mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-11-19 01:13:25 +00:00
f141cc46fa
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29351 91177308-0d34-0410-b5e6-96231b3b80d8
206 lines
7.0 KiB
C++
206 lines
7.0 KiB
C++
//===-- X86JITInfo.cpp - Implement the JIT interfaces for the X86 target --===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file was developed by the LLVM research group and 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 "llvm/CodeGen/MachineCodeEmitter.h"
|
|
#include "llvm/Config/alloca.h"
|
|
#include <cstdlib>
|
|
#include <iostream>
|
|
using namespace llvm;
|
|
|
|
#ifdef _MSC_VER
|
|
extern "C" void *_AddressOfReturnAddress(void);
|
|
#pragma intrinsic(_AddressOfReturnAddress)
|
|
#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.
|
|
}
|
|
|
|
|
|
/// JITCompilerFunction - This contains the address of the JIT function used to
|
|
/// compile a function lazily.
|
|
static TargetJITInfo::JITCompilerFn JITCompilerFunction;
|
|
|
|
// Provide a wrapper for X86CompilationCallback2 that saves non-traditional
|
|
// callee saved registers, for the fastcc calling convention.
|
|
extern "C" {
|
|
#if defined(__i386__) || defined(i386) || defined(_M_IX86)
|
|
#ifndef _MSC_VER
|
|
void X86CompilationCallback(void);
|
|
asm(
|
|
".text\n"
|
|
".align 8\n"
|
|
#if defined(__CYGWIN__) || defined(__APPLE__) || defined(__MINGW32__)
|
|
".globl _X86CompilationCallback\n"
|
|
"_X86CompilationCallback:\n"
|
|
#else
|
|
".globl X86CompilationCallback\n"
|
|
"X86CompilationCallback:\n"
|
|
#endif
|
|
"pushl %ebp\n"
|
|
"movl %esp, %ebp\n" // Standard prologue
|
|
#if FASTCC_NUM_INT_ARGS_INREGS > 0
|
|
"pushl %eax\n"
|
|
"pushl %edx\n" // Save EAX/EDX
|
|
#endif
|
|
#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"
|
|
#if defined(__CYGWIN__) || defined(__MINGW32__) || defined(__APPLE__)
|
|
"call _X86CompilationCallback2\n"
|
|
#else
|
|
"call X86CompilationCallback2\n"
|
|
#endif
|
|
"movl %ebp, %esp\n" // Restore ESP
|
|
#if FASTCC_NUM_INT_ARGS_INREGS > 0
|
|
"subl $8, %esp\n"
|
|
"popl %edx\n"
|
|
"popl %eax\n"
|
|
#endif
|
|
"popl %ebp\n"
|
|
"ret\n");
|
|
#else
|
|
void X86CompilationCallback2(void);
|
|
|
|
_declspec(naked) void X86CompilationCallback(void) {
|
|
__asm {
|
|
push eax
|
|
push edx
|
|
call X86CompilationCallback2
|
|
pop edx
|
|
pop eax
|
|
ret
|
|
}
|
|
}
|
|
#endif // _MSC_VER
|
|
|
|
#else // Not an i386 host
|
|
void X86CompilationCallback() {
|
|
std::cerr << "Cannot call X86CompilationCallback() on a non-x86 arch!\n";
|
|
abort();
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/// X86CompilationCallback - 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.
|
|
#ifdef _MSC_VER
|
|
extern "C" void X86CompilationCallback2() {
|
|
assert(sizeof(size_t) == 4); // FIXME: handle Win64
|
|
unsigned *RetAddrLoc = (unsigned *)_AddressOfReturnAddress();
|
|
RetAddrLoc += 3; // skip over ret addr, edx, eax
|
|
unsigned RetAddr = *RetAddrLoc;
|
|
#else
|
|
extern "C" void X86CompilationCallback2(intptr_t *StackPtr, intptr_t RetAddr) {
|
|
intptr_t *RetAddrLoc = &StackPtr[1];
|
|
#endif
|
|
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*)(intptr_t)RetAddr)[0] == 0xCD;
|
|
|
|
// The call instruction should have pushed the return value onto the stack...
|
|
RetAddr -= 4; // Backtrack to the reference itself...
|
|
|
|
#if 0
|
|
DEBUG(std::cerr << "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.
|
|
assert(((unsigned char*)(intptr_t)RetAddr)[-1] == 0xE8 &&"Not a call instr!");
|
|
|
|
unsigned NewVal = (intptr_t)JITCompilerFunction((void*)(intptr_t)RetAddr);
|
|
|
|
// Rewrite the call target... so that we don't end up here every time we
|
|
// execute the call.
|
|
*(unsigned*)(intptr_t)RetAddr = NewVal-RetAddr-4;
|
|
|
|
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
|
|
// 0xCD byte (interrupt) dead, so the marker doesn't effect anything.
|
|
((unsigned char*)(intptr_t)RetAddr)[-1] = 0xE9;
|
|
}
|
|
|
|
// Change the return address to reexecute the call instruction...
|
|
*RetAddrLoc -= 5;
|
|
}
|
|
|
|
TargetJITInfo::LazyResolverFn
|
|
X86JITInfo::getLazyResolverFunction(JITCompilerFn F) {
|
|
JITCompilerFunction = F;
|
|
return X86CompilationCallback;
|
|
}
|
|
|
|
void *X86JITInfo::emitFunctionStub(void *Fn, MachineCodeEmitter &MCE) {
|
|
// Note, we cast to intptr_t here to silence a -pedantic warning that
|
|
// complains about casting a function pointer to a normal pointer.
|
|
if (Fn != (void*)(intptr_t)X86CompilationCallback) {
|
|
MCE.startFunctionStub(5);
|
|
MCE.emitByte(0xE9);
|
|
MCE.emitWordLE((intptr_t)Fn-MCE.getCurrentPCValue()-4);
|
|
return MCE.finishFunctionStub(0);
|
|
}
|
|
|
|
MCE.startFunctionStub(6);
|
|
MCE.emitByte(0xE8); // Call with 32 bit pc-rel destination...
|
|
|
|
MCE.emitWordLE((intptr_t)Fn-MCE.getCurrentPCValue()-4);
|
|
|
|
MCE.emitByte(0xCD); // Interrupt - Just a marker identifying the stub!
|
|
return MCE.finishFunctionStub(0);
|
|
}
|
|
|
|
/// 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;
|
|
*((intptr_t*)RelocPos) += ResultPtr;
|
|
break;
|
|
case X86::reloc_absolute_word:
|
|
// Absolute relocation, just add the relocated value to the value already
|
|
// in memory.
|
|
*((intptr_t*)RelocPos) += ResultPtr;
|
|
break;
|
|
}
|
|
}
|
|
}
|