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Diffstat (limited to 'contrib/gcc/reg-stack.c')
| -rw-r--r-- | contrib/gcc/reg-stack.c | 3032 |
1 files changed, 0 insertions, 3032 deletions
diff --git a/contrib/gcc/reg-stack.c b/contrib/gcc/reg-stack.c deleted file mode 100644 index 42caefa0a42b..000000000000 --- a/contrib/gcc/reg-stack.c +++ /dev/null @@ -1,3032 +0,0 @@ -/* Register to Stack convert for GNU compiler. - Copyright (C) 1992, 93-98, 1999 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, 59 Temple Place - Suite 330, -Boston, MA 02111-1307, USA. */ - -/* This pass converts stack-like registers from the "flat register - file" model that gcc uses, to a stack convention that the 387 uses. - - * The form of the input: - - On input, the function consists of insn that have had their - registers fully allocated to a set of "virtual" registers. Note that - the word "virtual" is used differently here than elsewhere in gcc: for - each virtual stack reg, there is a hard reg, but the mapping between - them is not known until this pass is run. On output, hard register - numbers have been substituted, and various pop and exchange insns have - been emitted. The hard register numbers and the virtual register - numbers completely overlap - before this pass, all stack register - numbers are virtual, and afterward they are all hard. - - The virtual registers can be manipulated normally by gcc, and their - semantics are the same as for normal registers. After the hard - register numbers are substituted, the semantics of an insn containing - stack-like regs are not the same as for an insn with normal regs: for - instance, it is not safe to delete an insn that appears to be a no-op - move. In general, no insn containing hard regs should be changed - after this pass is done. - - * The form of the output: - - After this pass, hard register numbers represent the distance from - the current top of stack to the desired register. A reference to - FIRST_STACK_REG references the top of stack, FIRST_STACK_REG + 1, - represents the register just below that, and so forth. Also, REG_DEAD - notes indicate whether or not a stack register should be popped. - - A "swap" insn looks like a parallel of two patterns, where each - pattern is a SET: one sets A to B, the other B to A. - - A "push" or "load" insn is a SET whose SET_DEST is FIRST_STACK_REG - and whose SET_DEST is REG or MEM. Any other SET_DEST, such as PLUS, - will replace the existing stack top, not push a new value. - - A store insn is a SET whose SET_DEST is FIRST_STACK_REG, and whose - SET_SRC is REG or MEM. - - The case where the SET_SRC and SET_DEST are both FIRST_STACK_REG - appears ambiguous. As a special case, the presence of a REG_DEAD note - for FIRST_STACK_REG differentiates between a load insn and a pop. - - If a REG_DEAD is present, the insn represents a "pop" that discards - the top of the register stack. If there is no REG_DEAD note, then the - insn represents a "dup" or a push of the current top of stack onto the - stack. - - * Methodology: - - Existing REG_DEAD and REG_UNUSED notes for stack registers are - deleted and recreated from scratch. REG_DEAD is never created for a - SET_DEST, only REG_UNUSED. - - * asm_operands: - - There are several rules on the usage of stack-like regs in - asm_operands insns. These rules apply only to the operands that are - stack-like regs: - - 1. Given a set of input regs that die in an asm_operands, it is - necessary to know which are implicitly popped by the asm, and - which must be explicitly popped by gcc. - - An input reg that is implicitly popped by the asm must be - explicitly clobbered, unless it is constrained to match an - output operand. - - 2. For any input reg that is implicitly popped by an asm, it is - necessary to know how to adjust the stack to compensate for the pop. - If any non-popped input is closer to the top of the reg-stack than - the implicitly popped reg, it would not be possible to know what the - stack looked like - it's not clear how the rest of the stack "slides - up". - - All implicitly popped input regs must be closer to the top of - the reg-stack than any input that is not implicitly popped. - - 3. It is possible that if an input dies in an insn, reload might - use the input reg for an output reload. Consider this example: - - asm ("foo" : "=t" (a) : "f" (b)); - - This asm says that input B is not popped by the asm, and that - the asm pushes a result onto the reg-stack, ie, the stack is one - deeper after the asm than it was before. But, it is possible that - reload will think that it can use the same reg for both the input and - the output, if input B dies in this insn. - - If any input operand uses the "f" constraint, all output reg - constraints must use the "&" earlyclobber. - - The asm above would be written as - - asm ("foo" : "=&t" (a) : "f" (b)); - - 4. Some operands need to be in particular places on the stack. All - output operands fall in this category - there is no other way to - know which regs the outputs appear in unless the user indicates - this in the constraints. - - Output operands must specifically indicate which reg an output - appears in after an asm. "=f" is not allowed: the operand - constraints must select a class with a single reg. - - 5. Output operands may not be "inserted" between existing stack regs. - Since no 387 opcode uses a read/write operand, all output operands - are dead before the asm_operands, and are pushed by the asm_operands. - It makes no sense to push anywhere but the top of the reg-stack. - - Output operands must start at the top of the reg-stack: output - operands may not "skip" a reg. - - 6. Some asm statements may need extra stack space for internal - calculations. This can be guaranteed by clobbering stack registers - unrelated to the inputs and outputs. - - Here are a couple of reasonable asms to want to write. This asm - takes one input, which is internally popped, and produces two outputs. - - asm ("fsincos" : "=t" (cos), "=u" (sin) : "0" (inp)); - - This asm takes two inputs, which are popped by the fyl2xp1 opcode, - and replaces them with one output. The user must code the "st(1)" - clobber for reg-stack.c to know that fyl2xp1 pops both inputs. - - asm ("fyl2xp1" : "=t" (result) : "0" (x), "u" (y) : "st(1)"); - - */ - -#include "config.h" -#include "system.h" -#include "tree.h" -#include "rtl.h" -#include "insn-config.h" -#include "regs.h" -#include "hard-reg-set.h" -#include "flags.h" -#include "insn-flags.h" -#include "recog.h" -#include "toplev.h" -#include "varray.h" - -#ifdef STACK_REGS - -#define REG_STACK_SIZE (LAST_STACK_REG - FIRST_STACK_REG + 1) - -/* This is the basic stack record. TOP is an index into REG[] such - that REG[TOP] is the top of stack. If TOP is -1 the stack is empty. - - If TOP is -2, REG[] is not yet initialized. Stack initialization - consists of placing each live reg in array `reg' and setting `top' - appropriately. - - REG_SET indicates which registers are live. */ - -typedef struct stack_def -{ - int top; /* index to top stack element */ - HARD_REG_SET reg_set; /* set of live registers */ - char reg[REG_STACK_SIZE]; /* register - stack mapping */ -} *stack; - -/* highest instruction uid */ -static int max_uid = 0; - -/* Number of basic blocks in the current function. */ -static int blocks; - -/* Element N is first insn in basic block N. - This info lasts until we finish compiling the function. */ -static rtx *block_begin; - -/* Element N is last insn in basic block N. - This info lasts until we finish compiling the function. */ -static rtx *block_end; - -/* Element N is nonzero if control can drop into basic block N */ -static char *block_drops_in; - -/* Element N says all about the stack at entry block N */ -static stack block_stack_in; - -/* Element N says all about the stack life at the end of block N */ -static HARD_REG_SET *block_out_reg_set; - -/* This is where the BLOCK_NUM values are really stored. This is set - up by find_blocks and used there and in life_analysis. It can be used - later, but only to look up an insn that is the head or tail of some - block. life_analysis and the stack register conversion process can - add insns within a block. */ -static int *block_number; - -/* We use this array to cache info about insns, because otherwise we - spend too much time in stack_regs_mentioned_p. - - Indexed by insn UIDs. A value of zero is uninitialized, one indicates - the insn uses stack registers, two indicates the insn does not use - stack registers. */ -static varray_type stack_regs_mentioned_data; - -/* This is the register file for all register after conversion */ -static rtx - FP_mode_reg[LAST_STACK_REG+1-FIRST_STACK_REG][(int) MAX_MACHINE_MODE]; - -#define FP_MODE_REG(regno,mode) \ - (FP_mode_reg[(regno)-FIRST_STACK_REG][(int)(mode)]) - -/* Get the basic block number of an insn. See note at block_number - definition are validity of this information. */ - -static int BLOCK_NUM PROTO((rtx)); - -#ifdef __GNUC__ -__inline__ -#endif -static int -BLOCK_NUM(insn) - rtx insn; -{ - int tmp = INSN_UID (insn); - if (tmp > max_uid) - abort (); - tmp = block_number[tmp]; - if (tmp < 0) - abort (); - return tmp; -} - -extern rtx forced_labels; - -/* Forward declarations */ - -static void mark_regs_pat PROTO((rtx, HARD_REG_SET *)); -static void straighten_stack PROTO((rtx, stack)); -static void pop_stack PROTO((stack, int)); -static void record_label_references PROTO((rtx, rtx)); -static rtx *get_true_reg PROTO((rtx *)); - -static void record_asm_reg_life PROTO((rtx, stack)); -static void record_reg_life_pat PROTO((rtx, HARD_REG_SET *, - HARD_REG_SET *, int)); -static int get_asm_operand_n_inputs PROTO((rtx)); -static void record_reg_life PROTO((rtx, int, stack)); -static void find_blocks PROTO((rtx)); -static rtx stack_result PROTO((tree)); -static void stack_reg_life_analysis PROTO((rtx, HARD_REG_SET *)); -static void replace_reg PROTO((rtx *, int)); -static void remove_regno_note PROTO((rtx, enum reg_note, int)); -static int get_hard_regnum PROTO((stack, rtx)); -static void delete_insn_for_stacker PROTO((rtx)); -static rtx emit_pop_insn PROTO((rtx, stack, rtx, rtx (*) ())); -static void emit_swap_insn PROTO((rtx, stack, rtx)); -static void move_for_stack_reg PROTO((rtx, stack, rtx)); -static void swap_rtx_condition PROTO((rtx)); -static void compare_for_stack_reg PROTO((rtx, stack, rtx)); -static void subst_stack_regs_pat PROTO((rtx, stack, rtx)); -static void subst_asm_stack_regs PROTO((rtx, stack)); -static void subst_stack_regs PROTO((rtx, stack)); -static void change_stack PROTO((rtx, stack, stack, rtx (*) ())); - -static void goto_block_pat PROTO((rtx, stack, rtx)); -static void convert_regs PROTO((void)); -static void print_blocks PROTO((FILE *, rtx, rtx)); -static void dump_stack_info PROTO((FILE *)); -static int check_stack_regs_mentioned PROTO((rtx insn)); - -/* Initialize stack_regs_mentioned_data for INSN (growing the virtual array - if needed. Return nonzero if INSN mentions stacked registers. */ - -static int -check_stack_regs_mentioned (insn) - rtx insn; -{ - unsigned int uid = INSN_UID (insn); - if (uid >= VARRAY_SIZE (stack_regs_mentioned_data)) - /* Allocate some extra size to avoid too many reallocs, but - do not grow exponentially. */ - VARRAY_GROW (stack_regs_mentioned_data, uid + uid / 20); - if (stack_regs_mentioned_p (PATTERN (insn))) - { - VARRAY_CHAR (stack_regs_mentioned_data, uid) = 1; - return 1; - } - else - VARRAY_CHAR (stack_regs_mentioned_data, uid) = 2; - return 0; -} - -/* Return nonzero if INSN mentions stacked registers, else return - zero. */ - -int -stack_regs_mentioned (insn) - rtx insn; -{ - unsigned int uid; - if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') - return 0; - uid = INSN_UID (insn); - if (uid >= VARRAY_SIZE (stack_regs_mentioned_data) - || ! VARRAY_CHAR (stack_regs_mentioned_data, uid)) - return (check_stack_regs_mentioned (insn)); - return VARRAY_CHAR (stack_regs_mentioned_data, uid) == 1; -} - - -/* Mark all registers needed for this pattern. */ - -static void -mark_regs_pat (pat, set) - rtx pat; - HARD_REG_SET *set; -{ - enum machine_mode mode; - register int regno; - register int count; - - if (GET_CODE (pat) == SUBREG) - { - mode = GET_MODE (pat); - regno = SUBREG_WORD (pat); - regno += REGNO (SUBREG_REG (pat)); - } - else - regno = REGNO (pat), mode = GET_MODE (pat); - - for (count = HARD_REGNO_NREGS (regno, mode); - count; count--, regno++) - SET_HARD_REG_BIT (*set, regno); -} - -/* Reorganise the stack into ascending numbers, - after this insn. */ - -static void -straighten_stack (insn, regstack) - rtx insn; - stack regstack; -{ - struct stack_def temp_stack; - int top; - - /* If there is only a single register on the stack, then the stack is - already in increasing order and no reorganization is needed. - - Similarly if the stack is empty. */ - if (regstack->top <= 0) - return; - - temp_stack.reg_set = regstack->reg_set; - - for (top = temp_stack.top = regstack->top; top >= 0; top--) - temp_stack.reg[top] = FIRST_STACK_REG + temp_stack.top - top; - - change_stack (insn, regstack, &temp_stack, emit_insn_after); -} - -/* Pop a register from the stack */ - -static void -pop_stack (regstack, regno) - stack regstack; - int regno; -{ - int top = regstack->top; - - CLEAR_HARD_REG_BIT (regstack->reg_set, regno); - regstack->top--; - /* If regno was not at the top of stack then adjust stack */ - if (regstack->reg [top] != regno) - { - int i; - for (i = regstack->top; i >= 0; i--) - if (regstack->reg [i] == regno) - { - int j; - for (j = i; j < top; j++) - regstack->reg [j] = regstack->reg [j + 1]; - break; - } - } -} - -/* Return non-zero if any stack register is mentioned somewhere within PAT. */ - -int -stack_regs_mentioned_p (pat) - rtx pat; -{ - register char *fmt; - register int i; - - if (STACK_REG_P (pat)) - return 1; - - fmt = GET_RTX_FORMAT (GET_CODE (pat)); - for (i = GET_RTX_LENGTH (GET_CODE (pat)) - 1; i >= 0; i--) - { - if (fmt[i] == 'E') - { - register int j; - - for (j = XVECLEN (pat, i) - 1; j >= 0; j--) - if (stack_regs_mentioned_p (XVECEXP (pat, i, j))) - return 1; - } - else if (fmt[i] == 'e' && stack_regs_mentioned_p (XEXP (pat, i))) - return 1; - } - - return 0; -} - -/* Convert register usage from "flat" register file usage to a "stack - register file. FIRST is the first insn in the function, FILE is the - dump file, if used. - - First compute the beginning and end of each basic block. Do a - register life analysis on the stack registers, recording the result - for the head and tail of each basic block. The convert each insn one - by one. Run a last jump_optimize() pass, if optimizing, to eliminate - any cross-jumping created when the converter inserts pop insns.*/ - -void -reg_to_stack (first, file) - rtx first; - FILE *file; -{ - register rtx insn; - register int i; - int stack_reg_seen = 0; - enum machine_mode mode; - HARD_REG_SET stackentry; - - max_uid = get_max_uid (); - VARRAY_CHAR_INIT (stack_regs_mentioned_data, max_uid + 1, - "stack_regs_mentioned cache"); - - CLEAR_HARD_REG_SET (stackentry); - - { - static int initialised; - if (!initialised) - { -#if 0 - initialised = 1; /* This array can not have been previously - initialised, because the rtx's are - thrown away between compilations of - functions. */ -#endif - for (i = FIRST_STACK_REG; i <= LAST_STACK_REG; i++) - { - for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode; - mode = GET_MODE_WIDER_MODE (mode)) - FP_MODE_REG (i, mode) = gen_rtx_REG (mode, i); - for (mode = GET_CLASS_NARROWEST_MODE (MODE_COMPLEX_FLOAT); mode != VOIDmode; - mode = GET_MODE_WIDER_MODE (mode)) - FP_MODE_REG (i, mode) = gen_rtx_REG (mode, i); - } - } - } - - /* Count the basic blocks. Also find maximum insn uid. */ - { - register RTX_CODE prev_code = BARRIER; - register RTX_CODE code; - register int before_function_beg = 1; - - max_uid = 0; - blocks = 0; - for (insn = first; insn; insn = NEXT_INSN (insn)) - { - /* Note that this loop must select the same block boundaries - as code in find_blocks. Also note that this code is not the - same as that used in flow.c. */ - - if (INSN_UID (insn) > max_uid) - max_uid = INSN_UID (insn); - - code = GET_CODE (insn); - - if (code == CODE_LABEL - || (prev_code != INSN - && prev_code != CALL_INSN - && prev_code != CODE_LABEL - && GET_RTX_CLASS (code) == 'i')) - blocks++; - - if (code == NOTE && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG) - before_function_beg = 0; - - /* Remember whether or not this insn mentions an FP regs. - Check JUMP_INSNs too, in case someone creates a funny PARALLEL. */ - - if (GET_RTX_CLASS (code) == 'i' - && stack_regs_mentioned_p (PATTERN (insn))) - { - stack_reg_seen = 1; - VARRAY_CHAR (stack_regs_mentioned_data, INSN_UID (insn)) = 1; - - /* Note any register passing parameters. */ - - if (before_function_beg && code == INSN - && GET_CODE (PATTERN (insn)) == USE) - record_reg_life_pat (PATTERN (insn), (HARD_REG_SET *) 0, - &stackentry, 1); - } - else - VARRAY_CHAR (stack_regs_mentioned_data, INSN_UID (insn)) = 2; - - if (code == CODE_LABEL) - LABEL_REFS (insn) = insn; /* delete old chain */ - - if (code != NOTE) - prev_code = code; - } - } - - /* If no stack register reference exists in this insn, there isn't - anything to convert. */ - - if (! stack_reg_seen) - { - VARRAY_FREE (stack_regs_mentioned_data); - return; - } - - /* If there are stack registers, there must be at least one block. */ - - if (! blocks) - abort (); - - /* Allocate some tables that last till end of compiling this function - and some needed only in find_blocks and life_analysis. */ - - block_begin = (rtx *) alloca (blocks * sizeof (rtx)); - block_end = (rtx *) alloca (blocks * sizeof (rtx)); - block_drops_in = (char *) alloca (blocks); - - block_stack_in = (stack) alloca (blocks * sizeof (struct stack_def)); - block_out_reg_set = (HARD_REG_SET *) alloca (blocks * sizeof (HARD_REG_SET)); - bzero ((char *) block_stack_in, blocks * sizeof (struct stack_def)); - bzero ((char *) block_out_reg_set, blocks * sizeof (HARD_REG_SET)); - - block_number = (int *) alloca ((max_uid + 1) * sizeof (int)); - memset (block_number, -1, (max_uid + 1) * sizeof (int)); - - find_blocks (first); - stack_reg_life_analysis (first, &stackentry); - - /* Dump the life analysis debug information before jump - optimization, as that will destroy the LABEL_REFS we keep the - information in. */ - - if (file) - dump_stack_info (file); - - convert_regs (); - - if (optimize) - jump_optimize (first, 2, 0, 0); - - VARRAY_FREE (stack_regs_mentioned_data); -} - -/* Check PAT, which is in INSN, for LABEL_REFs. Add INSN to the - label's chain of references, and note which insn contains each - reference. */ - -static void -record_label_references (insn, pat) - rtx insn, pat; -{ - register enum rtx_code code = GET_CODE (pat); - register int i; - register char *fmt; - - if (code == LABEL_REF) - { - register rtx label = XEXP (pat, 0); - register rtx ref; - - if (GET_CODE (label) != CODE_LABEL) - abort (); - - /* If this is an undefined label, LABEL_REFS (label) contains - garbage. */ - if (INSN_UID (label) == 0) - return; - - /* Don't make a duplicate in the code_label's chain. */ - - for (ref = LABEL_REFS (label); - ref && ref != label; - ref = LABEL_NEXTREF (ref)) - if (CONTAINING_INSN (ref) == insn) - return; - - CONTAINING_INSN (pat) = insn; - LABEL_NEXTREF (pat) = LABEL_REFS (label); - LABEL_REFS (label) = pat; - - return; - } - - fmt = GET_RTX_FORMAT (code); - for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) - { - if (fmt[i] == 'e') - record_label_references (insn, XEXP (pat, i)); - if (fmt[i] == 'E') - { - register int j; - for (j = 0; j < XVECLEN (pat, i); j++) - record_label_references (insn, XVECEXP (pat, i, j)); - } - } -} - -/* Return a pointer to the REG expression within PAT. If PAT is not a - REG, possible enclosed by a conversion rtx, return the inner part of - PAT that stopped the search. */ - -static rtx * -get_true_reg (pat) - rtx *pat; -{ - for (;;) - switch (GET_CODE (*pat)) - { - case SUBREG: - /* eliminate FP subregister accesses in favour of the - actual FP register in use. */ - { - rtx subreg; - if (FP_REG_P (subreg = SUBREG_REG (*pat))) - { - *pat = FP_MODE_REG (REGNO (subreg) + SUBREG_WORD (*pat), - GET_MODE (subreg)); - default: - return pat; - } - } - case FLOAT: - case FIX: - case FLOAT_EXTEND: - pat = & XEXP (*pat, 0); - } -} - -/* Record the life info of each stack reg in INSN, updating REGSTACK. - N_INPUTS is the number of inputs; N_OUTPUTS the outputs. - OPERANDS is an array of all operands for the insn, and is assumed to - contain all output operands, then all inputs operands. - - There are many rules that an asm statement for stack-like regs must - follow. Those rules are explained at the top of this file: the rule - numbers below refer to that explanation. */ - -static void -record_asm_reg_life (insn, regstack) - rtx insn; - stack regstack; -{ - int i; - int n_clobbers; - int malformed_asm = 0; - rtx body = PATTERN (insn); - - int reg_used_as_output[FIRST_PSEUDO_REGISTER]; - int implicitly_dies[FIRST_PSEUDO_REGISTER]; - int alt; - - rtx *clobber_reg; - int n_inputs, n_outputs; - - /* Find out what the constraints require. If no constraint - alternative matches, this asm is malformed. */ - extract_insn (insn); - constrain_operands (1); - alt = which_alternative; - - preprocess_constraints (); - - n_inputs = get_asm_operand_n_inputs (body); - n_outputs = recog_n_operands - n_inputs; - - if (alt < 0) - { - malformed_asm = 1; - /* Avoid further trouble with this insn. */ - PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx); - VARRAY_CHAR (stack_regs_mentioned_data, INSN_UID (insn)) = 2; - return; - } - - /* Strip SUBREGs here to make the following code simpler. */ - for (i = 0; i < recog_n_operands; i++) - if (GET_CODE (recog_operand[i]) == SUBREG - && GET_CODE (SUBREG_REG (recog_operand[i])) == REG) - recog_operand[i] = SUBREG_REG (recog_operand[i]); - - /* Set up CLOBBER_REG. */ - - n_clobbers = 0; - - if (GET_CODE (body) == PARALLEL) - { - clobber_reg = (rtx *) alloca (XVECLEN (body, 0) * sizeof (rtx)); - - for (i = 0; i < XVECLEN (body, 0); i++) - if (GET_CODE (XVECEXP (body, 0, i)) == CLOBBER) - { - rtx clobber = XVECEXP (body, 0, i); - rtx reg = XEXP (clobber, 0); - - if (GET_CODE (reg) == SUBREG && GET_CODE (SUBREG_REG (reg)) == REG) - reg = SUBREG_REG (reg); - - if (STACK_REG_P (reg)) - { - clobber_reg[n_clobbers] = reg; - n_clobbers++; - } - } - } - - /* Enforce rule #4: Output operands must specifically indicate which - reg an output appears in after an asm. "=f" is not allowed: the - operand constraints must select a class with a single reg. - - Also enforce rule #5: Output operands must start at the top of - the reg-stack: output operands may not "skip" a reg. */ - - bzero ((char *) reg_used_as_output, sizeof (reg_used_as_output)); - for (i = 0; i < n_outputs; i++) - if (STACK_REG_P (recog_operand[i])) - { - if (reg_class_size[(int) recog_op_alt[i][alt].class] != 1) - { - error_for_asm (insn, "Output constraint %d must specify a single register", i); - malformed_asm = 1; - } - else - reg_used_as_output[REGNO (recog_operand[i])] = 1; - } - - - /* Search for first non-popped reg. */ - for (i = FIRST_STACK_REG; i < LAST_STACK_REG + 1; i++) - if (! reg_used_as_output[i]) - break; - - /* If there are any other popped regs, that's an error. */ - for (; i < LAST_STACK_REG + 1; i++) - if (reg_used_as_output[i]) - break; - - if (i != LAST_STACK_REG + 1) - { - error_for_asm (insn, "Output regs must be grouped at top of stack"); - malformed_asm = 1; - } - - /* Enforce rule #2: All implicitly popped input regs must be closer - to the top of the reg-stack than any input that is not implicitly - popped. */ - - bzero ((char *) implicitly_dies, sizeof (implicitly_dies)); - for (i = n_outputs; i < n_outputs + n_inputs; i++) - if (STACK_REG_P (recog_operand[i])) - { - /* An input reg is implicitly popped if it is tied to an - output, or if there is a CLOBBER for it. */ - int j; - - for (j = 0; j < n_clobbers; j++) - if (operands_match_p (clobber_reg[j], recog_operand[i])) - break; - - if (j < n_clobbers || recog_op_alt[i][alt].matches >= 0) - implicitly_dies[REGNO (recog_operand[i])] = 1; - } - - /* Search for first non-popped reg. */ - for (i = FIRST_STACK_REG; i < LAST_STACK_REG + 1; i++) - if (! implicitly_dies[i]) - break; - - /* If there are any other popped regs, that's an error. */ - for (; i < LAST_STACK_REG + 1; i++) - if (implicitly_dies[i]) - break; - - if (i != LAST_STACK_REG + 1) - { - error_for_asm (insn, - "Implicitly popped regs must be grouped at top of stack"); - malformed_asm = 1; - } - - /* Enfore rule #3: If any input operand uses the "f" constraint, all - output constraints must use the "&" earlyclobber. - - ??? Detect this more deterministically by having constraint_asm_operands - record any earlyclobber. */ - - for (i = n_outputs; i < n_outputs + n_inputs; i++) - if (recog_op_alt[i][alt].matches == -1) - { - int j; - - for (j = 0; j < n_outputs; j++) - if (operands_match_p (recog_operand[j], recog_operand[i])) - { - error_for_asm (insn, - "Output operand %d must use `&' constraint", j); - malformed_asm = 1; - } - } - - if (malformed_asm) - { - /* Avoid further trouble with this insn. */ - PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx); - VARRAY_CHAR (stack_regs_mentioned_data, INSN_UID (insn)) = 2; - return; - } - - /* Process all outputs */ - for (i = 0; i < n_outputs; i++) - { - rtx op = recog_operand[i]; - - if (! STACK_REG_P (op)) - { - if (stack_regs_mentioned_p (op)) - abort (); - else - continue; - } - - /* Each destination is dead before this insn. If the - destination is not used after this insn, record this with - REG_UNUSED. */ - - if (! TEST_HARD_REG_BIT (regstack->reg_set, REGNO (op))) - REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_UNUSED, op, - REG_NOTES (insn)); - - CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (op)); - } - - /* Process all inputs */ - for (i = n_outputs; i < n_outputs + n_inputs; i++) - { - rtx op = recog_operand[i]; - if (! STACK_REG_P (op)) - { - if (stack_regs_mentioned_p (op)) - abort (); - else - continue; - } - - /* If an input is dead after the insn, record a death note. - But don't record a death note if there is already a death note, - or if the input is also an output. */ - - if (! TEST_HARD_REG_BIT (regstack->reg_set, REGNO (op)) - && recog_op_alt[i][alt].matches == -1 - && find_regno_note (insn, REG_DEAD, REGNO (op)) == NULL_RTX) - REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_DEAD, op, REG_NOTES (insn)); - - SET_HARD_REG_BIT (regstack->reg_set, REGNO (op)); - } -} - -/* Scan PAT, which is part of INSN, and record registers appearing in - a SET_DEST in DEST, and other registers in SRC. - - This function does not know about SET_DESTs that are both input and - output (such as ZERO_EXTRACT) - this cannot happen on a 387. */ - -static void -record_reg_life_pat (pat, src, dest, douse) - rtx pat; - HARD_REG_SET *src, *dest; - int douse; -{ - register char *fmt; - register int i; - - if (STACK_REG_P (pat) - || (GET_CODE (pat) == SUBREG && STACK_REG_P (SUBREG_REG (pat)))) - { - if (src) - mark_regs_pat (pat, src); - - if (dest) - mark_regs_pat (pat, dest); - - return; - } - - if (GET_CODE (pat) == SET) - { - record_reg_life_pat (XEXP (pat, 0), NULL_PTR, dest, 0); - record_reg_life_pat (XEXP (pat, 1), src, NULL_PTR, 0); - return; - } - - /* We don't need to consider either of these cases. */ - if ((GET_CODE (pat) == USE && !douse) || GET_CODE (pat) == CLOBBER) - return; - - fmt = GET_RTX_FORMAT (GET_CODE (pat)); - for (i = GET_RTX_LENGTH (GET_CODE (pat)) - 1; i >= 0; i--) - { - if (fmt[i] == 'E') - { - register int j; - - for (j = XVECLEN (pat, i) - 1; j >= 0; j--) - record_reg_life_pat (XVECEXP (pat, i, j), src, dest, 0); - } - else if (fmt[i] == 'e') - record_reg_life_pat (XEXP (pat, i), src, dest, 0); - } -} - -/* Calculate the number of inputs and outputs in BODY, an - asm_operands. N_OPERANDS is the total number of operands, and - N_INPUTS and N_OUTPUTS are pointers to ints into which the results are - placed. */ - -static int -get_asm_operand_n_inputs (body) - rtx body; -{ - if (GET_CODE (body) == SET && GET_CODE (SET_SRC (body)) == ASM_OPERANDS) - return ASM_OPERANDS_INPUT_LENGTH (SET_SRC (body)); - - else if (GET_CODE (body) == ASM_OPERANDS) - return ASM_OPERANDS_INPUT_LENGTH (body); - - else if (GET_CODE (body) == PARALLEL - && GET_CODE (XVECEXP (body, 0, 0)) == SET) - return ASM_OPERANDS_INPUT_LENGTH (SET_SRC (XVECEXP (body, 0, 0))); - - else if (GET_CODE (body) == PARALLEL - && GET_CODE (XVECEXP (body, 0, 0)) == ASM_OPERANDS) - return ASM_OPERANDS_INPUT_LENGTH (XVECEXP (body, 0, 0)); - - abort (); -} - -/* Scan INSN, which is in BLOCK, and record the life & death of stack - registers in REGSTACK. This function is called to process insns from - the last insn in a block to the first. The actual scanning is done in - record_reg_life_pat. - - If a register is live after a CALL_INSN, but is not a value return - register for that CALL_INSN, then code is emitted to initialize that - register. The block_end[] data is kept accurate. - - Existing death and unset notes for stack registers are deleted - before processing the insn. */ - -static void -record_reg_life (insn, block, regstack) - rtx insn; - int block; - stack regstack; -{ - rtx note, *note_link; - int n_operands; - - if ((GET_CODE (insn) != INSN && GET_CODE (insn) != CALL_INSN) - || INSN_DELETED_P (insn)) - return; - - /* Strip death notes for stack regs from this insn */ - - note_link = ®_NOTES(insn); - for (note = *note_link; note; note = XEXP (note, 1)) - if (STACK_REG_P (XEXP (note, 0)) - && (REG_NOTE_KIND (note) == REG_DEAD - || REG_NOTE_KIND (note) == REG_UNUSED)) - *note_link = XEXP (note, 1); - else - note_link = &XEXP (note, 1); - - /* Process all patterns in the insn. */ - - n_operands = asm_noperands (PATTERN (insn)); - if (n_operands >= 0) - { - record_asm_reg_life (insn, regstack); - return; - } - - { - HARD_REG_SET src, dest; - int regno; - - CLEAR_HARD_REG_SET (src); - CLEAR_HARD_REG_SET (dest); - - if (GET_CODE (insn) == CALL_INSN) - for (note = CALL_INSN_FUNCTION_USAGE (insn); - note; - note = XEXP (note, 1)) - if (GET_CODE (XEXP (note, 0)) == USE) - record_reg_life_pat (SET_DEST (XEXP (note, 0)), &src, NULL_PTR, 0); - - record_reg_life_pat (PATTERN (insn), &src, &dest, 0); - for (regno = FIRST_STACK_REG; regno <= LAST_STACK_REG; regno++) - if (! TEST_HARD_REG_BIT (regstack->reg_set, regno)) - { - if (TEST_HARD_REG_BIT (src, regno) - && ! TEST_HARD_REG_BIT (dest, regno)) - REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_DEAD, - FP_MODE_REG (regno, DFmode), - REG_NOTES (insn)); - else if (TEST_HARD_REG_BIT (dest, regno)) - REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_UNUSED, - FP_MODE_REG (regno, DFmode), - REG_NOTES (insn)); - } - - if (GET_CODE (insn) == CALL_INSN) - { - int reg; - - /* There might be a reg that is live after a function call. - Initialize it to zero so that the program does not crash. See - comment towards the end of stack_reg_life_analysis(). */ - - for (reg = FIRST_STACK_REG; reg <= LAST_STACK_REG; reg++) - if (! TEST_HARD_REG_BIT (dest, reg) - && TEST_HARD_REG_BIT (regstack->reg_set, reg)) - { - rtx init, pat; - - /* The insn will use virtual register numbers, and so - convert_regs is expected to process these. But BLOCK_NUM - cannot be used on these insns, because they do not appear in - block_number[]. */ - - pat = gen_rtx_SET (VOIDmode, FP_MODE_REG (reg, DFmode), - CONST0_RTX (DFmode)); - init = emit_insn_after (pat, insn); - - CLEAR_HARD_REG_BIT (regstack->reg_set, reg); - - /* If the CALL_INSN was the end of a block, move the - block_end to point to the new insn. */ - - if (block_end[block] == insn) - block_end[block] = init; - } - - /* Some regs do not survive a CALL */ - AND_COMPL_HARD_REG_SET (regstack->reg_set, call_used_reg_set); - } - - AND_COMPL_HARD_REG_SET (regstack->reg_set, dest); - IOR_HARD_REG_SET (regstack->reg_set, src); - } -} - -/* Find all basic blocks of the function, which starts with FIRST. - For each JUMP_INSN, build the chain of LABEL_REFS on each CODE_LABEL. */ - -static void -find_blocks (first) - rtx first; -{ - register rtx insn; - register int block; - register RTX_CODE prev_code = BARRIER; - register RTX_CODE code; - rtx label_value_list = 0; - - /* Record where all the blocks start and end. - Record which basic blocks control can drop in to. */ - - block = -1; - for (insn = first; insn; insn = NEXT_INSN (insn)) - { - /* Note that this loop must select the same block boundaries - as code in reg_to_stack, but that these are not the same - as those selected in flow.c. */ - - code = GET_CODE (insn); - - if (code == CODE_LABEL - || (prev_code != INSN - && prev_code != CALL_INSN - && prev_code != CODE_LABEL - && GET_RTX_CLASS (code) == 'i')) - { - block_begin[++block] = insn; - block_end[block] = insn; - block_drops_in[block] = prev_code != BARRIER; - } - else if (GET_RTX_CLASS (code) == 'i') - block_end[block] = insn; - - if (GET_RTX_CLASS (code) == 'i') - { - rtx note; - - /* Make a list of all labels referred to other than by jumps. */ - for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) - if (REG_NOTE_KIND (note) == REG_LABEL) - label_value_list = gen_rtx_EXPR_LIST (VOIDmode, XEXP (note, 0), - label_value_list); - } - - block_number[INSN_UID (insn)] = block; - - if (code != NOTE) - prev_code = code; - } - - if (block + 1 != blocks) - abort (); - - /* generate all label references to the corresponding jump insn */ - for (block = 0; block < blocks; block++) - { - insn = block_end[block]; - - if (GET_CODE (insn) == JUMP_INSN) - { - rtx pat = PATTERN (insn); - rtx x; - - if (computed_jump_p (insn)) - { - for (x = label_value_list; x; x = XEXP (x, 1)) - record_label_references (insn, - gen_rtx_LABEL_REF (VOIDmode, - XEXP (x, 0))); - - for (x = forced_labels; x; x = XEXP (x, 1)) - record_label_references (insn, - gen_rtx_LABEL_REF (VOIDmode, - XEXP (x, 0))); - } - - record_label_references (insn, pat); - } - } -} - -/* If current function returns its result in an fp stack register, - return the REG. Otherwise, return 0. */ - -static rtx -stack_result (decl) - tree decl; -{ - rtx result; - - /* If the value is supposed to be returned in memory, then clearly - it is not returned in a stack register. */ - if (aggregate_value_p (DECL_RESULT (decl))) - return 0; - - result = DECL_RTL (DECL_RESULT (decl)); - /* ?!? What is this code supposed to do? Can this code actually - trigger if we kick out aggregates above? */ - if (result != 0 - && ! (GET_CODE (result) == REG - && REGNO (result) < FIRST_PSEUDO_REGISTER)) - { -#ifdef FUNCTION_OUTGOING_VALUE - result - = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (decl)), decl); -#else - result = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (decl)), decl); -#endif - } - - return result != 0 && STACK_REG_P (result) ? result : 0; -} - -/* Determine the which registers are live at the start of each basic - block of the function whose first insn is FIRST. - - First, if the function returns a real_type, mark the function - return type as live at each return point, as the RTL may not give any - hint that the register is live. - - Then, start with the last block and work back to the first block. - Similarly, work backwards within each block, insn by insn, recording - which regs are dead and which are used (and therefore live) in the - hard reg set of block_stack_in[]. - - After processing each basic block, if there is a label at the start - of the block, propagate the live registers to all jumps to this block. - - As a special case, if there are regs live in this block, that are - not live in a block containing a jump to this label, and the block - containing the jump has already been processed, we must propagate this - block's entry register life back to the block containing the jump, and - restart life analysis from there. - - In the worst case, this function may traverse the insns - REG_STACK_SIZE times. This is necessary, since a jump towards the end - of the insns may not know that a reg is live at a target that is early - in the insns. So we back up and start over with the new reg live. - - If there are registers that are live at the start of the function, - insns are emitted to initialize these registers. Something similar is - done after CALL_INSNs in record_reg_life. */ - -static void -stack_reg_life_analysis (first, stackentry) - rtx first; - HARD_REG_SET *stackentry; -{ - int reg, block; - struct stack_def regstack; - - { - rtx retvalue; - - if ((retvalue = stack_result (current_function_decl))) - { - /* Find all RETURN insns and mark them. */ - - for (block = blocks - 1; --block >= 0;) - if (GET_CODE (block_end[block]) == JUMP_INSN - && returnjump_p (block_end[block])) - mark_regs_pat (retvalue, block_out_reg_set+block); - - /* Mark off the end of last block if we "fall off" the end of the - function into the epilogue. */ - - if (GET_CODE (block_end[blocks-1]) != JUMP_INSN - || returnjump_p (block_end[blocks-1])) - mark_regs_pat (retvalue, block_out_reg_set+blocks-1); - } - } - - /* now scan all blocks backward for stack register use */ - - block = blocks - 1; - while (block >= 0) - { - register rtx insn, prev; - - /* current register status at last instruction */ - - COPY_HARD_REG_SET (regstack.reg_set, block_out_reg_set[block]); - - prev = block_end[block]; - do - { - insn = prev; - prev = PREV_INSN (insn); - - /* If the insn is a CALL_INSN, we need to ensure that - everything dies. But otherwise don't process unless there - are some stack regs present. */ - - if (stack_regs_mentioned (insn) || GET_CODE (insn) == CALL_INSN) - record_reg_life (insn, block, ®stack); - - } while (insn != block_begin[block]); - - /* Set the state at the start of the block. Mark that no - register mapping information known yet. */ - - COPY_HARD_REG_SET (block_stack_in[block].reg_set, regstack.reg_set); - block_stack_in[block].top = -2; - - /* If there is a label, propagate our register life to all jumps - to this label. */ - - if (GET_CODE (insn) == CODE_LABEL) - { - register rtx label; - int must_restart = 0; - - for (label = LABEL_REFS (insn); label != insn; - label = LABEL_NEXTREF (label)) - { - int jump_block = BLOCK_NUM (CONTAINING_INSN (label)); - - if (jump_block < block) - IOR_HARD_REG_SET (block_out_reg_set[jump_block], - block_stack_in[block].reg_set); - else - { - /* The block containing the jump has already been - processed. If there are registers that were not known - to be live then, but are live now, we must back up - and restart life analysis from that point with the new - life information. */ - - GO_IF_HARD_REG_SUBSET (block_stack_in[block].reg_set, - block_out_reg_set[jump_block], - win); - - IOR_HARD_REG_SET (block_out_reg_set[jump_block], - block_stack_in[block].reg_set); - - block = jump_block; - must_restart = 1; - break; - - win: - ; - } - } - if (must_restart) - continue; - } - - if (block_drops_in[block]) - IOR_HARD_REG_SET (block_out_reg_set[block-1], - block_stack_in[block].reg_set); - - block -= 1; - } - - /* If any reg is live at the start of the first block of a - function, then we must guarantee that the reg holds some value by - generating our own "load" of that register. Otherwise a 387 would - fault trying to access an empty register. */ - - /* Load zero into each live register. The fact that a register - appears live at the function start necessarily implies an error - in the user program: it means that (unless the offending code is *never* - executed) this program is using uninitialised floating point - variables. In order to keep broken code like this happy, we initialise - those variables with zero. - - Note that we are inserting virtual register references here: - these insns must be processed by convert_regs later. Also, these - insns will not be in block_number, so BLOCK_NUM() will fail for them. */ - - for (reg = LAST_STACK_REG; reg >= FIRST_STACK_REG; reg--) - if (TEST_HARD_REG_BIT (block_stack_in[0].reg_set, reg) - && ! TEST_HARD_REG_BIT (*stackentry, reg)) - { - rtx init_rtx; - - init_rtx = gen_rtx_SET (VOIDmode, FP_MODE_REG(reg, DFmode), - CONST0_RTX (DFmode)); - block_begin[0] = emit_insn_after (init_rtx, first); - - CLEAR_HARD_REG_BIT (block_stack_in[0].reg_set, reg); - } -} - -/***************************************************************************** - This section deals with stack register substitution, and forms the second - pass over the RTL. - *****************************************************************************/ - -/* Replace REG, which is a pointer to a stack reg RTX, with an RTX for - the desired hard REGNO. */ - -static void -replace_reg (reg, regno) - rtx *reg; - int regno; -{ - if (regno < FIRST_STACK_REG || regno > LAST_STACK_REG - || ! STACK_REG_P (*reg)) - abort (); - - switch (GET_MODE_CLASS (GET_MODE (*reg))) - { - default: abort (); - case MODE_FLOAT: - case MODE_COMPLEX_FLOAT:; - } - - *reg = FP_MODE_REG (regno, GET_MODE (*reg)); -} - -/* Remove a note of type NOTE, which must be found, for register - number REGNO from INSN. Remove only one such note. */ - -static void -remove_regno_note (insn, note, regno) - rtx insn; - enum reg_note note; - int regno; -{ - register rtx *note_link, this; - - note_link = ®_NOTES(insn); - for (this = *note_link; this; this = XEXP (this, 1)) - if (REG_NOTE_KIND (this) == note - && REG_P (XEXP (this, 0)) && REGNO (XEXP (this, 0)) == regno) - { - *note_link = XEXP (this, 1); - return; - } - else - note_link = &XEXP (this, 1); - - abort (); -} - -/* Find the hard register number of virtual register REG in REGSTACK. - The hard register number is relative to the top of the stack. -1 is - returned if the register is not found. */ - -static int -get_hard_regnum (regstack, reg) - stack regstack; - rtx reg; -{ - int i; - - if (! STACK_REG_P (reg)) - abort (); - - for (i = regstack->top; i >= 0; i--) - if (regstack->reg[i] == REGNO (reg)) - break; - - return i >= 0 ? (FIRST_STACK_REG + regstack->top - i) : -1; -} - -/* Delete INSN from the RTL. Mark the insn, but don't remove it from - the chain of insns. Doing so could confuse block_begin and block_end - if this were the only insn in the block. */ - -static void -delete_insn_for_stacker (insn) - rtx insn; -{ - int i; - - /* Ensure that the side effects were clobbers when deleting a PARALLEL. */ - if (GET_CODE (PATTERN (insn)) == PARALLEL) - for (i = 1; i < XVECLEN (PATTERN (insn), 0); i++) - if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) != CLOBBER) - abort (); - - PUT_CODE (insn, NOTE); - NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; - NOTE_SOURCE_FILE (insn) = 0; -} - -/* Emit an insn to pop virtual register REG before or after INSN. - REGSTACK is the stack state after INSN and is updated to reflect this - pop. WHEN is either emit_insn_before, emit_insn_after or NULL. - in case WHEN is NULL we don't really emit the insn, just modify stack - information. Caller is expected to emit insn himself. - - A pop insn is represented as a SET whose destination is the register to - be popped and source is the top of stack. A death note for the top of stack - cases the movdf pattern to pop. */ - -static rtx -emit_pop_insn (insn, regstack, reg, when) - rtx insn; - stack regstack; - rtx reg; - rtx (*when)(); -{ - rtx pop_insn, pop_rtx; - int hard_regno; - - hard_regno = get_hard_regnum (regstack, reg); - - if (hard_regno < FIRST_STACK_REG) - abort (); - - if (when) - { - pop_rtx = gen_rtx_SET (VOIDmode, FP_MODE_REG (hard_regno, DFmode), - FP_MODE_REG (FIRST_STACK_REG, DFmode)); - - pop_insn = (*when) (pop_rtx, insn); - - REG_NOTES (pop_insn) = gen_rtx_EXPR_LIST (REG_DEAD, - FP_MODE_REG (FIRST_STACK_REG, - DFmode), - REG_NOTES (pop_insn)); - } - - regstack->reg[regstack->top - (hard_regno - FIRST_STACK_REG)] - = regstack->reg[regstack->top]; - regstack->top -= 1; - CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (reg)); - - return pop_insn; -} - -/* Emit an insn before or after INSN to swap virtual register REG with the - top of stack. WHEN should be `emit_insn_before' or `emit_insn_before' - REGSTACK is the stack state before the swap, and is updated to reflect - the swap. A swap insn is represented as a PARALLEL of two patterns: - each pattern moves one reg to the other. - - If REG is already at the top of the stack, no insn is emitted. */ - -static void -emit_swap_insn (insn, regstack, reg) - rtx insn; - stack regstack; - rtx reg; -{ - int hard_regno; - rtx gen_swapdf(); - rtx swap_rtx, swap_insn; - int tmp, other_reg; /* swap regno temps */ - rtx i1; /* the stack-reg insn prior to INSN */ - rtx i1set = NULL_RTX; /* the SET rtx within I1 */ - - hard_regno = get_hard_regnum (regstack, reg); - - if (hard_regno < FIRST_STACK_REG) - abort (); - if (hard_regno == FIRST_STACK_REG) - return; - - other_reg = regstack->top - (hard_regno - FIRST_STACK_REG); - - tmp = regstack->reg[other_reg]; - regstack->reg[other_reg] = regstack->reg[regstack->top]; - regstack->reg[regstack->top] = tmp; - - /* Find the previous insn involving stack regs, but don't go past - any labels, calls or jumps. */ - i1 = prev_nonnote_insn (insn); - while (i1 && GET_CODE (i1) == INSN && !stack_regs_mentioned (i1)) - i1 = prev_nonnote_insn (i1); - - if (i1) - i1set = single_set (i1); - - if (i1set) - { - rtx i1src = *get_true_reg (&SET_SRC (i1set)); - rtx i1dest = *get_true_reg (&SET_DEST (i1set)); - - /* If the previous register stack push was from the reg we are to - swap with, omit the swap. */ - - if (GET_CODE (i1dest) == REG && REGNO (i1dest) == FIRST_STACK_REG - && GET_CODE (i1src) == REG && REGNO (i1src) == hard_regno - 1 - && find_regno_note (i1, REG_DEAD, FIRST_STACK_REG) == NULL_RTX) - return; - - /* If the previous insn wrote to the reg we are to swap with, - omit the swap. */ - - if (GET_CODE (i1dest) == REG && REGNO (i1dest) == hard_regno - && GET_CODE (i1src) == REG && REGNO (i1src) == FIRST_STACK_REG - && find_regno_note (i1, REG_DEAD, FIRST_STACK_REG) == NULL_RTX) - return; - } - - if (GET_RTX_CLASS (GET_CODE (i1)) == 'i' && sets_cc0_p (PATTERN (i1))) - { - i1 = next_nonnote_insn (i1); - if (i1 == insn) - abort (); - } - - swap_rtx = gen_swapdf (FP_MODE_REG (hard_regno, DFmode), - FP_MODE_REG (FIRST_STACK_REG, DFmode)); - swap_insn = emit_insn_after (swap_rtx, i1); -} - -/* Handle a move to or from a stack register in PAT, which is in INSN. - REGSTACK is the current stack. */ - -static void -move_for_stack_reg (insn, regstack, pat) - rtx insn; - stack regstack; - rtx pat; -{ - rtx *psrc = get_true_reg (&SET_SRC (pat)); - rtx *pdest = get_true_reg (&SET_DEST (pat)); - rtx src, dest; - rtx note; - - src = *psrc; dest = *pdest; - - if (STACK_REG_P (src) && STACK_REG_P (dest)) - { - /* Write from one stack reg to another. If SRC dies here, then - just change the register mapping and delete the insn. */ - - note = find_regno_note (insn, REG_DEAD, REGNO (src)); - if (note) - { - int i; - - /* If this is a no-op move, there must not be a REG_DEAD note. */ - if (REGNO (src) == REGNO (dest)) - abort (); - - for (i = regstack->top; i >= 0; i--) - if (regstack->reg[i] == REGNO (src)) - break; - - /* The source must be live, and the dest must be dead. */ - if (i < 0 || get_hard_regnum (regstack, dest) >= FIRST_STACK_REG) - abort (); - - /* It is possible that the dest is unused after this insn. - If so, just pop the src. */ - - if (find_regno_note (insn, REG_UNUSED, REGNO (dest))) - { - emit_pop_insn (insn, regstack, src, emit_insn_after); - - delete_insn_for_stacker (insn); - return; - } - - regstack->reg[i] = REGNO (dest); - - SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest)); - CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (src)); - - delete_insn_for_stacker (insn); - - return; - } - - /* The source reg does not die. */ - - /* If this appears to be a no-op move, delete it, or else it - will confuse the machine description output patterns. But if - it is REG_UNUSED, we must pop the reg now, as per-insn processing - for REG_UNUSED will not work for deleted insns. */ - - if (REGNO (src) == REGNO (dest)) - { - if (find_regno_note (insn, REG_UNUSED, REGNO (dest))) - emit_pop_insn (insn, regstack, dest, emit_insn_after); - - delete_insn_for_stacker (insn); - return; - } - - /* The destination ought to be dead */ - if (get_hard_regnum (regstack, dest) >= FIRST_STACK_REG) - abort (); - - replace_reg (psrc, get_hard_regnum (regstack, src)); - - regstack->reg[++regstack->top] = REGNO (dest); - SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest)); - replace_reg (pdest, FIRST_STACK_REG); - } - else if (STACK_REG_P (src)) - { - /* Save from a stack reg to MEM, or possibly integer reg. Since - only top of stack may be saved, emit an exchange first if - needs be. */ - - emit_swap_insn (insn, regstack, src); - - note = find_regno_note (insn, REG_DEAD, REGNO (src)); - if (note) - { - replace_reg (&XEXP (note, 0), FIRST_STACK_REG); - regstack->top--; - CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (src)); - } - else if (GET_MODE (src) == XFmode && regstack->top < REG_STACK_SIZE - 1) - { - /* A 387 cannot write an XFmode value to a MEM without - clobbering the source reg. The output code can handle - this by reading back the value from the MEM. - But it is more efficient to use a temp register if one is - available. Push the source value here if the register - stack is not full, and then write the value to memory via - a pop. */ - rtx push_rtx, push_insn; - rtx top_stack_reg = FP_MODE_REG (FIRST_STACK_REG, XFmode); - - push_rtx = gen_movxf (top_stack_reg, top_stack_reg); - push_insn = emit_insn_before (push_rtx, insn); - REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_DEAD, top_stack_reg, - REG_NOTES (insn)); - } - - replace_reg (psrc, FIRST_STACK_REG); - } - else if (STACK_REG_P (dest)) - { - /* Load from MEM, or possibly integer REG or constant, into the - stack regs. The actual target is always the top of the - stack. The stack mapping is changed to reflect that DEST is - now at top of stack. */ - - /* The destination ought to be dead */ - if (get_hard_regnum (regstack, dest) >= FIRST_STACK_REG) - abort (); - - if (regstack->top >= REG_STACK_SIZE) - abort (); - - regstack->reg[++regstack->top] = REGNO (dest); - SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest)); - replace_reg (pdest, FIRST_STACK_REG); - } - else - abort (); -} - -static void -swap_rtx_condition (pat) - rtx pat; -{ - register char *fmt; - register int i; - - if (GET_RTX_CLASS (GET_CODE (pat)) == '<') - { - PUT_CODE (pat, swap_condition (GET_CODE (pat))); - return; - } - - fmt = GET_RTX_FORMAT (GET_CODE (pat)); - for (i = GET_RTX_LENGTH (GET_CODE (pat)) - 1; i >= 0; i--) - { - if (fmt[i] == 'E') - { - register int j; - - for (j = XVECLEN (pat, i) - 1; j >= 0; j--) - swap_rtx_condition (XVECEXP (pat, i, j)); - } - else if (fmt[i] == 'e') - swap_rtx_condition (XEXP (pat, i)); - } -} - -/* Handle a comparison. Special care needs to be taken to avoid - causing comparisons that a 387 cannot do correctly, such as EQ. - - Also, a fstp instruction may need to be emitted. The 387 does have an - `fcompp' insn that can pop two regs, but it is sometimes too expensive - to do this - a `fcomp' followed by a `fstpl %st(0)' may be easier to - set up. - - We can not handle this by emiting fpop instruction after compare, because - it appears between cc0 setter and user. So we emit only - REG_DEAD note and handle it as a special case in machine description. - - This code used trick with delay_slot filling to emit pop insn after - comparsion but it didn't worked because it caused confusion with cc_status - in final pass. */ - -static void -compare_for_stack_reg (insn, regstack, pat) - rtx insn; - stack regstack; - rtx pat; -{ - rtx *src1, *src2; - rtx src1_note, src2_note; - rtx cc0_user; - int have_cmove; - int hard_regno; - - src1 = get_true_reg (&XEXP (SET_SRC (pat), 0)); - src2 = get_true_reg (&XEXP (SET_SRC (pat), 1)); - cc0_user = next_cc0_user (insn); - - /* If the insn that uses cc0 is an FP-conditional move, then the destination - must be the top of stack */ - if (GET_CODE (PATTERN (cc0_user)) == SET - && SET_DEST (PATTERN (cc0_user)) != pc_rtx - && GET_CODE (SET_SRC (PATTERN (cc0_user))) == IF_THEN_ELSE - && (GET_MODE_CLASS (GET_MODE (SET_DEST (PATTERN (cc0_user)))) - == MODE_FLOAT)) - { - rtx *dest; - - dest = get_true_reg (&SET_DEST (PATTERN (cc0_user))); - - have_cmove = 1; - if (get_hard_regnum (regstack, *dest) >= FIRST_STACK_REG - && REGNO (*dest) != regstack->reg[regstack->top]) - { - emit_swap_insn (insn, regstack, *dest); - } - } - else - have_cmove = 0; - - /* ??? If fxch turns out to be cheaper than fstp, give priority to - registers that die in this insn - move those to stack top first. */ - if (! STACK_REG_P (*src1) - || (STACK_REG_P (*src2) - && get_hard_regnum (regstack, *src2) == FIRST_STACK_REG)) - { - rtx temp, next; - - temp = XEXP (SET_SRC (pat), 0); - XEXP (SET_SRC (pat), 0) = XEXP (SET_SRC (pat), 1); - XEXP (SET_SRC (pat), 1) = temp; - - src1 = get_true_reg (&XEXP (SET_SRC (pat), 0)); - src2 = get_true_reg (&XEXP (SET_SRC (pat), 1)); - - next = next_cc0_user (insn); - if (next == NULL_RTX) - abort (); - - swap_rtx_condition (PATTERN (next)); - INSN_CODE (next) = -1; - INSN_CODE (insn) = -1; - } - - /* We will fix any death note later. */ - - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - - if (STACK_REG_P (*src2)) - src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2)); - else - src2_note = NULL_RTX; - - if (! have_cmove) - emit_swap_insn (insn, regstack, *src1); - - replace_reg (src1, FIRST_STACK_REG); - - if (STACK_REG_P (*src2)) - { - hard_regno = get_hard_regnum (regstack, *src2); - replace_reg (src2, hard_regno); - } - - if (src1_note) - { - pop_stack (regstack, REGNO (XEXP (src1_note, 0))); - replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG); - } - - /* If the second operand dies, handle that. But if the operands are - the same stack register, don't bother, because only one death is - needed, and it was just handled. */ - - if (src2_note - && ! (STACK_REG_P (*src1) && STACK_REG_P (*src2) - && REGNO (*src1) == REGNO (*src2))) - { - /* As a special case, two regs may die in this insn if src2 is - next to top of stack and the top of stack also dies. Since - we have already popped src1, "next to top of stack" is really - at top (FIRST_STACK_REG) now. */ - - if (get_hard_regnum (regstack, XEXP (src2_note, 0)) == FIRST_STACK_REG - && src1_note) - { - pop_stack (regstack, REGNO (XEXP (src2_note, 0))); - replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG + 1); - } - else - { - /* Pop of second operand is handled using special REG_DEAD note - because we can't emit pop insn after cc0 setter. */ - - emit_pop_insn (insn, regstack, XEXP (src2_note, 0), NULL); - replace_reg (&XEXP (src2_note, 0), hard_regno); - } - } -} - -/* Substitute new registers in PAT, which is part of INSN. REGSTACK - is the current register layout. */ - -static void -subst_stack_regs_pat (insn, regstack, pat) - rtx insn; - stack regstack; - rtx pat; -{ - rtx *dest, *src; - rtx *src1 = (rtx *) NULL_PTR, *src2; - rtx src1_note, src2_note; - - if (GET_CODE (pat) != SET) - return; - - dest = get_true_reg (&SET_DEST (pat)); - src = get_true_reg (&SET_SRC (pat)); - - /* See if this is a `movM' pattern, and handle elsewhere if so. */ - - if (*dest != cc0_rtx - && (STACK_REG_P (*src) - || (STACK_REG_P (*dest) - && (GET_CODE (*src) == REG || GET_CODE (*src) == MEM - || GET_CODE (*src) == CONST_DOUBLE)))) - move_for_stack_reg (insn, regstack, pat); - else - switch (GET_CODE (SET_SRC (pat))) - { - case COMPARE: - compare_for_stack_reg (insn, regstack, pat); - break; - - case CALL: - { - int count; - for (count = HARD_REGNO_NREGS (REGNO (*dest), GET_MODE (*dest)); - --count >= 0;) - { - regstack->reg[++regstack->top] = REGNO (*dest) + count; - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest) + count); - } - } - replace_reg (dest, FIRST_STACK_REG); - break; - - case REG: - /* This is a `tstM2' case. */ - if (*dest != cc0_rtx) - abort (); - - src1 = src; - - /* Fall through. */ - - case FLOAT_TRUNCATE: - case SQRT: - case ABS: - case NEG: - /* These insns only operate on the top of the stack. DEST might - be cc0_rtx if we're processing a tstM pattern. Also, it's - possible that the tstM case results in a REG_DEAD note on the - source. */ - - if (src1 == 0) - src1 = get_true_reg (&XEXP (SET_SRC (pat), 0)); - - emit_swap_insn (insn, regstack, *src1); - - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - - if (STACK_REG_P (*dest)) - replace_reg (dest, FIRST_STACK_REG); - - if (src1_note) - { - replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG); - regstack->top--; - CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (*src1)); - } - - replace_reg (src1, FIRST_STACK_REG); - - break; - - case MINUS: - case DIV: - /* On i386, reversed forms of subM3 and divM3 exist for - MODE_FLOAT, so the same code that works for addM3 and mulM3 - can be used. */ - case MULT: - case PLUS: - /* These insns can accept the top of stack as a destination - from a stack reg or mem, or can use the top of stack as a - source and some other stack register (possibly top of stack) - as a destination. */ - - src1 = get_true_reg (&XEXP (SET_SRC (pat), 0)); - src2 = get_true_reg (&XEXP (SET_SRC (pat), 1)); - - /* We will fix any death note later. */ - - if (STACK_REG_P (*src1)) - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - else - src1_note = NULL_RTX; - if (STACK_REG_P (*src2)) - src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2)); - else - src2_note = NULL_RTX; - - /* If either operand is not a stack register, then the dest - must be top of stack. */ - - if (! STACK_REG_P (*src1) || ! STACK_REG_P (*src2)) - emit_swap_insn (insn, regstack, *dest); - else - { - /* Both operands are REG. If neither operand is already - at the top of stack, choose to make the one that is the dest - the new top of stack. */ - - int src1_hard_regnum, src2_hard_regnum; - - src1_hard_regnum = get_hard_regnum (regstack, *src1); - src2_hard_regnum = get_hard_regnum (regstack, *src2); - if (src1_hard_regnum == -1 || src2_hard_regnum == -1) - abort (); - - if (src1_hard_regnum != FIRST_STACK_REG - && src2_hard_regnum != FIRST_STACK_REG) - emit_swap_insn (insn, regstack, *dest); - } - - if (STACK_REG_P (*src1)) - replace_reg (src1, get_hard_regnum (regstack, *src1)); - if (STACK_REG_P (*src2)) - replace_reg (src2, get_hard_regnum (regstack, *src2)); - - if (src1_note) - { - /* If the register that dies is at the top of stack, then - the destination is somewhere else - merely substitute it. - But if the reg that dies is not at top of stack, then - move the top of stack to the dead reg, as though we had - done the insn and then a store-with-pop. */ - - if (REGNO (XEXP (src1_note, 0)) == regstack->reg[regstack->top]) - { - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, get_hard_regnum (regstack, *dest)); - } - else - { - int regno = get_hard_regnum (regstack, XEXP (src1_note, 0)); - - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, regno); - - regstack->reg[regstack->top - (regno - FIRST_STACK_REG)] - = regstack->reg[regstack->top]; - } - - CLEAR_HARD_REG_BIT (regstack->reg_set, - REGNO (XEXP (src1_note, 0))); - replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG); - regstack->top--; - } - else if (src2_note) - { - if (REGNO (XEXP (src2_note, 0)) == regstack->reg[regstack->top]) - { - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, get_hard_regnum (regstack, *dest)); - } - else - { - int regno = get_hard_regnum (regstack, XEXP (src2_note, 0)); - - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, regno); - - regstack->reg[regstack->top - (regno - FIRST_STACK_REG)] - = regstack->reg[regstack->top]; - } - - CLEAR_HARD_REG_BIT (regstack->reg_set, - REGNO (XEXP (src2_note, 0))); - replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG); - regstack->top--; - } - else - { - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, get_hard_regnum (regstack, *dest)); - } - - break; - - case UNSPEC: - switch (XINT (SET_SRC (pat), 1)) - { - case 1: /* sin */ - case 2: /* cos */ - /* These insns only operate on the top of the stack. */ - - src1 = get_true_reg (&XVECEXP (SET_SRC (pat), 0, 0)); - - emit_swap_insn (insn, regstack, *src1); - - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - - if (STACK_REG_P (*dest)) - replace_reg (dest, FIRST_STACK_REG); - - if (src1_note) - { - replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG); - regstack->top--; - CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (*src1)); - } - - replace_reg (src1, FIRST_STACK_REG); - - break; - - default: - abort (); - } - break; - - case IF_THEN_ELSE: - /* dest has to be on stack. */ - if (get_hard_regnum (regstack, *dest) < FIRST_STACK_REG) - abort (); - - /* This insn requires the top of stack to be the destination. */ - - /* If the comparison operator is an FP comparison operator, - it is handled correctly by compare_for_stack_reg () who - will move the destination to the top of stack. But if the - comparison operator is not an FP comparison operator, we - have to handle it here. */ - if (get_hard_regnum (regstack, *dest) >= FIRST_STACK_REG - && REGNO (*dest) != regstack->reg[regstack->top]) - emit_swap_insn (insn, regstack, *dest); - - src1 = get_true_reg (&XEXP (SET_SRC (pat), 1)); - src2 = get_true_reg (&XEXP (SET_SRC (pat), 2)); - - src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1)); - src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2)); - - { - rtx src_note [3]; - int i; - - src_note[0] = 0; - src_note[1] = src1_note; - src_note[2] = src2_note; - - if (STACK_REG_P (*src1)) - replace_reg (src1, get_hard_regnum (regstack, *src1)); - if (STACK_REG_P (*src2)) - replace_reg (src2, get_hard_regnum (regstack, *src2)); - - for (i = 1; i <= 2; i++) - if (src_note [i]) - { - /* If the register that dies is not at the top of stack, then - move the top of stack to the dead reg */ - if (REGNO (XEXP (src_note[i], 0)) - != regstack->reg[regstack->top]) - { - remove_regno_note (insn, REG_DEAD, - REGNO (XEXP (src_note [i], 0))); - emit_pop_insn (insn, regstack, XEXP (src_note[i], 0), - emit_insn_after); - } - else - { - CLEAR_HARD_REG_BIT (regstack->reg_set, - REGNO (XEXP (src_note[i], 0))); - replace_reg (&XEXP (src_note[i], 0), FIRST_STACK_REG); - regstack->top--; - } - } - } - - /* Make dest the top of stack. */ - SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest)); - replace_reg (dest, FIRST_STACK_REG); - - break; - - default: - abort (); - } -} - -/* Substitute hard regnums for any stack regs in INSN, which has - N_INPUTS inputs and N_OUTPUTS outputs. REGSTACK is the stack info - before the insn, and is updated with changes made here. - - There are several requirements and assumptions about the use of - stack-like regs in asm statements. These rules are enforced by - record_asm_stack_regs; see comments there for details. Any - asm_operands left in the RTL at this point may be assume to meet the - requirements, since record_asm_stack_regs removes any problem asm. */ - -static void -subst_asm_stack_regs (insn, regstack) - rtx insn; - stack regstack; -{ - rtx body = PATTERN (insn); - int alt; - - rtx *note_reg; /* Array of note contents */ - rtx **note_loc; /* Address of REG field of each note */ - enum reg_note *note_kind; /* The type of each note */ - - rtx *clobber_reg; - rtx **clobber_loc; - - struct stack_def temp_stack; - int n_notes; - int n_clobbers; - rtx note; - int i; - int n_inputs, n_outputs; - - /* Find out what the constraints required. If no constraint - alternative matches, that is a compiler bug: we should have caught - such an insn during the life analysis pass (and reload should have - caught it regardless). */ - extract_insn (insn); - constrain_operands (1); - alt = which_alternative; - - preprocess_constraints (); - - n_inputs = get_asm_operand_n_inputs (body); - n_outputs = recog_n_operands - n_inputs; - - if (alt < 0) - abort (); - - /* Strip SUBREGs here to make the following code simpler. */ - for (i = 0; i < recog_n_operands; i++) - if (GET_CODE (recog_operand[i]) == SUBREG - && GET_CODE (SUBREG_REG (recog_operand[i])) == REG) - { - recog_operand_loc[i] = & SUBREG_REG (recog_operand[i]); - recog_operand[i] = SUBREG_REG (recog_operand[i]); - } - - /* Set up NOTE_REG, NOTE_LOC and NOTE_KIND. */ - - for (i = 0, note = REG_NOTES (insn); note; note = XEXP (note, 1)) - i++; - - note_reg = (rtx *) alloca (i * sizeof (rtx)); - note_loc = (rtx **) alloca (i * sizeof (rtx *)); - note_kind = (enum reg_note *) alloca (i * sizeof (enum reg_note)); - - n_notes = 0; - for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) - { - rtx reg = XEXP (note, 0); - rtx *loc = & XEXP (note, 0); - - if (GET_CODE (reg) == SUBREG && GET_CODE (SUBREG_REG (reg)) == REG) - { - loc = & SUBREG_REG (reg); - reg = SUBREG_REG (reg); - } - - if (STACK_REG_P (reg) - && (REG_NOTE_KIND (note) == REG_DEAD - || REG_NOTE_KIND (note) == REG_UNUSED)) - { - note_reg[n_notes] = reg; - note_loc[n_notes] = loc; - note_kind[n_notes] = REG_NOTE_KIND (note); - n_notes++; - } - } - - /* Set up CLOBBER_REG and CLOBBER_LOC. */ - - n_clobbers = 0; - - if (GET_CODE (body) == PARALLEL) - { - clobber_reg = (rtx *) alloca (XVECLEN (body, 0) * sizeof (rtx)); - clobber_loc = (rtx **) alloca (XVECLEN (body, 0) * sizeof (rtx *)); - - for (i = 0; i < XVECLEN (body, 0); i++) - if (GET_CODE (XVECEXP (body, 0, i)) == CLOBBER) - { - rtx clobber = XVECEXP (body, 0, i); - rtx reg = XEXP (clobber, 0); - rtx *loc = & XEXP (clobber, 0); - - if (GET_CODE (reg) == SUBREG && GET_CODE (SUBREG_REG (reg)) == REG) - { - loc = & SUBREG_REG (reg); - reg = SUBREG_REG (reg); - } - - if (STACK_REG_P (reg)) - { - clobber_reg[n_clobbers] = reg; - clobber_loc[n_clobbers] = loc; - n_clobbers++; - } - } - } - - bcopy ((char *) regstack, (char *) &temp_stack, sizeof (temp_stack)); - - /* Put the input regs into the desired place in TEMP_STACK. */ - - for (i = n_outputs; i < n_outputs + n_inputs; i++) - if (STACK_REG_P (recog_operand[i]) - && reg_class_subset_p (recog_op_alt[i][alt].class, - FLOAT_REGS) - && recog_op_alt[i][alt].class != FLOAT_REGS) - { - /* If an operand needs to be in a particular reg in - FLOAT_REGS, the constraint was either 't' or 'u'. Since - these constraints are for single register classes, and reload - guaranteed that operand[i] is already in that class, we can - just use REGNO (recog_operand[i]) to know which actual reg this - operand needs to be in. */ - - int regno = get_hard_regnum (&temp_stack, recog_operand[i]); - - if (regno < 0) - abort (); - - if (regno != REGNO (recog_operand[i])) - { - /* recog_operand[i] is not in the right place. Find it - and swap it with whatever is already in I's place. - K is where recog_operand[i] is now. J is where it should - be. */ - int j, k, temp; - - k = temp_stack.top - (regno - FIRST_STACK_REG); - j = (temp_stack.top - - (REGNO (recog_operand[i]) - FIRST_STACK_REG)); - - temp = temp_stack.reg[k]; - temp_stack.reg[k] = temp_stack.reg[j]; - temp_stack.reg[j] = temp; - } - } - - /* emit insns before INSN to make sure the reg-stack is in the right - order. */ - - change_stack (insn, regstack, &temp_stack, emit_insn_before); - - /* Make the needed input register substitutions. Do death notes and - clobbers too, because these are for inputs, not outputs. */ - - for (i = n_outputs; i < n_outputs + n_inputs; i++) - if (STACK_REG_P (recog_operand[i])) - { - int regnum = get_hard_regnum (regstack, recog_operand[i]); - - if (regnum < 0) - abort (); - - replace_reg (recog_operand_loc[i], regnum); - } - - for (i = 0; i < n_notes; i++) - if (note_kind[i] == REG_DEAD) - { - int regnum = get_hard_regnum (regstack, note_reg[i]); - - if (regnum < 0) - abort (); - - replace_reg (note_loc[i], regnum); - } - - for (i = 0; i < n_clobbers; i++) - { - /* It's OK for a CLOBBER to reference a reg that is not live. - Don't try to replace it in that case. */ - int regnum = get_hard_regnum (regstack, clobber_reg[i]); - - if (regnum >= 0) - { - /* Sigh - clobbers always have QImode. But replace_reg knows - that these regs can't be MODE_INT and will abort. Just put - the right reg there without calling replace_reg. */ - - *clobber_loc[i] = FP_MODE_REG (regnum, DFmode); - } - } - - /* Now remove from REGSTACK any inputs that the asm implicitly popped. */ - - for (i = n_outputs; i < n_outputs + n_inputs; i++) - if (STACK_REG_P (recog_operand[i])) - { - /* An input reg is implicitly popped if it is tied to an - output, or if there is a CLOBBER for it. */ - int j; - - for (j = 0; j < n_clobbers; j++) - if (operands_match_p (clobber_reg[j], recog_operand[i])) - break; - - if (j < n_clobbers || recog_op_alt[i][alt].matches >= 0) - { - /* recog_operand[i] might not be at the top of stack. But that's - OK, because all we need to do is pop the right number of regs - off of the top of the reg-stack. record_asm_stack_regs - guaranteed that all implicitly popped regs were grouped - at the top of the reg-stack. */ - - CLEAR_HARD_REG_BIT (regstack->reg_set, - regstack->reg[regstack->top]); - regstack->top--; - } - } - - /* Now add to REGSTACK any outputs that the asm implicitly pushed. - Note that there isn't any need to substitute register numbers. - ??? Explain why this is true. */ - - for (i = LAST_STACK_REG; i >= FIRST_STACK_REG; i--) - { - /* See if there is an output for this hard reg. */ - int j; - - for (j = 0; j < n_outputs; j++) - if (STACK_REG_P (recog_operand[j]) && REGNO (recog_operand[j]) == i) - { - regstack->reg[++regstack->top] = i; - SET_HARD_REG_BIT (regstack->reg_set, i); - break; - } - } - - /* Now emit a pop insn for any REG_UNUSED output, or any REG_DEAD - input that the asm didn't implicitly pop. If the asm didn't - implicitly pop an input reg, that reg will still be live. - - Note that we can't use find_regno_note here: the register numbers - in the death notes have already been substituted. */ - - for (i = 0; i < n_outputs; i++) - if (STACK_REG_P (recog_operand[i])) - { - int j; - - for (j = 0; j < n_notes; j++) - if (REGNO (recog_operand[i]) == REGNO (note_reg[j]) - && note_kind[j] == REG_UNUSED) - { - insn = emit_pop_insn (insn, regstack, recog_operand[i], - emit_insn_after); - break; - } - } - - for (i = n_outputs; i < n_outputs + n_inputs; i++) - if (STACK_REG_P (recog_operand[i])) - { - int j; - - for (j = 0; j < n_notes; j++) - if (REGNO (recog_operand[i]) == REGNO (note_reg[j]) - && note_kind[j] == REG_DEAD - && TEST_HARD_REG_BIT (regstack->reg_set, - REGNO (recog_operand[i]))) - { - insn = emit_pop_insn (insn, regstack, recog_operand[i], - emit_insn_after); - break; - } - } -} - -/* Substitute stack hard reg numbers for stack virtual registers in - INSN. Non-stack register numbers are not changed. REGSTACK is the - current stack content. Insns may be emitted as needed to arrange the - stack for the 387 based on the contents of the insn. */ - -static void -subst_stack_regs (insn, regstack) - rtx insn; - stack regstack; -{ - register rtx *note_link, note; - register int i; - - if (GET_CODE (insn) == CALL_INSN) - { - int top = regstack->top; - - /* If there are any floating point parameters to be passed in - registers for this call, make sure they are in the right - order. */ - - if (top >= 0) - { - straighten_stack (PREV_INSN (insn), regstack); - - /* Now mark the arguments as dead after the call. */ - - while (regstack->top >= 0) - { - CLEAR_HARD_REG_BIT (regstack->reg_set, FIRST_STACK_REG + regstack->top); - regstack->top--; - } - } - } - - /* Do the actual substitution if any stack regs are mentioned. - Since we only record whether entire insn mentions stack regs, and - subst_stack_regs_pat only works for patterns that contain stack regs, - we must check each pattern in a parallel here. A call_value_pop could - fail otherwise. */ - - if (stack_regs_mentioned (insn)) - { - int n_operands = asm_noperands (PATTERN (insn)); - if (n_operands >= 0) - { - /* This insn is an `asm' with operands. Decode the operands, - decide how many are inputs, and do register substitution. - Any REG_UNUSED notes will be handled by subst_asm_stack_regs. */ - - subst_asm_stack_regs (insn, regstack); - return; - } - - if (GET_CODE (PATTERN (insn)) == PARALLEL) - for (i = 0; i < XVECLEN (PATTERN (insn), 0); i++) - { - if (stack_regs_mentioned_p (XVECEXP (PATTERN (insn), 0, i))) - { - subst_stack_regs_pat (insn, regstack, - XVECEXP (PATTERN (insn), 0, i)); - - /* subst_stack_regs_pat may have deleted a no-op insn. */ - if (GET_CODE (insn) == NOTE) - break; - } - } - else - subst_stack_regs_pat (insn, regstack, PATTERN (insn)); - } - - /* subst_stack_regs_pat may have deleted a no-op insn. If so, any - REG_UNUSED will already have been dealt with, so just return. */ - - if (GET_CODE (insn) == NOTE) - return; - - /* If there is a REG_UNUSED note on a stack register on this insn, - the indicated reg must be popped. The REG_UNUSED note is removed, - since the form of the newly emitted pop insn references the reg, - making it no longer `unset'. */ - - note_link = ®_NOTES(insn); - for (note = *note_link; note; note = XEXP (note, 1)) - if (REG_NOTE_KIND (note) == REG_UNUSED && STACK_REG_P (XEXP (note, 0))) - { - *note_link = XEXP (note, 1); - insn = emit_pop_insn (insn, regstack, XEXP (note, 0), emit_insn_after); - } - else - note_link = &XEXP (note, 1); -} - -/* Change the organization of the stack so that it fits a new basic - block. Some registers might have to be popped, but there can never be - a register live in the new block that is not now live. - - Insert any needed insns before or after INSN. WHEN is emit_insn_before - or emit_insn_after. OLD is the original stack layout, and NEW is - the desired form. OLD is updated to reflect the code emitted, ie, it - will be the same as NEW upon return. - - This function will not preserve block_end[]. But that information - is no longer needed once this has executed. */ - -static void -change_stack (insn, old, new, when) - rtx insn; - stack old; - stack new; - rtx (*when)(); -{ - int reg; - - /* We will be inserting new insns "backwards", by calling emit_insn_before. - If we are to insert after INSN, find the next insn, and insert before - it. */ - - if (when == emit_insn_after) - insn = NEXT_INSN (insn); - - /* Pop any registers that are not needed in the new block. */ - - for (reg = old->top; reg >= 0; reg--) - if (! TEST_HARD_REG_BIT (new->reg_set, old->reg[reg])) - emit_pop_insn (insn, old, FP_MODE_REG (old->reg[reg], DFmode), - emit_insn_before); - - if (new->top == -2) - { - /* If the new block has never been processed, then it can inherit - the old stack order. */ - - new->top = old->top; - bcopy (old->reg, new->reg, sizeof (new->reg)); - } - else - { - /* This block has been entered before, and we must match the - previously selected stack order. */ - - /* By now, the only difference should be the order of the stack, - not their depth or liveliness. */ - - GO_IF_HARD_REG_EQUAL (old->reg_set, new->reg_set, win); - - abort (); - - win: - - if (old->top != new->top) - abort (); - - /* If the stack is not empty (new->top != -1), loop here emitting - swaps until the stack is correct. - - The worst case number of swaps emitted is N + 2, where N is the - depth of the stack. In some cases, the reg at the top of - stack may be correct, but swapped anyway in order to fix - other regs. But since we never swap any other reg away from - its correct slot, this algorithm will converge. */ - - if (new->top != -1) - do - { - /* Swap the reg at top of stack into the position it is - supposed to be in, until the correct top of stack appears. */ - - while (old->reg[old->top] != new->reg[new->top]) - { - for (reg = new->top; reg >= 0; reg--) - if (new->reg[reg] == old->reg[old->top]) - break; - - if (reg == -1) - abort (); - - emit_swap_insn (insn, old, - FP_MODE_REG (old->reg[reg], DFmode)); - } - - /* See if any regs remain incorrect. If so, bring an - incorrect reg to the top of stack, and let the while loop - above fix it. */ - - for (reg = new->top; reg >= 0; reg--) - if (new->reg[reg] != old->reg[reg]) - { - emit_swap_insn (insn, old, - FP_MODE_REG (old->reg[reg], DFmode)); - break; - } - } while (reg >= 0); - - /* At this point there must be no differences. */ - - for (reg = old->top; reg >= 0; reg--) - if (old->reg[reg] != new->reg[reg]) - abort (); - } -} - -/* Check PAT, which points to RTL in INSN, for a LABEL_REF. If it is - found, ensure that a jump from INSN to the code_label to which the - label_ref points ends up with the same stack as that at the - code_label. Do this by inserting insns just before the code_label to - pop and rotate the stack until it is in the correct order. REGSTACK - is the order of the register stack in INSN. - - Any code that is emitted here must not be later processed as part - of any block, as it will already contain hard register numbers. */ - -static void -goto_block_pat (insn, regstack, pat) - rtx insn; - stack regstack; - rtx pat; -{ - rtx label; - rtx new_jump, new_label, new_barrier; - rtx *ref; - stack label_stack; - struct stack_def temp_stack; - int reg; - - switch (GET_CODE (pat)) - { - case RETURN: - straighten_stack (PREV_INSN (insn), regstack); - return; - default: - { - int i, j; - char *fmt = GET_RTX_FORMAT (GET_CODE (pat)); - - for (i = GET_RTX_LENGTH (GET_CODE (pat)) - 1; i >= 0; i--) - { - if (fmt[i] == 'e') - goto_block_pat (insn, regstack, XEXP (pat, i)); - if (fmt[i] == 'E') - for (j = 0; j < XVECLEN (pat, i); j++) - goto_block_pat (insn, regstack, XVECEXP (pat, i, j)); - } - return; - } - case LABEL_REF:; - } - - label = XEXP (pat, 0); - if (GET_CODE (label) != CODE_LABEL) - abort (); - - /* First, see if in fact anything needs to be done to the stack at all. */ - if (INSN_UID (label) <= 0) - return; - - label_stack = &block_stack_in[BLOCK_NUM (label)]; - - if (label_stack->top == -2) - { - /* If the target block hasn't had a stack order selected, then - we need merely ensure that no pops are needed. */ - - for (reg = regstack->top; reg >= 0; reg--) - if (! TEST_HARD_REG_BIT (label_stack->reg_set, regstack->reg[reg])) - break; - - if (reg == -1) - { - /* change_stack will not emit any code in this case. */ - - change_stack (label, regstack, label_stack, emit_insn_after); - return; - } - } - else if (label_stack->top == regstack->top) - { - for (reg = label_stack->top; reg >= 0; reg--) - if (label_stack->reg[reg] != regstack->reg[reg]) - break; - - if (reg == -1) - return; - } - - /* At least one insn will need to be inserted before label. Insert - a jump around the code we are about to emit. Emit a label for the new - code, and point the original insn at this new label. We can't use - redirect_jump here, because we're using fld[4] of the code labels as - LABEL_REF chains, no NUSES counters. */ - - new_jump = emit_jump_insn_before (gen_jump (label), label); - record_label_references (new_jump, PATTERN (new_jump)); - JUMP_LABEL (new_jump) = label; - - new_barrier = emit_barrier_after (new_jump); - - new_label = gen_label_rtx (); - emit_label_after (new_label, new_barrier); - LABEL_REFS (new_label) = new_label; - - /* The old label_ref will no longer point to the code_label if now uses, - so strip the label_ref from the code_label's chain of references. */ - - for (ref = &LABEL_REFS (label); *ref != label; ref = &LABEL_NEXTREF (*ref)) - if (*ref == pat) - break; - - if (*ref == label) - abort (); - - *ref = LABEL_NEXTREF (*ref); - - XEXP (pat, 0) = new_label; - record_label_references (insn, PATTERN (insn)); - - if (JUMP_LABEL (insn) == label) - JUMP_LABEL (insn) = new_label; - - /* Now emit the needed code. */ - - temp_stack = *regstack; - - change_stack (new_label, &temp_stack, label_stack, emit_insn_after); -} - -/* Traverse all basic blocks in a function, converting the register - references in each insn from the "flat" register file that gcc uses, to - the stack-like registers the 387 uses. */ - -static void -convert_regs () -{ - register int block, reg; - register rtx insn, next; - struct stack_def regstack; - - for (block = 0; block < blocks; block++) - { - if (block_stack_in[block].top == -2) - { - /* This block has not been previously encountered. Choose a - default mapping for any stack regs live on entry */ - - block_stack_in[block].top = -1; - - for (reg = LAST_STACK_REG; reg >= FIRST_STACK_REG; reg--) - if (TEST_HARD_REG_BIT (block_stack_in[block].reg_set, reg)) - block_stack_in[block].reg[++block_stack_in[block].top] = reg; - } - - /* Process all insns in this block. Keep track of `next' here, - so that we don't process any insns emitted while making - substitutions in INSN. */ - - next = block_begin[block]; - regstack = block_stack_in[block]; - do - { - insn = next; - next = NEXT_INSN (insn); - - /* Don't bother processing unless there is a stack reg - mentioned or if it's a CALL_INSN (register passing of - floating point values). */ - - if (stack_regs_mentioned (insn) || GET_CODE (insn) == CALL_INSN) - subst_stack_regs (insn, ®stack); - - } while (insn != block_end[block]); - - /* For all further actions, INSN needs to be the last insn in - this basic block. If subst_stack_regs inserted additional - instructions after INSN, it is no longer the last one at - this point. */ - next = PREV_INSN (next); - - /* If subst_stack_regs inserted something after a JUMP_INSN, that - is almost certainly a bug. */ - if (GET_CODE (insn) == JUMP_INSN && insn != next) - abort (); - insn = next; - - /* Something failed if the stack life doesn't match. */ - - GO_IF_HARD_REG_EQUAL (regstack.reg_set, block_out_reg_set[block], win); - - abort (); - - win: - - /* Adjust the stack of this block on exit to match the stack of - the target block, or copy stack information into stack of - jump target if the target block's stack order hasn't been set - yet. */ - - if (GET_CODE (insn) == JUMP_INSN) - goto_block_pat (insn, ®stack, PATTERN (insn)); - - /* Likewise handle the case where we fall into the next block. */ - - if ((block < blocks - 1) && block_drops_in[block+1]) - change_stack (insn, ®stack, &block_stack_in[block+1], - emit_insn_after); - } - - /* If the last basic block is the end of a loop, and that loop has - regs live at its start, then the last basic block will have regs live - at its end that need to be popped before the function returns. */ - - { - int value_reg_low, value_reg_high; - value_reg_low = value_reg_high = -1; - { - rtx retvalue; - if ((retvalue = stack_result (current_function_decl))) - { - value_reg_low = REGNO (retvalue); - value_reg_high = value_reg_low + - HARD_REGNO_NREGS (value_reg_low, GET_MODE (retvalue)) - 1; - } - - } - for (reg = regstack.top; reg >= 0; reg--) - if (regstack.reg[reg] < value_reg_low - || regstack.reg[reg] > value_reg_high) - insn = emit_pop_insn (insn, ®stack, - FP_MODE_REG (regstack.reg[reg], DFmode), - emit_insn_after); - } - straighten_stack (insn, ®stack); -} - -/* Check expression PAT, which is in INSN, for label references. if - one is found, print the block number of destination to FILE. */ - -static void -print_blocks (file, insn, pat) - FILE *file; - rtx insn, pat; -{ - register RTX_CODE code = GET_CODE (pat); - register int i; - register char *fmt; - - if (code == LABEL_REF) - { - register rtx label = XEXP (pat, 0); - - if (GET_CODE (label) != CODE_LABEL) - abort (); - - fprintf (file, " %d", BLOCK_NUM (label)); - - return; - } - - fmt = GET_RTX_FORMAT (code); - for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) - { - if (fmt[i] == 'e') - print_blocks (file, insn, XEXP (pat, i)); - if (fmt[i] == 'E') - { - register int j; - for (j = 0; j < XVECLEN (pat, i); j++) - print_blocks (file, insn, XVECEXP (pat, i, j)); - } - } -} - -/* Write information about stack registers and stack blocks into FILE. - This is part of making a debugging dump. */ - -static void -dump_stack_info (file) - FILE *file; -{ - register int block; - - fprintf (file, "\n%d stack blocks.\n", blocks); - for (block = 0; block < blocks; block++) - { - register rtx head, jump, end; - register int regno; - - fprintf (file, "\nStack block %d: first insn %d, last %d.\n", - block, INSN_UID (block_begin[block]), - INSN_UID (block_end[block])); - - head = block_begin[block]; - - fprintf (file, "Reached from blocks: "); - if (GET_CODE (head) == CODE_LABEL) - for (jump = LABEL_REFS (head); - jump != head; - jump = LABEL_NEXTREF (jump)) - { - register int from_block = BLOCK_NUM (CONTAINING_INSN (jump)); - fprintf (file, " %d", from_block); - } - if (block_drops_in[block]) - fprintf (file, " previous"); - - fprintf (file, "\nlive stack registers on block entry: "); - for (regno = FIRST_STACK_REG; regno <= LAST_STACK_REG; regno++) - { - if (TEST_HARD_REG_BIT (block_stack_in[block].reg_set, regno)) - fprintf (file, "%d ", regno); - } - - fprintf (file, "\nlive stack registers on block exit: "); - for (regno = FIRST_STACK_REG; regno <= LAST_STACK_REG; regno++) - { - if (TEST_HARD_REG_BIT (block_out_reg_set[block], regno)) - fprintf (file, "%d ", regno); - } - - end = block_end[block]; - - fprintf (file, "\nJumps to blocks: "); - if (GET_CODE (end) == JUMP_INSN) - print_blocks (file, end, PATTERN (end)); - - if (block + 1 < blocks && block_drops_in[block+1]) - fprintf (file, " next"); - else if (block + 1 == blocks - || (GET_CODE (end) == JUMP_INSN - && GET_CODE (PATTERN (end)) == RETURN)) - fprintf (file, " return"); - - fprintf (file, "\n"); - } -} -#endif /* STACK_REGS */ |