diff options
Diffstat (limited to 'contrib/llvm/lib/Target/X86/X86JITInfo.cpp')
| -rw-r--r-- | contrib/llvm/lib/Target/X86/X86JITInfo.cpp | 566 |
1 files changed, 566 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/X86/X86JITInfo.cpp b/contrib/llvm/lib/Target/X86/X86JITInfo.cpp new file mode 100644 index 000000000000..6f0a8d91cb58 --- /dev/null +++ b/contrib/llvm/lib/Target/X86/X86JITInfo.cpp @@ -0,0 +1,566 @@ +//===-- X86JITInfo.cpp - Implement the JIT interfaces for the X86 target --===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements the JIT interfaces for the X86 target. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "jit" +#include "X86JITInfo.h" +#include "X86Relocations.h" +#include "X86Subtarget.h" +#include "X86TargetMachine.h" +#include "llvm/Function.h" +#include "llvm/Support/Compiler.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/System/Valgrind.h" +#include <cstdlib> +#include <cstring> +using namespace llvm; + +// Determine the platform we're running on +#if defined (__x86_64__) || defined (_M_AMD64) || defined (_M_X64) +# define X86_64_JIT +#elif defined(__i386__) || defined(i386) || defined(_M_IX86) +# define X86_32_JIT +#endif + +void X86JITInfo::replaceMachineCodeForFunction(void *Old, void *New) { + unsigned char *OldByte = (unsigned char *)Old; + *OldByte++ = 0xE9; // Emit JMP opcode. + unsigned *OldWord = (unsigned *)OldByte; + unsigned NewAddr = (intptr_t)New; + unsigned OldAddr = (intptr_t)OldWord; + *OldWord = NewAddr - OldAddr - 4; // Emit PC-relative addr of New code. + + // X86 doesn't need to invalidate the processor cache, so just invalidate + // Valgrind's cache directly. + sys::ValgrindDiscardTranslations(Old, 5); +} + + +/// JITCompilerFunction - This contains the address of the JIT function used to +/// compile a function lazily. +static TargetJITInfo::JITCompilerFn JITCompilerFunction; + +// Get the ASMPREFIX for the current host. This is often '_'. +#ifndef __USER_LABEL_PREFIX__ +#define __USER_LABEL_PREFIX__ +#endif +#define GETASMPREFIX2(X) #X +#define GETASMPREFIX(X) GETASMPREFIX2(X) +#define ASMPREFIX GETASMPREFIX(__USER_LABEL_PREFIX__) + +// For ELF targets, use a .size and .type directive, to let tools +// know the extent of functions defined in assembler. +#if defined(__ELF__) +# define SIZE(sym) ".size " #sym ", . - " #sym "\n" +# define TYPE_FUNCTION(sym) ".type " #sym ", @function\n" +#else +# define SIZE(sym) +# define TYPE_FUNCTION(sym) +#endif + +// Provide a convenient way for disabling usage of CFI directives. +// This is needed for old/broken assemblers (for example, gas on +// Darwin is pretty old and doesn't support these directives) +#if defined(__APPLE__) +# define CFI(x) +#else +// FIXME: Disable this until we really want to use it. Also, we will +// need to add some workarounds for compilers, which support +// only subset of these directives. +# define CFI(x) +#endif + +// Provide a wrapper for X86CompilationCallback2 that saves non-traditional +// callee saved registers, for the fastcc calling convention. +extern "C" { +#if defined(X86_64_JIT) +# ifndef _MSC_VER + // No need to save EAX/EDX for X86-64. + void X86CompilationCallback(void); + asm( + ".text\n" + ".align 8\n" + ".globl " ASMPREFIX "X86CompilationCallback\n" + TYPE_FUNCTION(X86CompilationCallback) + ASMPREFIX "X86CompilationCallback:\n" + CFI(".cfi_startproc\n") + // Save RBP + "pushq %rbp\n" + CFI(".cfi_def_cfa_offset 16\n") + CFI(".cfi_offset %rbp, -16\n") + // Save RSP + "movq %rsp, %rbp\n" + CFI(".cfi_def_cfa_register %rbp\n") + // Save all int arg registers + "pushq %rdi\n" + CFI(".cfi_rel_offset %rdi, 0\n") + "pushq %rsi\n" + CFI(".cfi_rel_offset %rsi, 8\n") + "pushq %rdx\n" + CFI(".cfi_rel_offset %rdx, 16\n") + "pushq %rcx\n" + CFI(".cfi_rel_offset %rcx, 24\n") + "pushq %r8\n" + CFI(".cfi_rel_offset %r8, 32\n") + "pushq %r9\n" + CFI(".cfi_rel_offset %r9, 40\n") + // Align stack on 16-byte boundary. ESP might not be properly aligned + // (8 byte) if this is called from an indirect stub. + "andq $-16, %rsp\n" + // Save all XMM arg registers + "subq $128, %rsp\n" + "movaps %xmm0, (%rsp)\n" + "movaps %xmm1, 16(%rsp)\n" + "movaps %xmm2, 32(%rsp)\n" + "movaps %xmm3, 48(%rsp)\n" + "movaps %xmm4, 64(%rsp)\n" + "movaps %xmm5, 80(%rsp)\n" + "movaps %xmm6, 96(%rsp)\n" + "movaps %xmm7, 112(%rsp)\n" + // JIT callee + "movq %rbp, %rdi\n" // Pass prev frame and return address + "movq 8(%rbp), %rsi\n" + "call " ASMPREFIX "X86CompilationCallback2\n" + // Restore all XMM arg registers + "movaps 112(%rsp), %xmm7\n" + "movaps 96(%rsp), %xmm6\n" + "movaps 80(%rsp), %xmm5\n" + "movaps 64(%rsp), %xmm4\n" + "movaps 48(%rsp), %xmm3\n" + "movaps 32(%rsp), %xmm2\n" + "movaps 16(%rsp), %xmm1\n" + "movaps (%rsp), %xmm0\n" + // Restore RSP + "movq %rbp, %rsp\n" + CFI(".cfi_def_cfa_register %rsp\n") + // Restore all int arg registers + "subq $48, %rsp\n" + CFI(".cfi_adjust_cfa_offset 48\n") + "popq %r9\n" + CFI(".cfi_adjust_cfa_offset -8\n") + CFI(".cfi_restore %r9\n") + "popq %r8\n" + CFI(".cfi_adjust_cfa_offset -8\n") + CFI(".cfi_restore %r8\n") + "popq %rcx\n" + CFI(".cfi_adjust_cfa_offset -8\n") + CFI(".cfi_restore %rcx\n") + "popq %rdx\n" + CFI(".cfi_adjust_cfa_offset -8\n") + CFI(".cfi_restore %rdx\n") + "popq %rsi\n" + CFI(".cfi_adjust_cfa_offset -8\n") + CFI(".cfi_restore %rsi\n") + "popq %rdi\n" + CFI(".cfi_adjust_cfa_offset -8\n") + CFI(".cfi_restore %rdi\n") + // Restore RBP + "popq %rbp\n" + CFI(".cfi_adjust_cfa_offset -8\n") + CFI(".cfi_restore %rbp\n") + "ret\n" + CFI(".cfi_endproc\n") + SIZE(X86CompilationCallback) + ); +# else + // No inline assembler support on this platform. The routine is in external + // file. + void X86CompilationCallback(); + +# endif +#elif defined (X86_32_JIT) +# ifndef _MSC_VER + void X86CompilationCallback(void); + asm( + ".text\n" + ".align 8\n" + ".globl " ASMPREFIX "X86CompilationCallback\n" + TYPE_FUNCTION(X86CompilationCallback) + ASMPREFIX "X86CompilationCallback:\n" + CFI(".cfi_startproc\n") + "pushl %ebp\n" + CFI(".cfi_def_cfa_offset 8\n") + CFI(".cfi_offset %ebp, -8\n") + "movl %esp, %ebp\n" // Standard prologue + CFI(".cfi_def_cfa_register %ebp\n") + "pushl %eax\n" + CFI(".cfi_rel_offset %eax, 0\n") + "pushl %edx\n" // Save EAX/EDX/ECX + CFI(".cfi_rel_offset %edx, 4\n") + "pushl %ecx\n" + CFI(".cfi_rel_offset %ecx, 8\n") +# if defined(__APPLE__) + "andl $-16, %esp\n" // Align ESP on 16-byte boundary +# endif + "subl $16, %esp\n" + "movl 4(%ebp), %eax\n" // Pass prev frame and return address + "movl %eax, 4(%esp)\n" + "movl %ebp, (%esp)\n" + "call " ASMPREFIX "X86CompilationCallback2\n" + "movl %ebp, %esp\n" // Restore ESP + CFI(".cfi_def_cfa_register %esp\n") + "subl $12, %esp\n" + CFI(".cfi_adjust_cfa_offset 12\n") + "popl %ecx\n" + CFI(".cfi_adjust_cfa_offset -4\n") + CFI(".cfi_restore %ecx\n") + "popl %edx\n" + CFI(".cfi_adjust_cfa_offset -4\n") + CFI(".cfi_restore %edx\n") + "popl %eax\n" + CFI(".cfi_adjust_cfa_offset -4\n") + CFI(".cfi_restore %eax\n") + "popl %ebp\n" + CFI(".cfi_adjust_cfa_offset -4\n") + CFI(".cfi_restore %ebp\n") + "ret\n" + CFI(".cfi_endproc\n") + SIZE(X86CompilationCallback) + ); + + // Same as X86CompilationCallback but also saves XMM argument registers. + void X86CompilationCallback_SSE(void); + asm( + ".text\n" + ".align 8\n" + ".globl " ASMPREFIX "X86CompilationCallback_SSE\n" + TYPE_FUNCTION(X86CompilationCallback_SSE) + ASMPREFIX "X86CompilationCallback_SSE:\n" + CFI(".cfi_startproc\n") + "pushl %ebp\n" + CFI(".cfi_def_cfa_offset 8\n") + CFI(".cfi_offset %ebp, -8\n") + "movl %esp, %ebp\n" // Standard prologue + CFI(".cfi_def_cfa_register %ebp\n") + "pushl %eax\n" + CFI(".cfi_rel_offset %eax, 0\n") + "pushl %edx\n" // Save EAX/EDX/ECX + CFI(".cfi_rel_offset %edx, 4\n") + "pushl %ecx\n" + CFI(".cfi_rel_offset %ecx, 8\n") + "andl $-16, %esp\n" // Align ESP on 16-byte boundary + // Save all XMM arg registers + "subl $64, %esp\n" + // FIXME: provide frame move information for xmm registers. + // This can be tricky, because CFA register is ebp (unaligned) + // and we need to produce offsets relative to it. + "movaps %xmm0, (%esp)\n" + "movaps %xmm1, 16(%esp)\n" + "movaps %xmm2, 32(%esp)\n" + "movaps %xmm3, 48(%esp)\n" + "subl $16, %esp\n" + "movl 4(%ebp), %eax\n" // Pass prev frame and return address + "movl %eax, 4(%esp)\n" + "movl %ebp, (%esp)\n" + "call " ASMPREFIX "X86CompilationCallback2\n" + "addl $16, %esp\n" + "movaps 48(%esp), %xmm3\n" + CFI(".cfi_restore %xmm3\n") + "movaps 32(%esp), %xmm2\n" + CFI(".cfi_restore %xmm2\n") + "movaps 16(%esp), %xmm1\n" + CFI(".cfi_restore %xmm1\n") + "movaps (%esp), %xmm0\n" + CFI(".cfi_restore %xmm0\n") + "movl %ebp, %esp\n" // Restore ESP + CFI(".cfi_def_cfa_register esp\n") + "subl $12, %esp\n" + CFI(".cfi_adjust_cfa_offset 12\n") + "popl %ecx\n" + CFI(".cfi_adjust_cfa_offset -4\n") + CFI(".cfi_restore %ecx\n") + "popl %edx\n" + CFI(".cfi_adjust_cfa_offset -4\n") + CFI(".cfi_restore %edx\n") + "popl %eax\n" + CFI(".cfi_adjust_cfa_offset -4\n") + CFI(".cfi_restore %eax\n") + "popl %ebp\n" + CFI(".cfi_adjust_cfa_offset -4\n") + CFI(".cfi_restore %ebp\n") + "ret\n" + CFI(".cfi_endproc\n") + SIZE(X86CompilationCallback_SSE) + ); +# else + void X86CompilationCallback2(intptr_t *StackPtr, intptr_t RetAddr); + + _declspec(naked) void X86CompilationCallback(void) { + __asm { + push ebp + mov ebp, esp + push eax + push edx + push ecx + and esp, -16 + sub esp, 16 + mov eax, dword ptr [ebp+4] + mov dword ptr [esp+4], eax + mov dword ptr [esp], ebp + call X86CompilationCallback2 + mov esp, ebp + sub esp, 12 + pop ecx + pop edx + pop eax + pop ebp + ret + } + } + +# endif // _MSC_VER + +#else // Not an i386 host + void X86CompilationCallback() { + llvm_unreachable("Cannot call X86CompilationCallback() on a non-x86 arch!"); + } +#endif +} + +/// X86CompilationCallback2 - This is the target-specific function invoked by the +/// function stub when we did not know the real target of a call. This function +/// must locate the start of the stub or call site and pass it into the JIT +/// compiler function. +extern "C" { +#if !(defined (X86_64_JIT) && defined(_MSC_VER)) + // the following function is called only from this translation unit, + // unless we are under 64bit Windows with MSC, where there is + // no support for inline assembly +static +#endif +void ATTRIBUTE_USED +X86CompilationCallback2(intptr_t *StackPtr, intptr_t RetAddr) { + intptr_t *RetAddrLoc = &StackPtr[1]; + assert(*RetAddrLoc == RetAddr && + "Could not find return address on the stack!"); + + // It's a stub if there is an interrupt marker after the call. + bool isStub = ((unsigned char*)RetAddr)[0] == 0xCE; + + // The call instruction should have pushed the return value onto the stack... +#if defined (X86_64_JIT) + RetAddr--; // Backtrack to the reference itself... +#else + RetAddr -= 4; // Backtrack to the reference itself... +#endif + +#if 0 + DEBUG(dbgs() << "In callback! Addr=" << (void*)RetAddr + << " ESP=" << (void*)StackPtr + << ": Resolving call to function: " + << TheVM->getFunctionReferencedName((void*)RetAddr) << "\n"); +#endif + + // Sanity check to make sure this really is a call instruction. +#if defined (X86_64_JIT) + assert(((unsigned char*)RetAddr)[-2] == 0x41 &&"Not a call instr!"); + assert(((unsigned char*)RetAddr)[-1] == 0xFF &&"Not a call instr!"); +#else + assert(((unsigned char*)RetAddr)[-1] == 0xE8 &&"Not a call instr!"); +#endif + + intptr_t NewVal = (intptr_t)JITCompilerFunction((void*)RetAddr); + + // Rewrite the call target... so that we don't end up here every time we + // execute the call. +#if defined (X86_64_JIT) + assert(isStub && + "X86-64 doesn't support rewriting non-stub lazy compilation calls:" + " the call instruction varies too much."); +#else + *(intptr_t *)RetAddr = (intptr_t)(NewVal-RetAddr-4); +#endif + + if (isStub) { + // If this is a stub, rewrite the call into an unconditional branch + // instruction so that two return addresses are not pushed onto the stack + // when the requested function finally gets called. This also makes the + // 0xCE byte (interrupt) dead, so the marker doesn't effect anything. +#if defined (X86_64_JIT) + // If the target address is within 32-bit range of the stub, use a + // PC-relative branch instead of loading the actual address. (This is + // considerably shorter than the 64-bit immediate load already there.) + // We assume here intptr_t is 64 bits. + intptr_t diff = NewVal-RetAddr+7; + if (diff >= -2147483648LL && diff <= 2147483647LL) { + *(unsigned char*)(RetAddr-0xc) = 0xE9; + *(intptr_t *)(RetAddr-0xb) = diff & 0xffffffff; + } else { + *(intptr_t *)(RetAddr - 0xa) = NewVal; + ((unsigned char*)RetAddr)[0] = (2 | (4 << 3) | (3 << 6)); + } + sys::ValgrindDiscardTranslations((void*)(RetAddr-0xc), 0xd); +#else + ((unsigned char*)RetAddr)[-1] = 0xE9; + sys::ValgrindDiscardTranslations((void*)(RetAddr-1), 5); +#endif + } + + // Change the return address to reexecute the call instruction... +#if defined (X86_64_JIT) + *RetAddrLoc -= 0xd; +#else + *RetAddrLoc -= 5; +#endif +} +} + +TargetJITInfo::LazyResolverFn +X86JITInfo::getLazyResolverFunction(JITCompilerFn F) { + JITCompilerFunction = F; + +#if defined (X86_32_JIT) && !defined (_MSC_VER) + if (Subtarget->hasSSE1()) + return X86CompilationCallback_SSE; +#endif + + return X86CompilationCallback; +} + +X86JITInfo::X86JITInfo(X86TargetMachine &tm) : TM(tm) { + Subtarget = &TM.getSubtarget<X86Subtarget>(); + useGOT = 0; + TLSOffset = 0; +} + +void *X86JITInfo::emitGlobalValueIndirectSym(const GlobalValue* GV, void *ptr, + JITCodeEmitter &JCE) { +#if defined (X86_64_JIT) + const unsigned Alignment = 8; + uint8_t Buffer[8]; + uint8_t *Cur = Buffer; + MachineCodeEmitter::emitWordLEInto(Cur, (unsigned)(intptr_t)ptr); + MachineCodeEmitter::emitWordLEInto(Cur, (unsigned)(((intptr_t)ptr) >> 32)); +#else + const unsigned Alignment = 4; + uint8_t Buffer[4]; + uint8_t *Cur = Buffer; + MachineCodeEmitter::emitWordLEInto(Cur, (intptr_t)ptr); +#endif + return JCE.allocIndirectGV(GV, Buffer, sizeof(Buffer), Alignment); +} + +TargetJITInfo::StubLayout X86JITInfo::getStubLayout() { + // The 64-bit stub contains: + // movabs r10 <- 8-byte-target-address # 10 bytes + // call|jmp *r10 # 3 bytes + // The 32-bit stub contains a 5-byte call|jmp. + // If the stub is a call to the compilation callback, an extra byte is added + // to mark it as a stub. + StubLayout Result = {14, 4}; + return Result; +} + +void *X86JITInfo::emitFunctionStub(const Function* F, void *Target, + JITCodeEmitter &JCE) { + // Note, we cast to intptr_t here to silence a -pedantic warning that + // complains about casting a function pointer to a normal pointer. +#if defined (X86_32_JIT) && !defined (_MSC_VER) + bool NotCC = (Target != (void*)(intptr_t)X86CompilationCallback && + Target != (void*)(intptr_t)X86CompilationCallback_SSE); +#else + bool NotCC = Target != (void*)(intptr_t)X86CompilationCallback; +#endif + JCE.emitAlignment(4); + void *Result = (void*)JCE.getCurrentPCValue(); + if (NotCC) { +#if defined (X86_64_JIT) + JCE.emitByte(0x49); // REX prefix + JCE.emitByte(0xB8+2); // movabsq r10 + JCE.emitWordLE((unsigned)(intptr_t)Target); + JCE.emitWordLE((unsigned)(((intptr_t)Target) >> 32)); + JCE.emitByte(0x41); // REX prefix + JCE.emitByte(0xFF); // jmpq *r10 + JCE.emitByte(2 | (4 << 3) | (3 << 6)); +#else + JCE.emitByte(0xE9); + JCE.emitWordLE((intptr_t)Target-JCE.getCurrentPCValue()-4); +#endif + return Result; + } + +#if defined (X86_64_JIT) + JCE.emitByte(0x49); // REX prefix + JCE.emitByte(0xB8+2); // movabsq r10 + JCE.emitWordLE((unsigned)(intptr_t)Target); + JCE.emitWordLE((unsigned)(((intptr_t)Target) >> 32)); + JCE.emitByte(0x41); // REX prefix + JCE.emitByte(0xFF); // callq *r10 + JCE.emitByte(2 | (2 << 3) | (3 << 6)); +#else + JCE.emitByte(0xE8); // Call with 32 bit pc-rel destination... + + JCE.emitWordLE((intptr_t)Target-JCE.getCurrentPCValue()-4); +#endif + + // This used to use 0xCD, but that value is used by JITMemoryManager to + // initialize the buffer with garbage, which means it may follow a + // noreturn function call, confusing X86CompilationCallback2. PR 4929. + JCE.emitByte(0xCE); // Interrupt - Just a marker identifying the stub! + return Result; +} + +/// getPICJumpTableEntry - Returns the value of the jumptable entry for the +/// specific basic block. +uintptr_t X86JITInfo::getPICJumpTableEntry(uintptr_t BB, uintptr_t Entry) { +#if defined(X86_64_JIT) + return BB - Entry; +#else + return BB - PICBase; +#endif +} + +/// relocate - Before the JIT can run a block of code that has been emitted, +/// it must rewrite the code to contain the actual addresses of any +/// referenced global symbols. +void X86JITInfo::relocate(void *Function, MachineRelocation *MR, + unsigned NumRelocs, unsigned char* GOTBase) { + for (unsigned i = 0; i != NumRelocs; ++i, ++MR) { + void *RelocPos = (char*)Function + MR->getMachineCodeOffset(); + intptr_t ResultPtr = (intptr_t)MR->getResultPointer(); + switch ((X86::RelocationType)MR->getRelocationType()) { + case X86::reloc_pcrel_word: { + // PC relative relocation, add the relocated value to the value already in + // memory, after we adjust it for where the PC is. + ResultPtr = ResultPtr -(intptr_t)RelocPos - 4 - MR->getConstantVal(); + *((unsigned*)RelocPos) += (unsigned)ResultPtr; + break; + } + case X86::reloc_picrel_word: { + // PIC base relative relocation, add the relocated value to the value + // already in memory, after we adjust it for where the PIC base is. + ResultPtr = ResultPtr - ((intptr_t)Function + MR->getConstantVal()); + *((unsigned*)RelocPos) += (unsigned)ResultPtr; + break; + } + case X86::reloc_absolute_word: + case X86::reloc_absolute_word_sext: + // Absolute relocation, just add the relocated value to the value already + // in memory. + *((unsigned*)RelocPos) += (unsigned)ResultPtr; + break; + case X86::reloc_absolute_dword: + *((intptr_t*)RelocPos) += ResultPtr; + break; + } + } +} + +char* X86JITInfo::allocateThreadLocalMemory(size_t size) { +#if defined(X86_32_JIT) && !defined(__APPLE__) && !defined(_MSC_VER) + TLSOffset -= size; + return TLSOffset; +#else + llvm_unreachable("Cannot allocate thread local storage on this arch!"); + return 0; +#endif +} |