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Diffstat (limited to 'contrib/llvm/lib/Target/Mips/MipsJITInfo.cpp')
| -rw-r--r-- | contrib/llvm/lib/Target/Mips/MipsJITInfo.cpp | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/Mips/MipsJITInfo.cpp b/contrib/llvm/lib/Target/Mips/MipsJITInfo.cpp new file mode 100644 index 0000000..28c2b48 --- /dev/null +++ b/contrib/llvm/lib/Target/Mips/MipsJITInfo.cpp @@ -0,0 +1,230 @@ +//===- MipsJITInfo.cpp - Implement the JIT interfaces for the Mips 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 Mips target. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "jit" +#include "MipsJITInfo.h" +#include "MipsInstrInfo.h" +#include "MipsRelocations.h" +#include "MipsSubtarget.h" +#include "llvm/Function.h" +#include "llvm/CodeGen/JITCodeEmitter.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/raw_ostream.h" +#include "llvm/Support/Memory.h" +#include <cstdlib> +using namespace llvm; + + +void MipsJITInfo::replaceMachineCodeForFunction(void *Old, void *New) { + report_fatal_error("MipsJITInfo::replaceMachineCodeForFunction"); +} + +/// 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__) + +// CompilationCallback stub - We can't use a C function with inline assembly in +// it, because the prolog/epilog inserted by GCC won't work for us. Instead, +// write our own wrapper, which does things our way, so we have complete control +// over register saving and restoring. This code saves registers, calls +// MipsCompilationCallbackC and restores registers. +extern "C" { +#if defined (__mips__) +void MipsCompilationCallback(); + + asm( + ".text\n" + ".align 2\n" + ".globl " ASMPREFIX "MipsCompilationCallback\n" + ASMPREFIX "MipsCompilationCallback:\n" + ".ent " ASMPREFIX "MipsCompilationCallback\n" + ".frame $29, 32, $31\n" + ".set noreorder\n" + ".cpload $t9\n" + + "addiu $sp, $sp, -60\n" + ".cprestore 16\n" + + // Save argument registers a0, a1, a2, a3, f12, f14 since they may contain + // stuff for the real target function right now. We have to act as if this + // whole compilation callback doesn't exist as far as the caller is + // concerned. We also need to save the ra register since it contains the + // original return address, and t8 register since it contains the address + // of the end of function stub. + "sw $a0, 20($sp)\n" + "sw $a1, 24($sp)\n" + "sw $a2, 28($sp)\n" + "sw $a3, 32($sp)\n" + "sw $ra, 36($sp)\n" + "sw $t8, 40($sp)\n" + "sdc1 $f12, 44($sp)\n" + "sdc1 $f14, 52($sp)\n" + + // t8 points at the end of function stub. Pass the beginning of the stub + // to the MipsCompilationCallbackC. + "addiu $a0, $t8, -16\n" + "jal " ASMPREFIX "MipsCompilationCallbackC\n" + "nop\n" + + // Restore registers. + "lw $a0, 20($sp)\n" + "lw $a1, 24($sp)\n" + "lw $a2, 28($sp)\n" + "lw $a3, 32($sp)\n" + "lw $ra, 36($sp)\n" + "lw $t8, 40($sp)\n" + "ldc1 $f12, 44($sp)\n" + "ldc1 $f14, 52($sp)\n" + "addiu $sp, $sp, 60\n" + + // Jump to the (newly modified) stub to invoke the real function. + "addiu $t8, $t8, -16\n" + "jr $t8\n" + "nop\n" + + ".set reorder\n" + ".end " ASMPREFIX "MipsCompilationCallback\n" + ); +#else // host != Mips + void MipsCompilationCallback() { + llvm_unreachable( + "Cannot call MipsCompilationCallback() on a non-Mips arch!"); + } +#endif +} + +/// MipsCompilationCallbackC - 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" void MipsCompilationCallbackC(intptr_t StubAddr) { + // Get the address of the compiled code for this function. + intptr_t NewVal = (intptr_t) JITCompilerFunction((void*) StubAddr); + + // Rewrite the function stub so that we don't end up here every time we + // execute the call. We're replacing the first four instructions of the + // stub with code that jumps to the compiled function: + // lui $t9, %hi(NewVal) + // addiu $t9, $t9, %lo(NewVal) + // jr $t9 + // nop + + int Hi = ((unsigned)NewVal & 0xffff0000) >> 16; + if ((NewVal & 0x8000) != 0) + Hi++; + int Lo = (int)(NewVal & 0xffff); + + *(intptr_t *)(StubAddr) = 0xf << 26 | 25 << 16 | Hi; + *(intptr_t *)(StubAddr + 4) = 9 << 26 | 25 << 21 | 25 << 16 | Lo; + *(intptr_t *)(StubAddr + 8) = 25 << 21 | 8; + *(intptr_t *)(StubAddr + 12) = 0; + + sys::Memory::InvalidateInstructionCache((void*) StubAddr, 16); +} + +TargetJITInfo::LazyResolverFn MipsJITInfo::getLazyResolverFunction( + JITCompilerFn F) { + JITCompilerFunction = F; + return MipsCompilationCallback; +} + +TargetJITInfo::StubLayout MipsJITInfo::getStubLayout() { + // The stub contains 4 4-byte instructions, aligned at 4 bytes. See + // emitFunctionStub for details. + StubLayout Result = { 4*4, 4 }; + return Result; +} + +void *MipsJITInfo::emitFunctionStub(const Function* F, void *Fn, + JITCodeEmitter &JCE) { + JCE.emitAlignment(4); + void *Addr = (void*) (JCE.getCurrentPCValue()); + if (!sys::Memory::setRangeWritable(Addr, 16)) + llvm_unreachable("ERROR: Unable to mark stub writable."); + + intptr_t EmittedAddr; + if (Fn != (void*)(intptr_t)MipsCompilationCallback) + EmittedAddr = (intptr_t)Fn; + else + EmittedAddr = (intptr_t)MipsCompilationCallback; + + + int Hi = ((unsigned)EmittedAddr & 0xffff0000) >> 16; + if ((EmittedAddr & 0x8000) != 0) + Hi++; + int Lo = (int)(EmittedAddr & 0xffff); + + // lui t9, %hi(EmittedAddr) + // addiu t9, t9, %lo(EmittedAddr) + // jalr t8, t9 + // nop + JCE.emitWordLE(0xf << 26 | 25 << 16 | Hi); + JCE.emitWordLE(9 << 26 | 25 << 21 | 25 << 16 | Lo); + JCE.emitWordLE(25 << 21 | 24 << 11 | 9); + JCE.emitWordLE(0); + + sys::Memory::InvalidateInstructionCache(Addr, 16); + if (!sys::Memory::setRangeExecutable(Addr, 16)) + llvm_unreachable("ERROR: Unable to mark stub executable."); + + return Addr; +} + +/// 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 MipsJITInfo::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 ((Mips::RelocationType) MR->getRelocationType()) { + case Mips::reloc_mips_branch: + ResultPtr = (((ResultPtr - (intptr_t) RelocPos) - 4) >> 2) & 0xffff; + *((unsigned*) RelocPos) |= (unsigned) ResultPtr; + break; + + case Mips::reloc_mips_26: + ResultPtr = (ResultPtr & 0x0fffffff) >> 2; + *((unsigned*) RelocPos) |= (unsigned) ResultPtr; + break; + + case Mips::reloc_mips_hi: + ResultPtr = ResultPtr >> 16; + if ((((intptr_t) (MR->getResultPointer()) & 0xffff) >> 15) == 1) { + ResultPtr += 1; + } + *((unsigned*) RelocPos) |= (unsigned) ResultPtr; + break; + + case Mips::reloc_mips_lo: + ResultPtr = ResultPtr & 0xffff; + *((unsigned*) RelocPos) |= (unsigned) ResultPtr; + break; + + default: + llvm_unreachable("ERROR: Unknown Mips relocation."); + } + } +} |
