label == 0) - { - tail_recursion_label = gen_label_rtx (); - emit_label_after (tail_recursion_label, - tail_recursion_reentry); - } - emit_queue (); - expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn); - emit_barrier (); - return; - } -#ifdef HAVE_return - /* This optimization is safe if there are local cleanups - because expand_null_return takes care of them. - ??? I think it should also be safe when there is a cleanup label, - because expand_null_return takes care of them, too. - Any reason why not? */ - if (HAVE_return && cleanup_label == 0 - && ! current_function_returns_pcc_struct) - { - /* If this is return x == y; then generate - if (x == y) return 1; else return 0; - if we can do it with explicit return insns. */ - if (retval_rhs) - switch (TREE_CODE (retval_rhs)) - { - case EQ_EXPR: - case NE_EXPR: - case GT_EXPR: - case GE_EXPR: - case LT_EXPR: - case LE_EXPR: - case TRUTH_ANDIF_EXPR: - case TRUTH_ORIF_EXPR: - case TRUTH_AND_EXPR: - case TRUTH_OR_EXPR: - case TRUTH_NOT_EXPR: - case TRUTH_XOR_EXPR: - op0 = gen_label_rtx (); - jumpifnot (retval_rhs, op0); - expand_value_return (const1_rtx); - emit_label (op0); - expand_value_return (const0_rtx); - return; - } - } -#endif /* HAVE_return */ - - if (cleanups - && retval_rhs != 0 - && TREE_TYPE (retval_rhs) != void_type_node - && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG) - { - /* Calculate the return value into a pseudo reg. */ - val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0); - emit_queue (); - /* All temporaries have now been used. */ - free_temp_slots (); - /* Return the calculated value, doing cleanups first. */ - expand_value_return (val); - } - else - { - /* No cleanups or no hard reg used; - calculate value into hard return reg. */ - expand_expr (retval, NULL_RTX, VOIDmode, 0); - emit_queue (); - free_temp_slots (); - expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl))); - } -} - -/* Return 1 if the end of the generated RTX is not a barrier. - This means code already compiled can drop through. */ - -int -drop_through_at_end_p () -{ - rtx insn = get_last_insn (); - while (insn && GET_CODE (insn) == NOTE) - insn = PREV_INSN (insn); - return insn && GET_CODE (insn) != BARRIER; -} - -/* Emit code to alter this function's formal parms for a tail-recursive call. - ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs). - FORMALS is the chain of decls of formals. - Return 1 if this can be done; - otherwise return 0 and do not emit any code. */ - -static int -tail_recursion_args (actuals, formals) - tree actuals, formals; -{ - register tree a = actuals, f = formals; - register int i; - register rtx *argvec; - - /* Check that number and types of actuals are compatible - with the formals. This is not always true in valid C code. - Also check that no formal needs to be addressable - and that all formals are scalars. */ - - /* Also count the args. */ - - for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++) - { - if (TREE_TYPE (TREE_VALUE (a)) != TREE_TYPE (f)) - return 0; - if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode) - return 0; - } - if (a != 0 || f != 0) - return 0; - - /* Compute all the actuals. */ - - argvec = (rtx *) alloca (i * sizeof (rtx)); - - for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++) - argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0); - - /* Find which actual values refer to current values of previous formals. - Copy each of them now, before any formal is changed. */ - - for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++) - { - int copy = 0; - register int j; - for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++) - if (reg_mentioned_p (DECL_RTL (f), argvec[i])) - { copy = 1; break; } - if (copy) - argvec[i] = copy_to_reg (argvec[i]); - } - - /* Store the values of the actuals into the formals. */ - - for (f = formals, a = actuals, i = 0; f; - f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++) - { - if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i])) - emit_move_insn (DECL_RTL (f), argvec[i]); - else - convert_move (DECL_RTL (f), argvec[i], - TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a)))); - } - - free_temp_slots (); - return 1; -} - -/* Generate the RTL code for entering a binding contour. - The variables are declared one by one, by calls to `expand_decl'. - - EXIT_FLAG is nonzero if this construct should be visible to - `exit_something'. */ - -void -expand_start_bindings (exit_flag) - int exit_flag; -{ - struct nesting *thisblock = ALLOC_NESTING (); - - rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG); - - /* Make an entry on block_stack for the block we are entering. */ - - thisblock->next = block_stack; - thisblock->all = nesting_stack; - thisblock->depth = ++nesting_depth; - thisblock->data.block.stack_level = 0; - thisblock->data.block.cleanups = 0; - thisblock->data.block.function_call_count = 0; -#if 0 - if (block_stack) - { - if (block_stack->data.block.cleanups == NULL_TREE - && (block_stack->data.block.outer_cleanups == NULL_TREE - || block_stack->data.block.outer_cleanups == empty_cleanup_list)) - thisblock->data.block.outer_cleanups = empty_cleanup_list; - else - thisblock->data.block.outer_cleanups - = tree_cons (NULL_TREE, block_stack->data.block.cleanups, - block_stack->data.block.outer_cleanups); - } - else - thisblock->data.block.outer_cleanups = 0; -#endif -#if 1 - if (block_stack - && !(block_stack->data.block.cleanups == NULL_TREE - && block_stack->data.block.outer_cleanups == NULL_TREE)) - thisblock->data.block.outer_cleanups - = tree_cons (NULL_TREE, block_stack->data.block.cleanups, - block_stack->data.block.outer_cleanups); - else - thisblock->data.block.outer_cleanups = 0; -#endif - thisblock->data.block.label_chain = 0; - thisblock->data.block.innermost_stack_block = stack_block_stack; - thisblock->data.block.first_insn = note; - thisblock->data.block.block_start_count = ++block_start_count; - thisblock->exit_label = exit_flag ? gen_label_rtx () : 0; - block_stack = thisblock; - nesting_stack = thisblock; - - /* Make a new level for allocating stack slots. */ - push_temp_slots (); -} - -/* Given a pointer to a BLOCK node, save a pointer to the most recently - generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given - BLOCK node. */ - -void -remember_end_note (block) - register tree block; -{ - BLOCK_END_NOTE (block) = last_block_end_note; - last_block_end_note = NULL_RTX; -} - -/* Generate RTL code to terminate a binding contour. - VARS is the chain of VAR_DECL nodes - for the variables bound in this contour. - MARK_ENDS is nonzero if we should put a note at the beginning - and end of this binding contour. - - DONT_JUMP_IN is nonzero if it is not valid to jump into this contour. - (That is true automatically if the contour has a saved stack level.) */ - -void -expand_end_bindings (vars, mark_ends, dont_jump_in) - tree vars; - int mark_ends; - int dont_jump_in; -{ - register struct nesting *thisblock = block_stack; - register tree decl; - - if (warn_unused) - for (decl = vars; decl; decl = TREE_CHAIN (decl)) - if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL - && ! DECL_IN_SYSTEM_HEADER (decl)) - warning_with_decl (decl, "unused variable `%s'"); - - if (thisblock->exit_label) - { - do_pending_stack_adjust (); - emit_label (thisblock->exit_label); - } - - /* If necessary, make a handler for nonlocal gotos taking - place in the function calls in this block. */ - if (function_call_count != thisblock->data.block.function_call_count - && nonlocal_labels - /* Make handler for outermost block - if there were any nonlocal gotos to this function. */ - && (thisblock->next == 0 ? current_function_has_nonlocal_label - /* Make handler for inner block if it has something - special to do when you jump out of it. */ - : (thisblock->data.block.cleanups != 0 - || thisblock->data.block.stack_level != 0))) - { - tree link; - rtx afterward = gen_label_rtx (); - rtx handler_label = gen_label_rtx (); - rtx save_receiver = gen_reg_rtx (Pmode); - - /* Don't let jump_optimize delete the handler. */ - LABEL_PRESERVE_P (handler_label) = 1; - - /* Record the handler address in the stack slot for that purpose, - during this block, saving and restoring the outer value. */ - if (thisblock->next != 0) - { - emit_move_insn (nonlocal_goto_handler_slot, save_receiver); - emit_insn_before (gen_move_insn (save_receiver, - nonlocal_goto_handler_slot), - thisblock->data.block.first_insn); - } - emit_insn_before (gen_move_insn (nonlocal_goto_handler_slot, - gen_rtx (LABEL_REF, Pmode, - handler_label)), - thisblock->data.block.first_insn); - - /* Jump around the handler; it runs only when specially invoked. */ - emit_jump (afterward); - emit_label (handler_label); - -#ifdef HAVE_nonlocal_goto - if (! HAVE_nonlocal_goto) -#endif - /* First adjust our frame pointer to its actual value. It was - previously set to the start of the virtual area corresponding to - the stacked variables when we branched here and now needs to be - adjusted to the actual hardware fp value. - - Assignments are to virtual registers are converted by - instantiate_virtual_regs into the corresponding assignment - to the underlying register (fp in this case) that makes - the original assignment true. - So the following insn will actually be - decrementing fp by STARTING_FRAME_OFFSET. */ - emit_move_insn (virtual_stack_vars_rtx, frame_pointer_rtx); - -#if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM - if (fixed_regs[ARG_POINTER_REGNUM]) - { -#ifdef ELIMINABLE_REGS - /* If the argument pointer can be eliminated in favor of the - frame pointer, we don't need to restore it. We assume here - that if such an elimination is present, it can always be used. - This is the case on all known machines; if we don't make this - assumption, we do unnecessary saving on many machines. */ - static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS; - int i; - - for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++) - if (elim_regs[i].from == ARG_POINTER_REGNUM - && elim_regs[i].to == FRAME_POINTER_REGNUM) - break; - - if (i == sizeof elim_regs / sizeof elim_regs [0]) -#endif - { - /* Now restore our arg pointer from the address at which it - was saved in our stack frame. - If there hasn't be space allocated for it yet, make - some now. */ - if (arg_pointer_save_area == 0) - arg_pointer_save_area - = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0); - emit_move_insn (virtual_incoming_args_rtx, - /* We need a pseudo here, or else - instantiate_virtual_regs_1 complains. */ - copy_to_reg (arg_pointer_save_area)); - } - } -#endif - - /* The handler expects the desired label address in the static chain - register. It tests the address and does an appropriate jump - to whatever label is desired. */ - for (link = nonlocal_labels; link; link = TREE_CHAIN (link)) - /* Skip any labels we shouldn't be able to jump to from here. */ - if (! DECL_TOO_LATE (TREE_VALUE (link))) - { - rtx not_this = gen_label_rtx (); - rtx this = gen_label_rtx (); - do_jump_if_equal (static_chain_rtx, - gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))), - this, 0); - emit_jump (not_this); - emit_label (this); - expand_goto (TREE_VALUE (link)); - emit_label (not_this); - } - /* If label is not recognized, abort. */ - emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0, - VOIDmode, 0); - emit_label (afterward); - } - - /* Don't allow jumping into a block that has cleanups or a stack level. */ - if (dont_jump_in - || thisblock->data.block.stack_level != 0 - || thisblock->data.block.cleanups != 0) - { - struct label_chain *chain; - - /* Any labels in this block are no longer valid to go to. - Mark them to cause an error message. */ - for (chain = thisblock->data.block.label_chain; chain; chain = chain->next) - { - DECL_TOO_LATE (chain->label) = 1; - /* If any goto without a fixup came to this label, - that must be an error, because gotos without fixups - come from outside all saved stack-levels and all cleanups. */ - if (TREE_ADDRESSABLE (chain->label)) - error_with_decl (chain->label, - "label `%s' used before containing binding contour"); - } - } - - /* Restore stack level in effect before the block - (only if variable-size objects allocated). */ - /* Perform any cleanups associated with the block. */ - - if (thisblock->data.block.stack_level != 0 - || thisblock->data.block.cleanups != 0) - { - /* Don't let cleanups affect ({...}) constructs. */ - int old_expr_stmts_for_value = expr_stmts_for_value; - rtx old_last_expr_value = last_expr_value; - tree old_last_expr_type = last_expr_type; - expr_stmts_for_value = 0; - - /* Do the cleanups. */ - expand_cleanups (thisblock->data.block.cleanups, NULL_TREE); - do_pending_stack_adjust (); - - expr_stmts_for_value = old_expr_stmts_for_value; - last_expr_value = old_last_expr_value; - last_expr_type = old_last_expr_type; - - /* Restore the stack level. */ - - if (thisblock->data.block.stack_level != 0) - { - emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION, - thisblock->data.block.stack_level, NULL_RTX); - if (nonlocal_goto_handler_slot != 0) - emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, - NULL_RTX); - } - - /* Any gotos out of this block must also do these things. - Also report any gotos with fixups that came to labels in this - level. */ - fixup_gotos (thisblock, - thisblock->data.block.stack_level, - thisblock->data.block.cleanups, - thisblock->data.block.first_insn, - dont_jump_in); - } - - /* Mark the beginning and end of the scope if requested. - We do this now, after running cleanups on the variables - just going out of scope, so they are in scope for their cleanups. */ - - if (mark_ends) - last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END); - else - /* Get rid of the beginning-mark if we don't make an end-mark. */ - NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED; - - /* If doing stupid register allocation, make sure lives of all - register variables declared here extend thru end of scope. */ - - if (obey_regdecls) - for (decl = vars; decl; decl = TREE_CHAIN (decl)) - { - rtx rtl = DECL_RTL (decl); - if (TREE_CODE (decl) == VAR_DECL && rtl != 0) - use_variable (rtl); - } - - /* Restore block_stack level for containing block. */ - - stack_block_stack = thisblock->data.block.innermost_stack_block; - POPSTACK (block_stack); - - /* Pop the stack slot nesting and free any slots at this level. */ - pop_temp_slots (); -} - -/* Generate RTL for the automatic variable declaration DECL. - (Other kinds of declarations are simply ignored if seen here.) - CLEANUP is an expression to be executed at exit from this binding contour; - for example, in C++, it might call the destructor for this variable. - - If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them - either before or after calling `expand_decl' but before compiling - any subsequent expressions. This is because CLEANUP may be expanded - more than once, on different branches of execution. - For the same reason, CLEANUP may not contain a CALL_EXPR - except as its topmost node--else `preexpand_calls' would get confused. - - If CLEANUP is nonzero and DECL is zero, we record a cleanup - that is not associated with any particular variable. - - There is no special support here for C++ constructors. - They should be handled by the proper code in DECL_INITIAL. */ - -void -expand_decl (decl) - register tree decl; -{ - struct nesting *thisblock = block_stack; - tree type = TREE_TYPE (decl); - - /* Only automatic variables need any expansion done. - Static and external variables, and external functions, - will be handled by `assemble_variable' (called from finish_decl). - TYPE_DECL and CONST_DECL require nothing. - PARM_DECLs are handled in `assign_parms'. */ - - if (TREE_CODE (decl) != VAR_DECL) - return; - if (TREE_STATIC (decl) || DECL_EXTERNAL (decl)) - return; - - /* Create the RTL representation for the variable. */ - - if (type == error_mark_node) - DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx); - else if (DECL_SIZE (decl) == 0) - /* Variable with incomplete type. */ - { - if (DECL_INITIAL (decl) == 0) - /* Error message was already done; now avoid a crash. */ - DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1); - else - /* An initializer is going to decide the size of this array. - Until we know the size, represent its address with a reg. */ - DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode)); - } - else if (DECL_MODE (decl) != BLKmode - /* If -ffloat-store, don't put explicit float vars - into regs. */ - && !(flag_float_store - && TREE_CODE (type) == REAL_TYPE) - && ! TREE_THIS_VOLATILE (decl) - && ! TREE_ADDRESSABLE (decl) - && (DECL_REGISTER (decl) || ! obey_regdecls)) - { - /* Automatic variable that can go in a register. */ - enum machine_mode reg_mode = DECL_MODE (decl); - int unsignedp = TREE_UNSIGNED (type); - - if (TREE_CODE (type) == INTEGER_TYPE || TREE_CODE (type) == ENUMERAL_TYPE - || TREE_CODE (type) == BOOLEAN_TYPE || TREE_CODE (type) == CHAR_TYPE - || TREE_CODE (type) == REAL_TYPE || TREE_CODE (type) == POINTER_TYPE - || TREE_CODE (type) == OFFSET_TYPE) - { - PROMOTE_MODE (reg_mode, unsignedp, type); - } - - DECL_RTL (decl) = gen_reg_rtx (reg_mode); - if (TREE_CODE (type) == POINTER_TYPE) - mark_reg_pointer (DECL_RTL (decl)); - REG_USERVAR_P (DECL_RTL (decl)) = 1; - } - else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST) - { - /* Variable of fixed size that goes on the stack. */ - rtx oldaddr = 0; - rtx addr; - - /* If we previously made RTL for this decl, it must be an array - whose size was determined by the initializer. - The old address was a register; set that register now - to the proper address. */ - if (DECL_RTL (decl) != 0) - { - if (GET_CODE (DECL_RTL (decl)) != MEM - || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG) - abort (); - oldaddr = XEXP (DECL_RTL (decl), 0); - } - - DECL_RTL (decl) - = assign_stack_temp (DECL_MODE (decl), - ((TREE_INT_CST_LOW (DECL_SIZE (decl)) - + BITS_PER_UNIT - 1) - / BITS_PER_UNIT), - 1); - - /* Set alignment we actually gave this decl. */ - DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT - : GET_MODE_BITSIZE (DECL_MODE (decl))); - - if (oldaddr) - { - addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr); - if (addr != oldaddr) - emit_move_insn (oldaddr, addr); - } - - /* If this is a memory ref that contains aggregate components, - mark it as such for cse and loop optimize. */ - MEM_IN_STRUCT_P (DECL_RTL (decl)) - = (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE - || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE - || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE - || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE); -#if 0 - /* If this is in memory because of -ffloat-store, - set the volatile bit, to prevent optimizations from - undoing the effects. */ - if (flag_float_store && TREE_CODE (type) == REAL_TYPE) - MEM_VOLATILE_P (DECL_RTL (decl)) = 1; -#endif - } - else - /* Dynamic-size object: must push space on the stack. */ - { - rtx address, size; - - /* Record the stack pointer on entry to block, if have - not already done so. */ - if (thisblock->data.block.stack_level == 0) - { - do_pending_stack_adjust (); - emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION, - &thisblock->data.block.stack_level, - thisblock->data.block.first_insn); - stack_block_stack = thisblock; - } - - /* Compute the variable's size, in bytes. */ - size = expand_expr (size_binop (CEIL_DIV_EXPR, - DECL_SIZE (decl), - size_int (BITS_PER_UNIT)), - NULL_RTX, VOIDmode, 0); - free_temp_slots (); - - /* This is equivalent to calling alloca. */ - current_function_calls_alloca = 1; - - /* Allocate space on the stack for the variable. */ - address = allocate_dynamic_stack_space (size, NULL_RTX, - DECL_ALIGN (decl)); - - if (nonlocal_goto_handler_slot != 0) - emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX); - - /* Reference the variable indirect through that rtx. */ - DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address); - - /* If this is a memory ref that contains aggregate components, - mark it as such for cse and loop optimize. */ - MEM_IN_STRUCT_P (DECL_RTL (decl)) - = (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE - || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE - || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE - || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE); - - /* Indicate the alignment we actually gave this variable. */ -#ifdef STACK_BOUNDARY - DECL_ALIGN (decl) = STACK_BOUNDARY; -#else - DECL_ALIGN (decl) = BIGGEST_ALIGNMENT; -#endif - } - - if (TREE_THIS_VOLATILE (decl)) - MEM_VOLATILE_P (DECL_RTL (decl)) = 1; -#if 0 /* A variable is not necessarily unchanging - just because it is const. RTX_UNCHANGING_P - means no change in the function, - not merely no change in the variable's scope. - It is correct to set RTX_UNCHANGING_P if the variable's scope - is the whole function. There's no convenient way to test that. */ - if (TREE_READONLY (decl)) - RTX_UNCHANGING_P (DECL_RTL (decl)) = 1; -#endif - - /* If doing stupid register allocation, make sure life of any - register variable starts here, at the start of its scope. */ - - if (obey_regdecls) - use_variable (DECL_RTL (decl)); -} - -/* Emit code to perform the initialization of a declaration DECL. */ - -void -expand_decl_init (decl) - tree decl; -{ - int was_used = TREE_USED (decl); - - if (TREE_STATIC (decl)) - return; - - /* Compute and store the initial value now. */ - - if (DECL_INITIAL (decl) == error_mark_node) - { - enum tree_code code = TREE_CODE (TREE_TYPE (decl)); - if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE - || code == POINTER_TYPE) - expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node), - 0, 0); - emit_queue (); - } - else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST) - { - emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl)); - expand_assignment (decl, DECL_INITIAL (decl), 0, 0); - emit_queue (); - } - - /* Don't let the initialization count as "using" the variable. */ - TREE_USED (decl) = was_used; - - /* Free any temporaries we made while initializing the decl. */ - free_temp_slots (); -} - -/* CLEANUP is an expression to be executed at exit from this binding contour; - for example, in C++, it might call the destructor for this variable. - - If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them - either before or after calling `expand_decl' but before compiling - any subsequent expressions. This is because CLEANUP may be expanded - more than once, on different branches of execution. - For the same reason, CLEANUP may not contain a CALL_EXPR - except as its topmost node--else `preexpand_calls' would get confused. - - If CLEANUP is nonzero and DECL is zero, we record a cleanup - that is not associated with any particular variable. */ - -int -expand_decl_cleanup (decl, cleanup) - tree decl, cleanup; -{ - struct nesting *thisblock = block_stack; - - /* Error if we are not in any block. */ - if (thisblock == 0) - return 0; - - /* Record the cleanup if there is one. */ - - if (cleanup != 0) - { - thisblock->data.block.cleanups - = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups); - /* If this block has a cleanup, it belongs in stack_block_stack. */ - stack_block_stack = thisblock; - } - return 1; -} - -/* DECL is an anonymous union. CLEANUP is a cleanup for DECL. - DECL_ELTS is the list of elements that belong to DECL's type. - In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */ - -void -expand_anon_union_decl (decl, cleanup, decl_elts) - tree decl, cleanup, decl_elts; -{ - struct nesting *thisblock = block_stack; - rtx x; - - expand_decl (decl, cleanup); - x = DECL_RTL (decl); - - while (decl_elts) - { - tree decl_elt = TREE_VALUE (decl_elts); - tree cleanup_elt = TREE_PURPOSE (decl_elts); - enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt)); - - /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we - instead create a new MEM rtx with the proper mode. */ - if (GET_CODE (x) == MEM) - { - if (mode == GET_MODE (x)) - DECL_RTL (decl_elt) = x; - else - { - DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0))); - MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x); - RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x); - } - } - else if (GET_CODE (x) == REG) - { - if (mode == GET_MODE (x)) - DECL_RTL (decl_elt) = x; - else - DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0); - } - else - abort (); - - /* Record the cleanup if there is one. */ - - if (cleanup != 0) - thisblock->data.block.cleanups - = temp_tree_cons (decl_elt, cleanup_elt, - thisblock->data.block.cleanups); - - decl_elts = TREE_CHAIN (decl_elts); - } -} - -/* Expand a list of cleanups LIST. - Elements may be expressions or may be nested lists. - - If DONT_DO is nonnull, then any list-element - whose TREE_PURPOSE matches DONT_DO is omitted. - This is sometimes used to avoid a cleanup associated with - a value that is being returned out of the scope. */ - -static void -expand_cleanups (list, dont_do) - tree list; - tree dont_do; -{ - tree tail; - for (tail = list; tail; tail = TREE_CHAIN (tail)) - if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do) - { - if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST) - expand_cleanups (TREE_VALUE (tail), dont_do); - else - { - /* Cleanups may be run multiple times. For example, - when exiting a binding contour, we expand the - cleanups associated with that contour. When a goto - within that binding contour has a target outside that - contour, it will expand all cleanups from its scope to - the target. Though the cleanups are expanded multiple - times, the control paths are non-overlapping so the - cleanups will not be executed twice. */ - expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0); - free_temp_slots (); - } - } -} - -/* Move all cleanups from the current block_stack - to the containing block_stack, where they are assumed to - have been created. If anything can cause a temporary to - be created, but not expanded for more than one level of - block_stacks, then this code will have to change. */ - -void -move_cleanups_up () -{ - struct nesting *block = block_stack; - struct nesting *outer = block->next; - - outer->data.block.cleanups - = chainon (block->data.block.cleanups, - outer->data.block.cleanups); - block->data.block.cleanups = 0; -} - -tree -last_cleanup_this_contour () -{ - if (block_stack == 0) - return 0; - - return block_stack->data.block.cleanups; -} - -/* Return 1 if there are any pending cleanups at this point. - If THIS_CONTOUR is nonzero, check the current contour as well. - Otherwise, look only at the contours that enclose this one. */ - -int -any_pending_cleanups (this_contour) - int this_contour; -{ - struct nesting *block; - - if (block_stack == 0) - return 0; - - if (this_contour && block_stack->data.block.cleanups != NULL) - return 1; - if (block_stack->data.block.cleanups == 0 - && (block_stack->data.block.outer_cleanups == 0 -#if 0 - || block_stack->data.block.outer_cleanups == empty_cleanup_list -#endif - )) - return 0; - - for (block = block_stack->next; block; block = block->next) - if (block->data.block.cleanups != 0) - return 1; - - return 0; -} - -/* Enter a case (Pascal) or switch (C) statement. - Push a block onto case_stack and nesting_stack - to accumulate the case-labels that are seen - and to record the labels generated for the statement. - - EXIT_FLAG is nonzero if `exit_something' should exit this case stmt. - Otherwise, this construct is transparent for `exit_something'. - - EXPR is the index-expression to be dispatched on. - TYPE is its nominal type. We could simply convert EXPR to this type, - but instead we take short cuts. */ - -void -expand_start_case (exit_flag, expr, type, printname) - int exit_flag; - tree expr; - tree type; - char *printname; -{ - register struct nesting *thiscase = ALLOC_NESTING (); - - /* Make an entry on case_stack for the case we are entering. */ - - thiscase->next = case_stack; - thiscase->all = nesting_stack; - thiscase->depth = ++nesting_depth; - thiscase->exit_label = exit_flag ? gen_label_rtx () : 0; - thiscase->data.case_stmt.case_list = 0; - thiscase->data.case_stmt.index_expr = expr; - thiscase->data.case_stmt.nominal_type = type; - thiscase->data.case_stmt.default_label = 0; - thiscase->data.case_stmt.num_ranges = 0; - thiscase->data.case_stmt.printname = printname; - thiscase->data.case_stmt.seenlabel = 0; - case_stack = thiscase; - nesting_stack = thiscase; - - do_pending_stack_adjust (); - - /* Make sure case_stmt.start points to something that won't - need any transformation before expand_end_case. */ - if (GET_CODE (get_last_insn ()) != NOTE) - emit_note (NULL_PTR, NOTE_INSN_DELETED); - - thiscase->data.case_stmt.start = get_last_insn (); -} - -/* Start a "dummy case statement" within which case labels are invalid - and are not connected to any larger real case statement. - This can be used if you don't want to let a case statement jump - into the middle of certain kinds of constructs. */ - -void -expand_start_case_dummy () -{ - register struct nesting *thiscase = ALLOC_NESTING (); - - /* Make an entry on case_stack for the dummy. */ - - thiscase->next = case_stack; - thiscase->all = nesting_stack; - thiscase->depth = ++nesting_depth; - thiscase->exit_label = 0; - thiscase->data.case_stmt.case_list = 0; - thiscase->data.case_stmt.start = 0; - thiscase->data.case_stmt.nominal_type = 0; - thiscase->data.case_stmt.default_label = 0; - thiscase->data.case_stmt.num_ranges = 0; - case_stack = thiscase; - nesting_stack = thiscase; -} - -/* End a dummy case statement. */ - -void -expand_end_case_dummy () -{ - POPSTACK (case_stack); -} - -/* Return the data type of the index-expression - of the innermost case statement, or null if none. */ - -tree -case_index_expr_type () -{ - if (case_stack) - return TREE_TYPE (case_stack->data.case_stmt.index_expr); - return 0; -} - -/* Accumulate one case or default label inside a case or switch statement. - VALUE is the value of the case (a null pointer, for a default label). - - If not currently inside a case or switch statement, return 1 and do - nothing. The caller will print a language-specific error message. - If VALUE is a duplicate or overlaps, return 2 and do nothing - except store the (first) duplicate node in *DUPLICATE. - If VALUE is out of range, return 3 and do nothing. - If we are jumping into the scope of a cleaup or var-sized array, return 5. - Return 0 on success. - - Extended to handle range statements. */ - -int -pushcase (value, label, duplicate) - register tree value; - register tree label; - tree *duplicate; -{ - register struct case_node **l; - register struct case_node *n; - tree index_type; - tree nominal_type; - - /* Fail if not inside a real case statement. */ - if (! (case_stack && case_stack->data.case_stmt.start)) - return 1; - - if (stack_block_stack - && stack_block_stack->depth > case_stack->depth) - return 5; - - index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr); - nominal_type = case_stack->data.case_stmt.nominal_type; - - /* If the index is erroneous, avoid more problems: pretend to succeed. */ - if (index_type == error_mark_node) - return 0; - - /* Convert VALUE to the type in which the comparisons are nominally done. */ - if (value != 0) - value = convert (nominal_type, value); - - /* If this is the first label, warn if any insns have been emitted. */ - if (case_stack->data.case_stmt.seenlabel == 0) - { - rtx insn; - for (insn = case_stack->data.case_stmt.start; - insn; - insn = NEXT_INSN (insn)) - { - if (GET_CODE (insn) == CODE_LABEL) - break; - if (GET_CODE (insn) != NOTE - && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE)) - { - warning ("unreachable code at beginning of %s", - case_stack->data.case_stmt.printname); - break; - } - } - } - case_stack->data.case_stmt.seenlabel = 1; - - /* Fail if this value is out of range for the actual type of the index - (which may be narrower than NOMINAL_TYPE). */ - if (value != 0 && ! int_fits_type_p (value, index_type)) - return 3; - - /* Fail if this is a duplicate or overlaps another entry. */ - if (value == 0) - { - if (case_stack->data.case_stmt.default_label != 0) - { - *duplicate = case_stack->data.case_stmt.default_label; - return 2; - } - case_stack->data.case_stmt.default_label = label; - } - else - { - /* Find the elt in the chain before which to insert the new value, - to keep the chain sorted in increasing order. - But report an error if this element is a duplicate. */ - for (l = &case_stack->data.case_stmt.case_list; - /* Keep going past elements distinctly less than VALUE. */ - *l != 0 && tree_int_cst_lt ((*l)->high, value); - l = &(*l)->right) - ; - if (*l) - { - /* Element we will insert before must be distinctly greater; - overlap means error. */ - if (! tree_int_cst_lt (value, (*l)->low)) - { - *duplicate = (*l)->code_label; - return 2; - } - } - - /* Add this label to the chain, and succeed. - Copy VALUE so it is on temporary rather than momentary - obstack and will thus survive till the end of the case statement. */ - n = (struct case_node *) oballoc (sizeof (struct case_node)); - n->left = 0; - n->right = *l; - n->high = n->low = copy_node (value); - n->code_label = label; - *l = n; - } - - expand_label (label); - return 0; -} - -/* Like pushcase but this case applies to all values - between VALUE1 and VALUE2 (inclusive). - The return value is the same as that of pushcase - but there is one additional error code: - 4 means the specified range was empty. */ - -int -pushcase_range (value1, value2, label, duplicate) - register tree value1, value2; - register tree label; - tree *duplicate; -{ - register struct case_node **l; - register struct case_node *n; - tree index_type; - tree nominal_type; - - /* Fail if not inside a real case statement. */ - if (! (case_stack && case_stack->data.case_stmt.start)) - return 1; - - if (stack_block_stack - && stack_block_stack->depth > case_stack->depth) - return 5; - - index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr); - nominal_type = case_stack->data.case_stmt.nominal_type; - - /* If the index is erroneous, avoid more problems: pretend to succeed. */ - if (index_type == error_mark_node) - return 0; - - /* If this is the first label, warn if any insns have been emitted. */ - if (case_stack->data.case_stmt.seenlabel == 0) - { - rtx insn; - for (insn = case_stack->data.case_stmt.start; - insn; - insn = NEXT_INSN (insn)) - { - if (GET_CODE (insn) == CODE_LABEL) - break; - if (GET_CODE (insn) != NOTE - && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE)) - { - warning ("unreachable code at beginning of %s", - case_stack->data.case_stmt.printname); - break; - } - } - } - case_stack->data.case_stmt.seenlabel = 1; - - /* Convert VALUEs to type in which the comparisons are nominally done. */ - if (value1 == 0) /* Negative infinity. */ - value1 = TYPE_MIN_VALUE(index_type); - value1 = convert (nominal_type, value1); - - if (value2 == 0) /* Positive infinity. */ - value2 = TYPE_MAX_VALUE(index_type); - value2 = convert (nominal_type, value2); - - /* Fail if these values are out of range. */ - if (! int_fits_type_p (value1, index_type)) - return 3; - - if (! int_fits_type_p (value2, index_type)) - return 3; - - /* Fail if the range is empty. */ - if (tree_int_cst_lt (value2, value1)) - return 4; - - /* If the bounds are equal, turn this into the one-value case. */ - if (tree_int_cst_equal (value1, value2)) - return pushcase (value1, label, duplicate); - - /* Find the elt in the chain before which to insert the new value, - to keep the chain sorted in increasing order. - But report an error if this element is a duplicate. */ - for (l = &case_stack->data.case_stmt.case_list; - /* Keep going past elements distinctly less than this range. */ - *l != 0 && tree_int_cst_lt ((*l)->high, value1); - l = &(*l)->right) - ; - if (*l) - { - /* Element we will insert before must be distinctly greater; - overlap means error. */ - if (! tree_int_cst_lt (value2, (*l)->low)) - { - *duplicate = (*l)->code_label; - return 2; - } - } - - /* Add this label to the chain, and succeed. - Copy VALUE1, VALUE2 so they are on temporary rather than momentary - obstack and will thus survive till the end of the case statement. */ - - n = (struct case_node *) oballoc (sizeof (struct case_node)); - n->left = 0; - n->right = *l; - n->low = copy_node (value1); - n->high = copy_node (value2); - n->code_label = label; - *l = n; - - expand_label (label); - - case_stack->data.case_stmt.num_ranges++; - - return 0; -} - -/* Called when the index of a switch statement is an enumerated type - and there is no default label. - - Checks that all enumeration literals are covered by the case - expressions of a switch. Also, warn if there are any extra - switch cases that are *not* elements of the enumerated type. - - If all enumeration literals were covered by the case expressions, - turn one of the expressions into the default expression since it should - not be possible to fall through such a switch. */ - -void -check_for_full_enumeration_handling (type) - tree type; -{ - register struct case_node *n; - register struct case_node **l; - register tree chain; - int all_values = 1; - - /* The time complexity of this loop is currently O(N * M), with - N being the number of members in the enumerated type, and - M being the number of case expressions in the switch. */ - - for (chain = TYPE_VALUES (type); - chain; - chain = TREE_CHAIN (chain)) - { - /* Find a match between enumeral and case expression, if possible. - Quit looking when we've gone too far (since case expressions - are kept sorted in ascending order). Warn about enumerators not - handled in the switch statement case expression list. */ - - for (n = case_stack->data.case_stmt.case_list; - n && tree_int_cst_lt (n->high, TREE_VALUE (chain)); - n = n->right) - ; - - if (!n || tree_int_cst_lt (TREE_VALUE (chain), n->low)) - { - if (warn_switch) - warning ("enumeration value `%s' not handled in switch", - IDENTIFIER_POINTER (TREE_PURPOSE (chain))); - all_values = 0; - } - } - - /* Now we go the other way around; we warn if there are case - expressions that don't correspond to enumerators. This can - occur since C and C++ don't enforce type-checking of - assignments to enumeration variables. */ - - if (warn_switch) - for (n = case_stack->data.case_stmt.case_list; n; n = n->right) - { - for (chain = TYPE_VALUES (type); - chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain)); - chain = TREE_CHAIN (chain)) - ; - - if (!chain) - { - if (TYPE_NAME (type) == 0) - warning ("case value `%d' not in enumerated type", - TREE_INT_CST_LOW (n->low)); - else - warning ("case value `%d' not in enumerated type `%s'", - TREE_INT_CST_LOW (n->low), - IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type)) - == IDENTIFIER_NODE) - ? TYPE_NAME (type) - : DECL_NAME (TYPE_NAME (type)))); - } - if (!tree_int_cst_equal (n->low, n->high)) - { - for (chain = TYPE_VALUES (type); - chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain)); - chain = TREE_CHAIN (chain)) - ; - - if (!chain) - { - if (TYPE_NAME (type) == 0) - warning ("case value `%d' not in enumerated type", - TREE_INT_CST_LOW (n->high)); - else - warning ("case value `%d' not in enumerated type `%s'", - TREE_INT_CST_LOW (n->high), - IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type)) - == IDENTIFIER_NODE) - ? TYPE_NAME (type) - : DECL_NAME (TYPE_NAME (type)))); - } - } - } - -#if 0 - /* ??? This optimization is disabled because it causes valid programs to - fail. ANSI C does not guarantee that an expression with enum type - will have a value that is the same as one of the enumation literals. */ - - /* If all values were found as case labels, make one of them the default - label. Thus, this switch will never fall through. We arbitrarily pick - the last one to make the default since this is likely the most - efficient choice. */ - - if (all_values) - { - for (l = &case_stack->data.case_stmt.case_list; - (*l)->right != 0; - l = &(*l)->right) - ; - - case_stack->data.case_stmt.default_label = (*l)->code_label; - *l = 0; - } -#endif /* 0 */ -} - -/* Terminate a case (Pascal) or switch (C) statement - in which ORIG_INDEX is the expression to be tested. - Generate the code to test it and jump to the right place. */ - -void -expand_end_case (orig_index) - tree orig_index; -{ - tree minval, maxval, range; - rtx default_label = 0; - register struct case_node *n; - int count; - rtx index; - rtx table_label = gen_label_rtx (); - int ncases; - rtx *labelvec; - register int i; - rtx before_case; - register struct nesting *thiscase = case_stack; - tree index_expr = thiscase->data.case_stmt.index_expr; - int unsignedp = TREE_UNSIGNED (TREE_TYPE (index_expr)); - - do_pending_stack_adjust (); - - /* An ERROR_MARK occurs for various reasons including invalid data type. */ - if (TREE_TYPE (index_expr) != error_mark_node) - { - /* If switch expression was an enumerated type, check that all - enumeration literals are covered by the cases. - No sense trying this if there's a default case, however. */ - - if (!thiscase->data.case_stmt.default_label - && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE - && TREE_CODE (index_expr) != INTEGER_CST) - check_for_full_enumeration_handling (TREE_TYPE (orig_index)); - - /* If this is the first label, warn if any insns have been emitted. */ - if (thiscase->data.case_stmt.seenlabel == 0) - { - rtx insn; - for (insn = get_last_insn (); - insn != case_stack->data.case_stmt.start; - insn = PREV_INSN (insn)) - if (GET_CODE (insn) != NOTE - && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE)) - { - warning ("unreachable code at beginning of %s", - case_stack->data.case_stmt.printname); - break; - } - } - - /* If we don't have a default-label, create one here, - after the body of the switch. */ - if (thiscase->data.case_stmt.default_label == 0) - { - thiscase->data.case_stmt.default_label - = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); - expand_label (thiscase->data.case_stmt.default_label); - } - default_label = label_rtx (thiscase->data.case_stmt.default_label); - - before_case = get_last_insn (); - - /* Simplify the case-list before we count it. */ - group_case_nodes (thiscase->data.case_stmt.case_list); - - /* Get upper and lower bounds of case values. - Also convert all the case values to the index expr's data type. */ - - count = 0; - for (n = thiscase->data.case_stmt.case_list; n; n = n->right) - { - /* Check low and high label values are integers. */ - if (TREE_CODE (n->low) != INTEGER_CST) - abort (); - if (TREE_CODE (n->high) != INTEGER_CST) - abort (); - - n->low = convert (TREE_TYPE (index_expr), n->low); - n->high = convert (TREE_TYPE (index_expr), n->high); - - /* Count the elements and track the largest and smallest - of them (treating them as signed even if they are not). */ - if (count++ == 0) - { - minval = n->low; - maxval = n->high; - } - else - { - if (INT_CST_LT (n->low, minval)) - minval = n->low; - if (INT_CST_LT (maxval, n->high)) - maxval = n->high; - } - /* A range counts double, since it requires two compares. */ - if (! tree_int_cst_equal (n->low, n->high)) - count++; - } - - /* Compute span of values. */ - if (count != 0) - range = fold (build (MINUS_EXPR, TREE_TYPE (index_expr), - maxval, minval)); - - if (count == 0 || TREE_CODE (TREE_TYPE (index_expr)) == ERROR_MARK) - { - expand_expr (index_expr, const0_rtx, VOIDmode, 0); - emit_queue (); - emit_jump (default_label); - } - /* If range of values is much bigger than number of values, - make a sequence of conditional branches instead of a dispatch. - If the switch-index is a constant, do it this way - because we can optimize it. */ - -#ifndef CASE_VALUES_THRESHOLD -#ifdef HAVE_casesi -#define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5) -#else - /* If machine does not have a case insn that compares the - bounds, this means extra overhead for dispatch tables - which raises the threshold for using them. */ -#define CASE_VALUES_THRESHOLD 5 -#endif /* HAVE_casesi */ -#endif /* CASE_VALUES_THRESHOLD */ - - else if (TREE_INT_CST_HIGH (range) != 0 - || count < CASE_VALUES_THRESHOLD - || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range)) - > 10 * count) - || TREE_CODE (index_expr) == INTEGER_CST - /* These will reduce to a constant. */ - || (TREE_CODE (index_expr) == CALL_EXPR - && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR - && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL - && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE) - || (TREE_CODE (index_expr) == COMPOUND_EXPR - && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST)) - { - index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); - - /* If the index is a short or char that we do not have - an insn to handle comparisons directly, convert it to - a full integer now, rather than letting each comparison - generate the conversion. */ - - if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT - && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code - == CODE_FOR_nothing)) - { - enum machine_mode wider_mode; - for (wider_mode = GET_MODE (index); wider_mode != VOIDmode; - wider_mode = GET_MODE_WIDER_MODE (wider_mode)) - if (cmp_optab->handlers[(int) wider_mode].insn_code - != CODE_FOR_nothing) - { - index = convert_to_mode (wider_mode, index, unsignedp); - break; - } - } - - emit_queue (); - do_pending_stack_adjust (); - - index = protect_from_queue (index, 0); - if (GET_CODE (index) == MEM) - index = copy_to_reg (index); - if (GET_CODE (index) == CONST_INT - || TREE_CODE (index_expr) == INTEGER_CST) - { - /* Make a tree node with the proper constant value - if we don't already have one. */ - if (TREE_CODE (index_expr) != INTEGER_CST) - { - index_expr - = build_int_2 (INTVAL (index), - !unsignedp && INTVAL (index) >= 0 ? 0 : -1); - index_expr = convert (TREE_TYPE (index_expr), index_expr); - } - - /* For constant index expressions we need only - issue a unconditional branch to the appropriate - target code. The job of removing any unreachable - code is left to the optimisation phase if the - "-O" option is specified. */ - for (n = thiscase->data.case_stmt.case_list; - n; - n = n->right) - { - if (! tree_int_cst_lt (index_expr, n->low) - && ! tree_int_cst_lt (n->high, index_expr)) - break; - } - if (n) - emit_jump (label_rtx (n->code_label)); - else - emit_jump (default_label); - } - else - { - /* If the index expression is not constant we generate - a binary decision tree to select the appropriate - target code. This is done as follows: - - The list of cases is rearranged into a binary tree, - nearly optimal assuming equal probability for each case. - - The tree is transformed into RTL, eliminating - redundant test conditions at the same time. - - If program flow could reach the end of the - decision tree an unconditional jump to the - default code is emitted. */ - - use_cost_table - = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE - && estimate_case_costs (thiscase->data.case_stmt.case_list)); - balance_case_nodes (&thiscase->data.case_stmt.case_list, - NULL_PTR); - emit_case_nodes (index, thiscase->data.case_stmt.case_list, - default_label, TREE_TYPE (index_expr)); - emit_jump_if_reachable (default_label); - } - } - else - { - int win = 0; -#ifdef HAVE_casesi - if (HAVE_casesi) - { - enum machine_mode index_mode = SImode; - int index_bits = GET_MODE_BITSIZE (index_mode); - - /* Convert the index to SImode. */ - if (GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (index_expr))) - > GET_MODE_BITSIZE (index_mode)) - { - enum machine_mode omode = TYPE_MODE (TREE_TYPE (index_expr)); - rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0); - - /* We must handle the endpoints in the original mode. */ - index_expr = build (MINUS_EXPR, TREE_TYPE (index_expr), - index_expr, minval); - minval = integer_zero_node; - index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); - emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 0, 0); - emit_jump_insn (gen_bltu (default_label)); - /* Now we can safely truncate. */ - index = convert_to_mode (index_mode, index, 0); - } - else - { - if (TYPE_MODE (TREE_TYPE (index_expr)) != index_mode) - index_expr = convert (type_for_size (index_bits, 0), - index_expr); - index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); - } - emit_queue (); - index = protect_from_queue (index, 0); - do_pending_stack_adjust (); - - emit_jump_insn (gen_casesi (index, expand_expr (minval, NULL_RTX, - VOIDmode, 0), - expand_expr (range, NULL_RTX, - VOIDmode, 0), - table_label, default_label)); - win = 1; - } -#endif -#ifdef HAVE_tablejump - if (! win && HAVE_tablejump) - { - index_expr = convert (thiscase->data.case_stmt.nominal_type, - fold (build (MINUS_EXPR, - TREE_TYPE (index_expr), - index_expr, minval))); - index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); - emit_queue (); - index = protect_from_queue (index, 0); - do_pending_stack_adjust (); - - do_tablejump (index, TYPE_MODE (TREE_TYPE (index_expr)), - expand_expr (range, NULL_RTX, VOIDmode, 0), - table_label, default_label); - win = 1; - } -#endif - if (! win) - abort (); - - /* Get table of labels to jump to, in order of case index. */ - - ncases = TREE_INT_CST_LOW (range) + 1; - labelvec = (rtx *) alloca (ncases * sizeof (rtx)); - bzero (labelvec, ncases * sizeof (rtx)); - - for (n = thiscase->data.case_stmt.case_list; n; n = n->right) - { - register HOST_WIDE_INT i - = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (minval); - - while (1) - { - labelvec[i] - = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label)); - if (i + TREE_INT_CST_LOW (minval) - == TREE_INT_CST_LOW (n->high)) - break; - i++; - } - } - - /* Fill in the gaps with the default. */ - for (i = 0; i < ncases; i++) - if (labelvec[i] == 0) - labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label); - - /* Output the table */ - emit_label (table_label); - - /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE - were an expression, instead of an #ifdef/#ifndef. */ - if ( -#ifdef CASE_VECTOR_PC_RELATIVE - 1 || -#endif - flag_pic) - emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE, - gen_rtx (LABEL_REF, Pmode, table_label), - gen_rtvec_v (ncases, labelvec))); - else - emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE, - gen_rtvec_v (ncases, labelvec))); - - /* If the case insn drops through the table, - after the table we must jump to the default-label. - Otherwise record no drop-through after the table. */ -#ifdef CASE_DROPS_THROUGH - emit_jump (default_label); -#else - emit_barrier (); -#endif - } - - before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ()); - reorder_insns (before_case, get_last_insn (), - thiscase->data.case_stmt.start); - } - if (thiscase->exit_label) - emit_label (thiscase->exit_label); - - POPSTACK (case_stack); - - free_temp_slots (); -} - -/* Generate code to jump to LABEL if OP1 and OP2 are equal. */ - -static void -do_jump_if_equal (op1, op2, label, unsignedp) - rtx op1, op2, label; - int unsignedp; -{ - if (GET_CODE (op1) == CONST_INT - && GET_CODE (op2) == CONST_INT) - { - if (INTVAL (op1) == INTVAL (op2)) - emit_jump (label); - } - else - { - enum machine_mode mode = GET_MODE (op1); - if (mode == VOIDmode) - mode = GET_MODE (op2); - emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0); - emit_jump_insn (gen_beq (label)); - } -} - -/* Not all case values are encountered equally. This function - uses a heuristic to weight case labels, in cases where that - looks like a reasonable thing to do. - - Right now, all we try to guess is text, and we establish the - following weights: - - chars above space: 16 - digits: 16 - default: 12 - space, punct: 8 - tab: 4 - newline: 2 - other "\" chars: 1 - remaining chars: 0 - - If we find any cases in the switch that are not either -1 or in the range - of valid ASCII characters, or are control characters other than those - commonly used with "\", don't treat this switch scanning text. - - Return 1 if these nodes are suitable for cost estimation, otherwise - return 0. */ - -static int -estimate_case_costs (node) - case_node_ptr node; -{ - tree min_ascii = build_int_2 (-1, -1); - tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0)); - case_node_ptr n; - int i; - - /* If we haven't already made the cost table, make it now. Note that the - lower bound of the table is -1, not zero. */ - - if (cost_table == NULL) - { - cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1; - bzero (cost_table - 1, 129 * sizeof (short)); - - for (i = 0; i < 128; i++) - { - if (isalnum (i)) - cost_table[i] = 16; - else if (ispunct (i)) - cost_table[i] = 8; - else if (iscntrl (i)) - cost_table[i] = -1; - } - - cost_table[' '] = 8; - cost_table['\t'] = 4; - cost_table['\0'] = 4; - cost_table['\n'] = 2; - cost_table['\f'] = 1; - cost_table['\v'] = 1; - cost_table['\b'] = 1; - } - - /* See if all the case expressions look like text. It is text if the - constant is >= -1 and the highest constant is <= 127. Do all comparisons - as signed arithmetic since we don't want to ever access cost_table with a - value less than -1. Also check that none of the constants in a range - are strange control characters. */ - - for (n = node; n; n = n->right) - { - if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high)) - return 0; - - for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++) - if (cost_table[i] < 0) - return 0; - } - - /* All interesting values are within the range of interesting - ASCII characters. */ - return 1; -} - -/* Scan an ordered list of case nodes - combining those with consecutive values or ranges. - - Eg. three separate entries 1: 2: 3: become one entry 1..3: */ - -static void -group_case_nodes (head) - case_node_ptr head; -{ - case_node_ptr node = head; - - while (node) - { - rtx lb = next_real_insn (label_rtx (node->code_label)); - case_node_ptr np = node; - - /* Try to group the successors of NODE with NODE. */ - while (((np = np->right) != 0) - /* Do they jump to the same place? */ - && next_real_insn (label_rtx (np->code_label)) == lb - /* Are their ranges consecutive? */ - && tree_int_cst_equal (np->low, - fold (build (PLUS_EXPR, - TREE_TYPE (node->high), - node->high, - integer_one_node))) - /* An overflow is not consecutive. */ - && tree_int_cst_lt (node->high, - fold (build (PLUS_EXPR, - TREE_TYPE (node->high), - node->high, - integer_one_node)))) - { - node->high = np->high; - } - /* NP is the first node after NODE which can't be grouped with it. - Delete the nodes in between, and move on to that node. */ - node->right = np; - node = np; - } -} - -/* Take an ordered list of case nodes - and transform them into a near optimal binary tree, - on the assumption that any target code selection value is as - likely as any other. - - The transformation is performed by splitting the ordered - list into two equal sections plus a pivot. The parts are - then attached to the pivot as left and right branches. Each - branch is is then transformed recursively. */ - -static void -balance_case_nodes (head, parent) - case_node_ptr *head; - case_node_ptr parent; -{ - register case_node_ptr np; - - np = *head; - if (np) - { - int cost = 0; - int i = 0; - int ranges = 0; - register case_node_ptr *npp; - case_node_ptr left; - - /* Count the number of entries on branch. Also count the ranges. */ - - while (np) - { - if (!tree_int_cst_equal (np->low, np->high)) - { - ranges++; - if (use_cost_table) - cost += cost_table[TREE_INT_CST_LOW (np->high)]; - } - - if (use_cost_table) - cost += cost_table[TREE_INT_CST_LOW (np->low)]; - - i++; - np = np->right; - } - - if (i > 2) - { - /* Split this list if it is long enough for that to help. */ - npp = head; - left = *npp; - if (use_cost_table) - { - /* Find the place in the list that bisects the list's total cost, - Here I gets half the total cost. */ - int n_moved = 0; - i = (cost + 1) / 2; - while (1) - { - /* Skip nodes while their cost does not reach that amount. */ - if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) - i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)]; - i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)]; - if (i <= 0) - break; - npp = &(*npp)->right; - n_moved += 1; - } - if (n_moved == 0) - { - /* Leave this branch lopsided, but optimize left-hand - side and fill in `parent' fields for right-hand side. */ - np = *head; - np->parent = parent; - balance_case_nodes (&np->left, np); - for (; np->right; np = np->right) - np->right->parent = np; - return; - } - } - /* If there are just three nodes, split at the middle one. */ - else if (i == 3) - npp = &(*npp)->right; - else - { - /* Find the place in the list that bisects the list's total cost, - where ranges count as 2. - Here I gets half the total cost. */ - i = (i + ranges + 1) / 2; - while (1) - { - /* Skip nodes while their cost does not reach that amount. */ - if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) - i--; - i--; - if (i <= 0) - break; - npp = &(*npp)->right; - } - } - *head = np = *npp; - *npp = 0; - np->parent = parent; - np->left = left; - - /* Optimize each of the two split parts. */ - balance_case_nodes (&np->left, np); - balance_case_nodes (&np->right, np); - } - else - { - /* Else leave this branch as one level, - but fill in `parent' fields. */ - np = *head; - np->parent = parent; - for (; np->right; np = np->right) - np->right->parent = np; - } - } -} - -/* Search the parent sections of the case node tree - to see if a test for the lower bound of NODE would be redundant. - INDEX_TYPE is the type of the index expression. - - The instructions to generate the case decision tree are - output in the same order as nodes are processed so it is - known that if a parent node checks the range of the current - node minus one that the current node is bounded at its lower - span. Thus the test would be redundant. */ - -static int -node_has_low_bound (node, index_type) - case_node_ptr node; - tree index_type; -{ - tree low_minus_one; - case_node_ptr pnode; - - /* If the lower bound of this node is the lowest value in the index type, - we need not test it. */ - - if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type))) - return 1; - - /* If this node has a left branch, the value at the left must be less - than that at this node, so it cannot be bounded at the bottom and - we need not bother testing any further. */ - - if (node->left) - return 0; - - low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low), - node->low, integer_one_node)); - - /* If the subtraction above overflowed, we can't verify anything. - Otherwise, look for a parent that tests our value - 1. */ - - if (! tree_int_cst_lt (low_minus_one, node->low)) - return 0; - - for (pnode = node->parent; pnode; pnode = pnode->parent) - if (tree_int_cst_equal (low_minus_one, pnode->high)) - return 1; - - return 0; -} - -/* Search the parent sections of the case node tree - to see if a test for the upper bound of NODE would be redundant. - INDEX_TYPE is the type of the index expression. - - The instructions to generate the case decision tree are - output in the same order as nodes are processed so it is - known that if a parent node checks the range of the current - node plus one that the current node is bounded at its upper - span. Thus the test would be redundant. */ - -static int -node_has_high_bound (node, index_type) - case_node_ptr node; - tree index_type; -{ - tree high_plus_one; - case_node_ptr pnode; - - /* If the upper bound of this node is the highest value in the type - of the index expression, we need not test against it. */ - - if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type))) - return 1; - - /* If this node has a right branch, the value at the right must be greater - than that at this node, so it cannot be bounded at the top and - we need not bother testing any further. */ - - if (node->right) - return 0; - - high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high), - node->high, integer_one_node)); - - /* If the addition above overflowed, we can't verify anything. - Otherwise, look for a parent that tests our value + 1. */ - - if (! tree_int_cst_lt (node->high, high_plus_one)) - return 0; - - for (pnode = node->parent; pnode; pnode = pnode->parent) - if (tree_int_cst_equal (high_plus_one, pnode->low)) - return 1; - - return 0; -} - -/* Search the parent sections of the - case node tree to see if both tests for the upper and lower - bounds of NODE would be redundant. */ - -static int -node_is_bounded (node, index_type) - case_node_ptr node; - tree index_type; -{ - return (node_has_low_bound (node, index_type) - && node_has_high_bound (node, index_type)); -} - -/* Emit an unconditional jump to LABEL unless it would be dead code. */ - -static void -emit_jump_if_reachable (label) - rtx label; -{ - if (GET_CODE (get_last_insn ()) != BARRIER) - emit_jump (label); -} - -/* Emit step-by-step code to select a case for the value of INDEX. - The thus generated decision tree follows the form of the - case-node binary tree NODE, whose nodes represent test conditions. - INDEX_TYPE is the type of the index of the switch. - - Care is taken to prune redundant tests from the decision tree - by detecting any boundary conditions already checked by - emitted rtx. (See node_has_high_bound, node_has_low_bound - and node_is_bounded, above.) - - Where the test conditions can be shown to be redundant we emit - an unconditional jump to the target code. As a further - optimization, the subordinates of a tree node are examined to - check for bounded nodes. In this case conditional and/or - unconditional jumps as a result of the boundary check for the - current node are arranged to target the subordinates associated - code for out of bound conditions on the current node node. - - We can assume that when control reaches the code generated here, - the index value has already been compared with the parents - of this node, and determined to be on the same side of each parent - as this node is. Thus, if this node tests for the value 51, - and a parent tested for 52, we don't need to consider - the possibility of a value greater than 51. If another parent - tests for the value 50, then this node need not test anything. */ - -static void -emit_case_nodes (index, node, default_label, index_type) - rtx index; - case_node_ptr node; - rtx default_label; - tree index_type; -{ - /* If INDEX has an unsigned type, we must make unsigned branches. */ - int unsignedp = TREE_UNSIGNED (index_type); - typedef rtx rtx_function (); - rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt; - rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge; - rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt; - rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble; - enum machine_mode mode = GET_MODE (index); - - /* See if our parents have already tested everything for us. - If they have, emit an unconditional jump for this node. */ - if (node_is_bounded (node, index_type)) - emit_jump (label_rtx (node->code_label)); - - else if (tree_int_cst_equal (node->low, node->high)) - { - /* Node is single valued. First see if the index expression matches - this node and then check our children, if any. */ - - do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0), - label_rtx (node->code_label), unsignedp); - - if (node->right != 0 && node->left != 0) - { - /* This node has children on both sides. - Dispatch to one side or the other - by comparing the index value with this node's value. - If one subtree is bounded, check that one first, - so we can avoid real branches in the tree. */ - - if (node_is_bounded (node->right, index_type)) - { - emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - GT, NULL_RTX, mode, unsignedp, 0); - - emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label))); - emit_case_nodes (index, node->left, default_label, index_type); - } - - else if (node_is_bounded (node->left, index_type)) - { - emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - LT, NULL_RTX, mode, unsignedp, 0); - emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label))); - emit_case_nodes (index, node->right, default_label, index_type); - } - - else - { - /* Neither node is bounded. First distinguish the two sides; - then emit the code for one side at a time. */ - - tree test_label - = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); - - /* See if the value is on the right. */ - emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - GT, NULL_RTX, mode, unsignedp, 0); - emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label))); - - /* Value must be on the left. - Handle the left-hand subtree. */ - emit_case_nodes (index, node->left, default_label, index_type); - /* If left-hand subtree does nothing, - go to default. */ - emit_jump_if_reachable (default_label); - - /* Code branches here for the right-hand subtree. */ - expand_label (test_label); - emit_case_nodes (index, node->right, default_label, index_type); - } - } - - else if (node->right != 0 && node->left == 0) - { - /* Here we have a right child but no left so we issue conditional - branch to default and process the right child. - - Omit the conditional branch to default if we it avoid only one - right child; it costs too much space to save so little time. */ - - if (node->right->right || node->right->left - || !tree_int_cst_equal (node->right->low, node->right->high)) - { - if (!node_has_low_bound (node, index_type)) - { - emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - LT, NULL_RTX, mode, unsignedp, 0); - emit_jump_insn ((*gen_blt_pat) (default_label)); - } - - emit_case_nodes (index, node->right, default_label, index_type); - } - else - /* We cannot process node->right normally - since we haven't ruled out the numbers less than - this node's value. So handle node->right explicitly. */ - do_jump_if_equal (index, - expand_expr (node->right->low, NULL_RTX, - VOIDmode, 0), - label_rtx (node->right->code_label), unsignedp); - } - - else if (node->right == 0 && node->left != 0) - { - /* Just one subtree, on the left. */ - -#if 0 /* The following code and comment were formerly part - of the condition here, but they didn't work - and I don't understand what the idea was. -- rms. */ - /* If our "most probable entry" is less probable - than the default label, emit a jump to - the default label using condition codes - already lying around. With no right branch, - a branch-greater-than will get us to the default - label correctly. */ - if (use_cost_table - && cost_table[TREE_INT_CST_LOW (node->high)] < 12) - ; -#endif /* 0 */ - if (node->left->left || node->left->right - || !tree_int_cst_equal (node->left->low, node->left->high)) - { - if (!node_has_high_bound (node, index_type)) - { - emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - GT, NULL_RTX, mode, unsignedp, 0); - emit_jump_insn ((*gen_bgt_pat) (default_label)); - } - - emit_case_nodes (index, node->left, default_label, index_type); - } - else - /* We cannot process node->left normally - since we haven't ruled out the numbers less than - this node's value. So handle node->left explicitly. */ - do_jump_if_equal (index, - expand_expr (node->left->low, NULL_RTX, - VOIDmode, 0), - label_rtx (node->left->code_label), unsignedp); - } - } - else - { - /* Node is a range. These cases are very similar to those for a single - value, except that we do not start by testing whether this node - is the one to branch to. */ - - if (node->right != 0 && node->left != 0) - { - /* Node has subtrees on both sides. - If the right-hand subtree is bounded, - test for it first, since we can go straight there. - Otherwise, we need to make a branch in the control structure, - then handle the two subtrees. */ - tree test_label = 0; - - emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - GT, NULL_RTX, mode, unsignedp, 0); - - if (node_is_bounded (node->right, index_type)) - /* Right hand node is fully bounded so we can eliminate any - testing and branch directly to the target code. */ - emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label))); - else - { - /* Right hand node requires testing. - Branch to a label where we will handle it later. */ - - test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); - emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label))); - } - - /* Value belongs to this node or to the left-hand subtree. */ - - emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0), - GE, NULL_RTX, mode, unsignedp, 0); - emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label))); - - /* Handle the left-hand subtree. */ - emit_case_nodes (index, node->left, default_label, index_type); - - /* If right node had to be handled later, do that now. */ - - if (test_label) - { - /* If the left-hand subtree fell through, - don't let it fall into the right-hand subtree. */ - emit_jump_if_reachable (default_label); - - expand_label (test_label); - emit_case_nodes (index, node->right, default_label, index_type); - } - } - - else if (node->right != 0 && node->left == 0) - { - /* Deal with values to the left of this node, - if they are possible. */ - if (!node_has_low_bound (node, index_type)) - { - emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, - VOIDmode, 0), - LT, NULL_RTX, mode, unsignedp, 0); - emit_jump_insn ((*gen_blt_pat) (default_label)); - } - - /* Value belongs to this node or to the right-hand subtree. */ - - emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - LE, NULL_RTX, mode, unsignedp, 0); - emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label))); - - emit_case_nodes (index, node->right, default_label, index_type); - } - - else if (node->right == 0 && node->left != 0) - { - /* Deal with values to the right of this node, - if they are possible. */ - if (!node_has_high_bound (node, index_type)) - { - emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - GT, NULL_RTX, mode, unsignedp, 0); - emit_jump_insn ((*gen_bgt_pat) (default_label)); - } - - /* Value belongs to this node or to the left-hand subtree. */ - - emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0), - GE, NULL_RTX, mode, unsignedp, 0); - emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label))); - - emit_case_nodes (index, node->left, default_label, index_type); - } - - else - { - /* Node has no children so we check low and high bounds to remove - redundant tests. Only one of the bounds can exist, - since otherwise this node is bounded--a case tested already. */ - - if (!node_has_high_bound (node, index_type)) - { - emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - GT, NULL_RTX, mode, unsignedp, 0); - emit_jump_insn ((*gen_bgt_pat) (default_label)); - } - - if (!node_has_low_bound (node, index_type)) - { - emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, - VOIDmode, 0), - LT, NULL_RTX, mode, unsignedp, 0); - emit_jump_insn ((*gen_blt_pat) (default_label)); - } - - emit_jump (label_rtx (node->code_label)); - } - } -} - -/* These routines are used by the loop unrolling code. They copy BLOCK trees - so that the debugging info will be correct for the unrolled loop. */ - -/* Indexed by block number, contains a pointer to the N'th block node. */ - -static tree *block_vector; - -void -find_loop_tree_blocks () -{ - tree block = DECL_INITIAL (current_function_decl); - - /* There first block is for the function body, and does not have - corresponding block notes. Don't include it in the block vector. */ - block = BLOCK_SUBBLOCKS (block); - - block_vector = identify_blocks (block, get_insns ()); -} - -void -unroll_block_trees () -{ - tree block = DECL_INITIAL (current_function_decl); - - reorder_blocks (block_vector, block, get_insns ()); -} - |