mirror of
https://github.com/c64scene-ar/llvm-6502.git
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30240 91177308-0d34-0410-b5e6-96231b3b80d8
1006 lines
38 KiB
C++
1006 lines
38 KiB
C++
//===-- JITEmitter.cpp - Write machine code to executable memory ----------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file was developed by the LLVM research group and is distributed under
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// the University of Illinois Open Source License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines a MachineCodeEmitter object that is used by the JIT to
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// write machine code to memory and remember where relocatable values are.
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//
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "jit"
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#include "JIT.h"
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#include "llvm/Constant.h"
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#include "llvm/Module.h"
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#include "llvm/Type.h"
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#include "llvm/CodeGen/MachineCodeEmitter.h"
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#include "llvm/CodeGen/MachineFunction.h"
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#include "llvm/CodeGen/MachineConstantPool.h"
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#include "llvm/CodeGen/MachineJumpTableInfo.h"
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#include "llvm/CodeGen/MachineRelocation.h"
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#include "llvm/ExecutionEngine/GenericValue.h"
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#include "llvm/Target/TargetData.h"
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#include "llvm/Target/TargetJITInfo.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/MutexGuard.h"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/System/Memory.h"
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#include <algorithm>
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#include <iostream>
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using namespace llvm;
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namespace {
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Statistic<> NumBytes("jit", "Number of bytes of machine code compiled");
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Statistic<> NumRelos("jit", "Number of relocations applied");
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JIT *TheJIT = 0;
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}
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//===----------------------------------------------------------------------===//
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// JITMemoryManager code.
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//
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namespace {
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/// MemoryRangeHeader - For a range of memory, this is the header that we put
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/// on the block of memory. It is carefully crafted to be one word of memory.
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/// Allocated blocks have just this header, free'd blocks have FreeRangeHeader
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/// which starts with this.
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struct FreeRangeHeader;
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struct MemoryRangeHeader {
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/// ThisAllocated - This is true if this block is currently allocated. If
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/// not, this can be converted to a FreeRangeHeader.
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intptr_t ThisAllocated : 1;
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/// PrevAllocated - Keep track of whether the block immediately before us is
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/// allocated. If not, the word immediately before this header is the size
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/// of the previous block.
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intptr_t PrevAllocated : 1;
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/// BlockSize - This is the size in bytes of this memory block,
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/// including this header.
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uintptr_t BlockSize : (sizeof(intptr_t)*8 - 2);
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/// getBlockAfter - Return the memory block immediately after this one.
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///
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MemoryRangeHeader &getBlockAfter() const {
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return *(MemoryRangeHeader*)((char*)this+BlockSize);
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}
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/// getFreeBlockBefore - If the block before this one is free, return it,
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/// otherwise return null.
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FreeRangeHeader *getFreeBlockBefore() const {
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if (PrevAllocated) return 0;
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intptr_t PrevSize = ((intptr_t *)this)[-1];
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return (FreeRangeHeader*)((char*)this-PrevSize);
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}
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/// FreeBlock - Turn an allocated block into a free block, adjusting
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/// bits in the object headers, and adding an end of region memory block.
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FreeRangeHeader *FreeBlock(FreeRangeHeader *FreeList);
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/// TrimAllocationToSize - If this allocated block is significantly larger
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/// than NewSize, split it into two pieces (where the former is NewSize
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/// bytes, including the header), and add the new block to the free list.
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FreeRangeHeader *TrimAllocationToSize(FreeRangeHeader *FreeList,
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uint64_t NewSize);
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};
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/// FreeRangeHeader - For a memory block that isn't already allocated, this
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/// keeps track of the current block and has a pointer to the next free block.
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/// Free blocks are kept on a circularly linked list.
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struct FreeRangeHeader : public MemoryRangeHeader {
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FreeRangeHeader *Prev;
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FreeRangeHeader *Next;
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/// getMinBlockSize - Get the minimum size for a memory block. Blocks
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/// smaller than this size cannot be created.
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static unsigned getMinBlockSize() {
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return sizeof(FreeRangeHeader)+sizeof(intptr_t);
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}
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/// SetEndOfBlockSizeMarker - The word at the end of every free block is
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/// known to be the size of the free block. Set it for this block.
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void SetEndOfBlockSizeMarker() {
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void *EndOfBlock = (char*)this + BlockSize;
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((intptr_t *)EndOfBlock)[-1] = BlockSize;
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}
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FreeRangeHeader *RemoveFromFreeList() {
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assert(Next->Prev == this && Prev->Next == this && "Freelist broken!");
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Next->Prev = Prev;
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return Prev->Next = Next;
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}
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void AddToFreeList(FreeRangeHeader *FreeList) {
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Next = FreeList;
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Prev = FreeList->Prev;
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Prev->Next = this;
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Next->Prev = this;
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}
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/// GrowBlock - The block after this block just got deallocated. Merge it
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/// into the current block.
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void GrowBlock(uintptr_t NewSize);
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/// AllocateBlock - Mark this entire block allocated, updating freelists
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/// etc. This returns a pointer to the circular free-list.
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FreeRangeHeader *AllocateBlock();
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};
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}
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/// AllocateBlock - Mark this entire block allocated, updating freelists
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/// etc. This returns a pointer to the circular free-list.
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FreeRangeHeader *FreeRangeHeader::AllocateBlock() {
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assert(!ThisAllocated && !getBlockAfter().PrevAllocated &&
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"Cannot allocate an allocated block!");
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// Mark this block allocated.
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ThisAllocated = 1;
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getBlockAfter().PrevAllocated = 1;
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// Remove it from the free list.
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return RemoveFromFreeList();
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}
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/// FreeBlock - Turn an allocated block into a free block, adjusting
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/// bits in the object headers, and adding an end of region memory block.
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/// If possible, coallesce this block with neighboring blocks. Return the
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/// FreeRangeHeader to allocate from.
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FreeRangeHeader *MemoryRangeHeader::FreeBlock(FreeRangeHeader *FreeList) {
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MemoryRangeHeader *FollowingBlock = &getBlockAfter();
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assert(ThisAllocated && "This block is already allocated!");
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assert(FollowingBlock->PrevAllocated && "Flags out of sync!");
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FreeRangeHeader *FreeListToReturn = FreeList;
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// If the block after this one is free, merge it into this block.
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if (!FollowingBlock->ThisAllocated) {
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FreeRangeHeader &FollowingFreeBlock = *(FreeRangeHeader *)FollowingBlock;
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// "FreeList" always needs to be a valid free block. If we're about to
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// coallesce with it, update our notion of what the free list is.
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if (&FollowingFreeBlock == FreeList) {
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FreeList = FollowingFreeBlock.Next;
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FreeListToReturn = 0;
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assert(&FollowingFreeBlock != FreeList && "No tombstone block?");
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}
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FollowingFreeBlock.RemoveFromFreeList();
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// Include the following block into this one.
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BlockSize += FollowingFreeBlock.BlockSize;
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FollowingBlock = &FollowingFreeBlock.getBlockAfter();
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// Tell the block after the block we are coallescing that this block is
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// allocated.
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FollowingBlock->PrevAllocated = 1;
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}
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assert(FollowingBlock->ThisAllocated && "Missed coallescing?");
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if (FreeRangeHeader *PrevFreeBlock = getFreeBlockBefore()) {
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PrevFreeBlock->GrowBlock(PrevFreeBlock->BlockSize + BlockSize);
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return FreeListToReturn ? FreeListToReturn : PrevFreeBlock;
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}
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// Otherwise, mark this block free.
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FreeRangeHeader &FreeBlock = *(FreeRangeHeader*)this;
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FollowingBlock->PrevAllocated = 0;
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FreeBlock.ThisAllocated = 0;
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// Link this into the linked list of free blocks.
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FreeBlock.AddToFreeList(FreeList);
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// Add a marker at the end of the block, indicating the size of this free
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// block.
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FreeBlock.SetEndOfBlockSizeMarker();
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return FreeListToReturn ? FreeListToReturn : &FreeBlock;
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}
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/// GrowBlock - The block after this block just got deallocated. Merge it
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/// into the current block.
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void FreeRangeHeader::GrowBlock(uintptr_t NewSize) {
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assert(NewSize > BlockSize && "Not growing block?");
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BlockSize = NewSize;
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SetEndOfBlockSizeMarker();
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getBlockAfter().PrevAllocated = 0;
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}
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/// TrimAllocationToSize - If this allocated block is significantly larger
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/// than NewSize, split it into two pieces (where the former is NewSize
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/// bytes, including the header), and add the new block to the free list.
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FreeRangeHeader *MemoryRangeHeader::
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TrimAllocationToSize(FreeRangeHeader *FreeList, uint64_t NewSize) {
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assert(ThisAllocated && getBlockAfter().PrevAllocated &&
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"Cannot deallocate part of an allocated block!");
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// Round up size for alignment of header.
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unsigned HeaderAlign = __alignof(FreeRangeHeader);
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NewSize = (NewSize+ (HeaderAlign-1)) & ~(HeaderAlign-1);
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// Size is now the size of the block we will remove from the start of the
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// current block.
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assert(NewSize <= BlockSize &&
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"Allocating more space from this block than exists!");
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// If splitting this block will cause the remainder to be too small, do not
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// split the block.
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if (BlockSize <= NewSize+FreeRangeHeader::getMinBlockSize())
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return FreeList;
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// Otherwise, we splice the required number of bytes out of this block, form
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// a new block immediately after it, then mark this block allocated.
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MemoryRangeHeader &FormerNextBlock = getBlockAfter();
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// Change the size of this block.
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BlockSize = NewSize;
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// Get the new block we just sliced out and turn it into a free block.
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FreeRangeHeader &NewNextBlock = (FreeRangeHeader &)getBlockAfter();
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NewNextBlock.BlockSize = (char*)&FormerNextBlock - (char*)&NewNextBlock;
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NewNextBlock.ThisAllocated = 0;
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NewNextBlock.PrevAllocated = 1;
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NewNextBlock.SetEndOfBlockSizeMarker();
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FormerNextBlock.PrevAllocated = 0;
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NewNextBlock.AddToFreeList(FreeList);
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return &NewNextBlock;
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}
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namespace {
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/// JITMemoryManager - Manage memory for the JIT code generation in a logical,
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/// sane way. This splits a large block of MAP_NORESERVE'd memory into two
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/// sections, one for function stubs, one for the functions themselves. We
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/// have to do this because we may need to emit a function stub while in the
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/// middle of emitting a function, and we don't know how large the function we
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/// are emitting is. This never bothers to release the memory, because when
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/// we are ready to destroy the JIT, the program exits.
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class JITMemoryManager {
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std::vector<sys::MemoryBlock> Blocks; // Memory blocks allocated by the JIT
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FreeRangeHeader *FreeMemoryList; // Circular list of free blocks.
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// When emitting code into a memory block, this is the block.
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MemoryRangeHeader *CurBlock;
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unsigned char *CurStubPtr, *StubBase;
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unsigned char *GOTBase; // Target Specific reserved memory
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// Centralize memory block allocation.
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sys::MemoryBlock getNewMemoryBlock(unsigned size);
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std::map<const Function*, MemoryRangeHeader*> FunctionBlocks;
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public:
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JITMemoryManager(bool useGOT);
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~JITMemoryManager();
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inline unsigned char *allocateStub(unsigned StubSize);
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/// startFunctionBody - When a function starts, allocate a block of free
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/// executable memory, returning a pointer to it and its actual size.
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unsigned char *startFunctionBody(uintptr_t &ActualSize) {
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CurBlock = FreeMemoryList;
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// Allocate the entire memory block.
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FreeMemoryList = FreeMemoryList->AllocateBlock();
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ActualSize = CurBlock->BlockSize-sizeof(MemoryRangeHeader);
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return (unsigned char *)(CurBlock+1);
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}
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/// endFunctionBody - The function F is now allocated, and takes the memory
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/// in the range [FunctionStart,FunctionEnd).
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void endFunctionBody(const Function *F, unsigned char *FunctionStart,
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unsigned char *FunctionEnd) {
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assert(FunctionEnd > FunctionStart);
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assert(FunctionStart == (unsigned char *)(CurBlock+1) &&
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"Mismatched function start/end!");
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uintptr_t BlockSize = FunctionEnd - (unsigned char *)CurBlock;
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FunctionBlocks[F] = CurBlock;
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// Release the memory at the end of this block that isn't needed.
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FreeMemoryList =CurBlock->TrimAllocationToSize(FreeMemoryList, BlockSize);
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}
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unsigned char *getGOTBase() const {
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return GOTBase;
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}
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bool isManagingGOT() const {
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return GOTBase != NULL;
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}
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/// deallocateMemForFunction - Deallocate all memory for the specified
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/// function body.
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void deallocateMemForFunction(const Function *F) {
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std::map<const Function*, MemoryRangeHeader*>::iterator
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I = FunctionBlocks.find(F);
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if (I == FunctionBlocks.end()) return;
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// Find the block that is allocated for this function.
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MemoryRangeHeader *MemRange = I->second;
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assert(MemRange->ThisAllocated && "Block isn't allocated!");
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// Fill the buffer with garbage!
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DEBUG(memset(MemRange+1, 0xCD, MemRange->BlockSize-sizeof(*MemRange)));
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// Free the memory.
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FreeMemoryList = MemRange->FreeBlock(FreeMemoryList);
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// Finally, remove this entry from FunctionBlocks.
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FunctionBlocks.erase(I);
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}
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};
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}
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JITMemoryManager::JITMemoryManager(bool useGOT) {
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// Allocate a 16M block of memory for functions.
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sys::MemoryBlock MemBlock = getNewMemoryBlock(16 << 20);
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unsigned char *MemBase = reinterpret_cast<unsigned char*>(MemBlock.base());
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// Allocate stubs backwards from the base, allocate functions forward
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// from the base.
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StubBase = MemBase;
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CurStubPtr = MemBase + 512*1024; // Use 512k for stubs, working backwards.
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// We set up the memory chunk with 4 mem regions, like this:
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// [ START
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// [ Free #0 ] -> Large space to allocate functions from.
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// [ Allocated #1 ] -> Tiny space to separate regions.
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// [ Free #2 ] -> Tiny space so there is always at least 1 free block.
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// [ Allocated #3 ] -> Tiny space to prevent looking past end of block.
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// END ]
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//
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// The last three blocks are never deallocated or touched.
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// Add MemoryRangeHeader to the end of the memory region, indicating that
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// the space after the block of memory is allocated. This is block #3.
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MemoryRangeHeader *Mem3 = (MemoryRangeHeader*)(MemBase+MemBlock.size())-1;
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Mem3->ThisAllocated = 1;
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Mem3->PrevAllocated = 0;
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Mem3->BlockSize = 0;
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/// Add a tiny free region so that the free list always has one entry.
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FreeRangeHeader *Mem2 =
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(FreeRangeHeader *)(((char*)Mem3)-FreeRangeHeader::getMinBlockSize());
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Mem2->ThisAllocated = 0;
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Mem2->PrevAllocated = 1;
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Mem2->BlockSize = FreeRangeHeader::getMinBlockSize();
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Mem2->SetEndOfBlockSizeMarker();
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Mem2->Prev = Mem2; // Mem2 *is* the free list for now.
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Mem2->Next = Mem2;
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/// Add a tiny allocated region so that Mem2 is never coallesced away.
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MemoryRangeHeader *Mem1 = (MemoryRangeHeader*)Mem2-1;
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Mem1->ThisAllocated = 1;
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Mem1->PrevAllocated = 0;
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Mem1->BlockSize = (char*)Mem2 - (char*)Mem1;
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// Add a FreeRangeHeader to the start of the function body region, indicating
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// that the space is free. Mark the previous block allocated so we never look
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// at it.
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FreeRangeHeader *Mem0 = (FreeRangeHeader*)CurStubPtr;
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Mem0->ThisAllocated = 0;
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Mem0->PrevAllocated = 1;
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Mem0->BlockSize = (char*)Mem1-(char*)Mem0;
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Mem0->SetEndOfBlockSizeMarker();
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Mem0->AddToFreeList(Mem2);
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// Start out with the freelist pointing to Mem0.
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FreeMemoryList = Mem0;
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// Allocate the GOT.
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GOTBase = NULL;
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if (useGOT) GOTBase = new unsigned char[sizeof(void*) * 8192];
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}
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JITMemoryManager::~JITMemoryManager() {
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for (unsigned i = 0, e = Blocks.size(); i != e; ++i)
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sys::Memory::ReleaseRWX(Blocks[i]);
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delete[] GOTBase;
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Blocks.clear();
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}
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unsigned char *JITMemoryManager::allocateStub(unsigned StubSize) {
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CurStubPtr -= StubSize;
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if (CurStubPtr < StubBase) {
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// FIXME: allocate a new block
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std::cerr << "JIT ran out of memory for function stubs!\n";
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abort();
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}
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return CurStubPtr;
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}
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sys::MemoryBlock JITMemoryManager::getNewMemoryBlock(unsigned size) {
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// Allocate a new block close to the last one.
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const sys::MemoryBlock *BOld = Blocks.empty() ? 0 : &Blocks.front();
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std::string ErrMsg;
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sys::MemoryBlock B = sys::Memory::AllocateRWX(size, BOld, &ErrMsg);
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if (B.base() == 0) {
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std::cerr << "Allocation failed when allocating new memory in the JIT\n";
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std::cerr << ErrMsg << "\n";
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abort();
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}
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Blocks.push_back(B);
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return B;
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}
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//===----------------------------------------------------------------------===//
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// JIT lazy compilation code.
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//
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namespace {
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class JITResolverState {
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private:
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/// FunctionToStubMap - Keep track of the stub created for a particular
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/// function so that we can reuse them if necessary.
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std::map<Function*, void*> FunctionToStubMap;
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/// StubToFunctionMap - Keep track of the function that each stub
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/// corresponds to.
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std::map<void*, Function*> StubToFunctionMap;
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public:
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std::map<Function*, void*>& getFunctionToStubMap(const MutexGuard& locked) {
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assert(locked.holds(TheJIT->lock));
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return FunctionToStubMap;
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}
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std::map<void*, Function*>& getStubToFunctionMap(const MutexGuard& locked) {
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assert(locked.holds(TheJIT->lock));
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return StubToFunctionMap;
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}
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};
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/// JITResolver - Keep track of, and resolve, call sites for functions that
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/// have not yet been compiled.
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class JITResolver {
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/// MCE - The MachineCodeEmitter to use to emit stubs with.
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MachineCodeEmitter &MCE;
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/// LazyResolverFn - The target lazy resolver function that we actually
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/// rewrite instructions to use.
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TargetJITInfo::LazyResolverFn LazyResolverFn;
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JITResolverState state;
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/// ExternalFnToStubMap - This is the equivalent of FunctionToStubMap for
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/// external functions.
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std::map<void*, void*> ExternalFnToStubMap;
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//map addresses to indexes in the GOT
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std::map<void*, unsigned> revGOTMap;
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unsigned nextGOTIndex;
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public:
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JITResolver(MachineCodeEmitter &mce) : MCE(mce), nextGOTIndex(0) {
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LazyResolverFn =
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TheJIT->getJITInfo().getLazyResolverFunction(JITCompilerFn);
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}
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/// getFunctionStub - This returns a pointer to a function stub, creating
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/// one on demand as needed.
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void *getFunctionStub(Function *F);
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/// getExternalFunctionStub - Return a stub for the function at the
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/// specified address, created lazily on demand.
|
|
void *getExternalFunctionStub(void *FnAddr);
|
|
|
|
/// AddCallbackAtLocation - If the target is capable of rewriting an
|
|
/// instruction without the use of a stub, record the location of the use so
|
|
/// we know which function is being used at the location.
|
|
void *AddCallbackAtLocation(Function *F, void *Location) {
|
|
MutexGuard locked(TheJIT->lock);
|
|
/// Get the target-specific JIT resolver function.
|
|
state.getStubToFunctionMap(locked)[Location] = F;
|
|
return (void*)(intptr_t)LazyResolverFn;
|
|
}
|
|
|
|
/// getGOTIndexForAddress - Return a new or existing index in the GOT for
|
|
/// and address. This function only manages slots, it does not manage the
|
|
/// contents of the slots or the memory associated with the GOT.
|
|
unsigned getGOTIndexForAddr(void* addr);
|
|
|
|
/// JITCompilerFn - This function is called to resolve a stub to a compiled
|
|
/// address. If the LLVM Function corresponding to the stub has not yet
|
|
/// been compiled, this function compiles it first.
|
|
static void *JITCompilerFn(void *Stub);
|
|
};
|
|
}
|
|
|
|
/// getJITResolver - This function returns the one instance of the JIT resolver.
|
|
///
|
|
static JITResolver &getJITResolver(MachineCodeEmitter *MCE = 0) {
|
|
static JITResolver TheJITResolver(*MCE);
|
|
return TheJITResolver;
|
|
}
|
|
|
|
#if (defined(__POWERPC__) || defined (__ppc__) || defined(_POWER)) && \
|
|
defined(__APPLE__)
|
|
extern "C" void sys_icache_invalidate(const void *Addr, size_t len);
|
|
#endif
|
|
|
|
/// synchronizeICache - On some targets, the JIT emitted code must be
|
|
/// explicitly refetched to ensure correct execution.
|
|
static void synchronizeICache(const void *Addr, size_t len) {
|
|
#if (defined(__POWERPC__) || defined (__ppc__) || defined(_POWER)) && \
|
|
defined(__APPLE__)
|
|
sys_icache_invalidate(Addr, len);
|
|
#endif
|
|
}
|
|
|
|
/// getFunctionStub - This returns a pointer to a function stub, creating
|
|
/// one on demand as needed.
|
|
void *JITResolver::getFunctionStub(Function *F) {
|
|
MutexGuard locked(TheJIT->lock);
|
|
|
|
// If we already have a stub for this function, recycle it.
|
|
void *&Stub = state.getFunctionToStubMap(locked)[F];
|
|
if (Stub) return Stub;
|
|
|
|
// Call the lazy resolver function unless we already KNOW it is an external
|
|
// function, in which case we just skip the lazy resolution step.
|
|
void *Actual = (void*)(intptr_t)LazyResolverFn;
|
|
if (F->isExternal() && F->hasExternalLinkage())
|
|
Actual = TheJIT->getPointerToFunction(F);
|
|
|
|
// Otherwise, codegen a new stub. For now, the stub will call the lazy
|
|
// resolver function.
|
|
Stub = TheJIT->getJITInfo().emitFunctionStub(Actual, MCE);
|
|
|
|
if (Actual != (void*)(intptr_t)LazyResolverFn) {
|
|
// If we are getting the stub for an external function, we really want the
|
|
// address of the stub in the GlobalAddressMap for the JIT, not the address
|
|
// of the external function.
|
|
TheJIT->updateGlobalMapping(F, Stub);
|
|
}
|
|
|
|
// Invalidate the icache if necessary.
|
|
synchronizeICache(Stub, MCE.getCurrentPCValue()-(intptr_t)Stub);
|
|
|
|
DEBUG(std::cerr << "JIT: Stub emitted at [" << Stub << "] for function '"
|
|
<< F->getName() << "'\n");
|
|
|
|
// Finally, keep track of the stub-to-Function mapping so that the
|
|
// JITCompilerFn knows which function to compile!
|
|
state.getStubToFunctionMap(locked)[Stub] = F;
|
|
return Stub;
|
|
}
|
|
|
|
/// getExternalFunctionStub - Return a stub for the function at the
|
|
/// specified address, created lazily on demand.
|
|
void *JITResolver::getExternalFunctionStub(void *FnAddr) {
|
|
// If we already have a stub for this function, recycle it.
|
|
void *&Stub = ExternalFnToStubMap[FnAddr];
|
|
if (Stub) return Stub;
|
|
|
|
Stub = TheJIT->getJITInfo().emitFunctionStub(FnAddr, MCE);
|
|
|
|
// Invalidate the icache if necessary.
|
|
synchronizeICache(Stub, MCE.getCurrentPCValue()-(intptr_t)Stub);
|
|
|
|
DEBUG(std::cerr << "JIT: Stub emitted at [" << Stub
|
|
<< "] for external function at '" << FnAddr << "'\n");
|
|
return Stub;
|
|
}
|
|
|
|
unsigned JITResolver::getGOTIndexForAddr(void* addr) {
|
|
unsigned idx = revGOTMap[addr];
|
|
if (!idx) {
|
|
idx = ++nextGOTIndex;
|
|
revGOTMap[addr] = idx;
|
|
DEBUG(std::cerr << "Adding GOT entry " << idx
|
|
<< " for addr " << addr << "\n");
|
|
// ((void**)MemMgr.getGOTBase())[idx] = addr;
|
|
}
|
|
return idx;
|
|
}
|
|
|
|
/// JITCompilerFn - This function is called when a lazy compilation stub has
|
|
/// been entered. It looks up which function this stub corresponds to, compiles
|
|
/// it if necessary, then returns the resultant function pointer.
|
|
void *JITResolver::JITCompilerFn(void *Stub) {
|
|
JITResolver &JR = getJITResolver();
|
|
|
|
MutexGuard locked(TheJIT->lock);
|
|
|
|
// The address given to us for the stub may not be exactly right, it might be
|
|
// a little bit after the stub. As such, use upper_bound to find it.
|
|
std::map<void*, Function*>::iterator I =
|
|
JR.state.getStubToFunctionMap(locked).upper_bound(Stub);
|
|
assert(I != JR.state.getStubToFunctionMap(locked).begin() &&
|
|
"This is not a known stub!");
|
|
Function *F = (--I)->second;
|
|
|
|
// We might like to remove the stub from the StubToFunction map.
|
|
// We can't do that! Multiple threads could be stuck, waiting to acquire the
|
|
// lock above. As soon as the 1st function finishes compiling the function,
|
|
// the next one will be released, and needs to be able to find the function it
|
|
// needs to call.
|
|
//JR.state.getStubToFunctionMap(locked).erase(I);
|
|
|
|
DEBUG(std::cerr << "JIT: Lazily resolving function '" << F->getName()
|
|
<< "' In stub ptr = " << Stub << " actual ptr = "
|
|
<< I->first << "\n");
|
|
|
|
void *Result = TheJIT->getPointerToFunction(F);
|
|
|
|
// We don't need to reuse this stub in the future, as F is now compiled.
|
|
JR.state.getFunctionToStubMap(locked).erase(F);
|
|
|
|
// FIXME: We could rewrite all references to this stub if we knew them.
|
|
|
|
// What we will do is set the compiled function address to map to the
|
|
// same GOT entry as the stub so that later clients may update the GOT
|
|
// if they see it still using the stub address.
|
|
// Note: this is done so the Resolver doesn't have to manage GOT memory
|
|
// Do this without allocating map space if the target isn't using a GOT
|
|
if(JR.revGOTMap.find(Stub) != JR.revGOTMap.end())
|
|
JR.revGOTMap[Result] = JR.revGOTMap[Stub];
|
|
|
|
return Result;
|
|
}
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// JITEmitter code.
|
|
//
|
|
namespace {
|
|
/// JITEmitter - The JIT implementation of the MachineCodeEmitter, which is
|
|
/// used to output functions to memory for execution.
|
|
class JITEmitter : public MachineCodeEmitter {
|
|
JITMemoryManager MemMgr;
|
|
|
|
// When outputting a function stub in the context of some other function, we
|
|
// save BufferBegin/BufferEnd/CurBufferPtr here.
|
|
unsigned char *SavedBufferBegin, *SavedBufferEnd, *SavedCurBufferPtr;
|
|
|
|
/// Relocations - These are the relocations that the function needs, as
|
|
/// emitted.
|
|
std::vector<MachineRelocation> Relocations;
|
|
|
|
/// MBBLocations - This vector is a mapping from MBB ID's to their address.
|
|
/// It is filled in by the StartMachineBasicBlock callback and queried by
|
|
/// the getMachineBasicBlockAddress callback.
|
|
std::vector<intptr_t> MBBLocations;
|
|
|
|
/// ConstantPool - The constant pool for the current function.
|
|
///
|
|
MachineConstantPool *ConstantPool;
|
|
|
|
/// ConstantPoolBase - A pointer to the first entry in the constant pool.
|
|
///
|
|
void *ConstantPoolBase;
|
|
|
|
/// JumpTable - The jump tables for the current function.
|
|
///
|
|
MachineJumpTableInfo *JumpTable;
|
|
|
|
/// JumpTableBase - A pointer to the first entry in the jump table.
|
|
///
|
|
void *JumpTableBase;
|
|
public:
|
|
JITEmitter(JIT &jit) : MemMgr(jit.getJITInfo().needsGOT()) {
|
|
TheJIT = &jit;
|
|
DEBUG(if (MemMgr.isManagingGOT()) std::cerr << "JIT is managing a GOT\n");
|
|
}
|
|
|
|
virtual void startFunction(MachineFunction &F);
|
|
virtual bool finishFunction(MachineFunction &F);
|
|
|
|
void emitConstantPool(MachineConstantPool *MCP);
|
|
void initJumpTableInfo(MachineJumpTableInfo *MJTI);
|
|
void emitJumpTableInfo(MachineJumpTableInfo *MJTI);
|
|
|
|
virtual void startFunctionStub(unsigned StubSize);
|
|
virtual void* finishFunctionStub(const Function *F);
|
|
|
|
virtual void addRelocation(const MachineRelocation &MR) {
|
|
Relocations.push_back(MR);
|
|
}
|
|
|
|
virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
|
|
if (MBBLocations.size() <= (unsigned)MBB->getNumber())
|
|
MBBLocations.resize((MBB->getNumber()+1)*2);
|
|
MBBLocations[MBB->getNumber()] = getCurrentPCValue();
|
|
}
|
|
|
|
virtual intptr_t getConstantPoolEntryAddress(unsigned Entry) const;
|
|
virtual intptr_t getJumpTableEntryAddress(unsigned Entry) const;
|
|
|
|
virtual intptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
|
|
assert(MBBLocations.size() > (unsigned)MBB->getNumber() &&
|
|
MBBLocations[MBB->getNumber()] && "MBB not emitted!");
|
|
return MBBLocations[MBB->getNumber()];
|
|
}
|
|
|
|
/// deallocateMemForFunction - Deallocate all memory for the specified
|
|
/// function body.
|
|
void deallocateMemForFunction(Function *F) {
|
|
MemMgr.deallocateMemForFunction(F);
|
|
}
|
|
private:
|
|
void *getPointerToGlobal(GlobalValue *GV, void *Reference, bool NoNeedStub);
|
|
};
|
|
}
|
|
|
|
void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
|
|
bool DoesntNeedStub) {
|
|
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
|
|
/// FIXME: If we straightened things out, this could actually emit the
|
|
/// global immediately instead of queuing it for codegen later!
|
|
return TheJIT->getOrEmitGlobalVariable(GV);
|
|
}
|
|
|
|
// If we have already compiled the function, return a pointer to its body.
|
|
Function *F = cast<Function>(V);
|
|
void *ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
|
|
if (ResultPtr) return ResultPtr;
|
|
|
|
if (F->hasExternalLinkage() && F->isExternal()) {
|
|
// If this is an external function pointer, we can force the JIT to
|
|
// 'compile' it, which really just adds it to the map.
|
|
if (DoesntNeedStub)
|
|
return TheJIT->getPointerToFunction(F);
|
|
|
|
return getJITResolver(this).getFunctionStub(F);
|
|
}
|
|
|
|
// Okay, the function has not been compiled yet, if the target callback
|
|
// mechanism is capable of rewriting the instruction directly, prefer to do
|
|
// that instead of emitting a stub.
|
|
if (DoesntNeedStub)
|
|
return getJITResolver(this).AddCallbackAtLocation(F, Reference);
|
|
|
|
// Otherwise, we have to emit a lazy resolving stub.
|
|
return getJITResolver(this).getFunctionStub(F);
|
|
}
|
|
|
|
void JITEmitter::startFunction(MachineFunction &F) {
|
|
uintptr_t ActualSize;
|
|
BufferBegin = CurBufferPtr = MemMgr.startFunctionBody(ActualSize);
|
|
BufferEnd = BufferBegin+ActualSize;
|
|
|
|
emitConstantPool(F.getConstantPool());
|
|
initJumpTableInfo(F.getJumpTableInfo());
|
|
|
|
// About to start emitting the machine code for the function.
|
|
emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
|
|
TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr);
|
|
|
|
MBBLocations.clear();
|
|
}
|
|
|
|
bool JITEmitter::finishFunction(MachineFunction &F) {
|
|
if (CurBufferPtr == BufferEnd) {
|
|
// FIXME: Allocate more space, then try again.
|
|
std::cerr << "JIT: Ran out of space for generated machine code!\n";
|
|
abort();
|
|
}
|
|
|
|
emitJumpTableInfo(F.getJumpTableInfo());
|
|
|
|
// FnStart is the start of the text, not the start of the constant pool and
|
|
// other per-function data.
|
|
unsigned char *FnStart =
|
|
(unsigned char *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
|
|
unsigned char *FnEnd = CurBufferPtr;
|
|
|
|
MemMgr.endFunctionBody(F.getFunction(), BufferBegin, FnEnd);
|
|
NumBytes += FnEnd-FnStart;
|
|
|
|
if (!Relocations.empty()) {
|
|
NumRelos += Relocations.size();
|
|
|
|
// Resolve the relocations to concrete pointers.
|
|
for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
|
|
MachineRelocation &MR = Relocations[i];
|
|
void *ResultPtr;
|
|
if (MR.isString()) {
|
|
ResultPtr = TheJIT->getPointerToNamedFunction(MR.getString());
|
|
|
|
// If the target REALLY wants a stub for this function, emit it now.
|
|
if (!MR.doesntNeedFunctionStub())
|
|
ResultPtr = getJITResolver(this).getExternalFunctionStub(ResultPtr);
|
|
} else if (MR.isGlobalValue()) {
|
|
ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
|
|
BufferBegin+MR.getMachineCodeOffset(),
|
|
MR.doesntNeedFunctionStub());
|
|
} else if (MR.isBasicBlock()) {
|
|
ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
|
|
} else if (MR.isConstantPoolIndex()){
|
|
ResultPtr=(void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex());
|
|
} else {
|
|
assert(MR.isJumpTableIndex());
|
|
ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex());
|
|
}
|
|
|
|
MR.setResultPointer(ResultPtr);
|
|
|
|
// if we are managing the GOT and the relocation wants an index,
|
|
// give it one
|
|
if (MemMgr.isManagingGOT() && MR.isGOTRelative()) {
|
|
unsigned idx = getJITResolver(this).getGOTIndexForAddr(ResultPtr);
|
|
MR.setGOTIndex(idx);
|
|
if (((void**)MemMgr.getGOTBase())[idx] != ResultPtr) {
|
|
DEBUG(std::cerr << "GOT was out of date for " << ResultPtr
|
|
<< " pointing at " << ((void**)MemMgr.getGOTBase())[idx]
|
|
<< "\n");
|
|
((void**)MemMgr.getGOTBase())[idx] = ResultPtr;
|
|
}
|
|
}
|
|
}
|
|
|
|
TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
|
|
Relocations.size(), MemMgr.getGOTBase());
|
|
}
|
|
|
|
// Update the GOT entry for F to point to the new code.
|
|
if(MemMgr.isManagingGOT()) {
|
|
unsigned idx = getJITResolver(this).getGOTIndexForAddr((void*)BufferBegin);
|
|
if (((void**)MemMgr.getGOTBase())[idx] != (void*)BufferBegin) {
|
|
DEBUG(std::cerr << "GOT was out of date for " << (void*)BufferBegin
|
|
<< " pointing at " << ((void**)MemMgr.getGOTBase())[idx] << "\n");
|
|
((void**)MemMgr.getGOTBase())[idx] = (void*)BufferBegin;
|
|
}
|
|
}
|
|
|
|
// Invalidate the icache if necessary.
|
|
synchronizeICache(FnStart, FnEnd-FnStart);
|
|
|
|
DEBUG(std::cerr << "JIT: Finished CodeGen of [" << (void*)FnStart
|
|
<< "] Function: " << F.getFunction()->getName()
|
|
<< ": " << (FnEnd-FnStart) << " bytes of text, "
|
|
<< Relocations.size() << " relocations\n");
|
|
Relocations.clear();
|
|
return false;
|
|
}
|
|
|
|
void JITEmitter::emitConstantPool(MachineConstantPool *MCP) {
|
|
const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
|
|
if (Constants.empty()) return;
|
|
|
|
unsigned Size = Constants.back().Offset;
|
|
Size += TheJIT->getTargetData()->getTypeSize(Constants.back().Val->getType());
|
|
|
|
ConstantPoolBase = allocateSpace(Size, 1 << MCP->getConstantPoolAlignment());
|
|
ConstantPool = MCP;
|
|
|
|
if (ConstantPoolBase == 0) return; // Buffer overflow.
|
|
|
|
// Initialize the memory for all of the constant pool entries.
|
|
for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
|
|
void *CAddr = (char*)ConstantPoolBase+Constants[i].Offset;
|
|
TheJIT->InitializeMemory(Constants[i].Val, CAddr);
|
|
}
|
|
}
|
|
|
|
void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
|
|
const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
|
|
if (JT.empty()) return;
|
|
|
|
unsigned NumEntries = 0;
|
|
for (unsigned i = 0, e = JT.size(); i != e; ++i)
|
|
NumEntries += JT[i].MBBs.size();
|
|
|
|
unsigned EntrySize = MJTI->getEntrySize();
|
|
|
|
// Just allocate space for all the jump tables now. We will fix up the actual
|
|
// MBB entries in the tables after we emit the code for each block, since then
|
|
// we will know the final locations of the MBBs in memory.
|
|
JumpTable = MJTI;
|
|
JumpTableBase = allocateSpace(NumEntries * EntrySize, MJTI->getAlignment());
|
|
}
|
|
|
|
void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
|
|
const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
|
|
if (JT.empty() || JumpTableBase == 0) return;
|
|
|
|
unsigned Offset = 0;
|
|
assert(MJTI->getEntrySize() == sizeof(void*) && "Cross JIT'ing?");
|
|
|
|
// For each jump table, map each target in the jump table to the address of
|
|
// an emitted MachineBasicBlock.
|
|
intptr_t *SlotPtr = (intptr_t*)JumpTableBase;
|
|
|
|
for (unsigned i = 0, e = JT.size(); i != e; ++i) {
|
|
const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
|
|
// Store the address of the basic block for this jump table slot in the
|
|
// memory we allocated for the jump table in 'initJumpTableInfo'
|
|
for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
|
|
*SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]);
|
|
}
|
|
}
|
|
|
|
void JITEmitter::startFunctionStub(unsigned StubSize) {
|
|
SavedBufferBegin = BufferBegin;
|
|
SavedBufferEnd = BufferEnd;
|
|
SavedCurBufferPtr = CurBufferPtr;
|
|
|
|
BufferBegin = CurBufferPtr = MemMgr.allocateStub(StubSize);
|
|
BufferEnd = BufferBegin+StubSize+1;
|
|
}
|
|
|
|
void *JITEmitter::finishFunctionStub(const Function *F) {
|
|
NumBytes += getCurrentPCOffset();
|
|
std::swap(SavedBufferBegin, BufferBegin);
|
|
BufferEnd = SavedBufferEnd;
|
|
CurBufferPtr = SavedCurBufferPtr;
|
|
return SavedBufferBegin;
|
|
}
|
|
|
|
// getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry
|
|
// in the constant pool that was last emitted with the 'emitConstantPool'
|
|
// method.
|
|
//
|
|
intptr_t JITEmitter::getConstantPoolEntryAddress(unsigned ConstantNum) const {
|
|
assert(ConstantNum < ConstantPool->getConstants().size() &&
|
|
"Invalid ConstantPoolIndex!");
|
|
return (intptr_t)ConstantPoolBase +
|
|
ConstantPool->getConstants()[ConstantNum].Offset;
|
|
}
|
|
|
|
// getJumpTableEntryAddress - Return the address of the JumpTable with index
|
|
// 'Index' in the jumpp table that was last initialized with 'initJumpTableInfo'
|
|
//
|
|
intptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const {
|
|
const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables();
|
|
assert(Index < JT.size() && "Invalid jump table index!");
|
|
|
|
unsigned Offset = 0;
|
|
unsigned EntrySize = JumpTable->getEntrySize();
|
|
|
|
for (unsigned i = 0; i < Index; ++i)
|
|
Offset += JT[i].MBBs.size() * EntrySize;
|
|
|
|
return (intptr_t)((char *)JumpTableBase + Offset);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Public interface to this file
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
MachineCodeEmitter *JIT::createEmitter(JIT &jit) {
|
|
return new JITEmitter(jit);
|
|
}
|
|
|
|
// getPointerToNamedFunction - This function is used as a global wrapper to
|
|
// JIT::getPointerToNamedFunction for the purpose of resolving symbols when
|
|
// bugpoint is debugging the JIT. In that scenario, we are loading an .so and
|
|
// need to resolve function(s) that are being mis-codegenerated, so we need to
|
|
// resolve their addresses at runtime, and this is the way to do it.
|
|
extern "C" {
|
|
void *getPointerToNamedFunction(const char *Name) {
|
|
if (Function *F = TheJIT->FindFunctionNamed(Name))
|
|
return TheJIT->getPointerToFunction(F);
|
|
return TheJIT->getPointerToNamedFunction(Name);
|
|
}
|
|
}
|
|
|
|
// getPointerToFunctionOrStub - If the specified function has been
|
|
// code-gen'd, return a pointer to the function. If not, compile it, or use
|
|
// a stub to implement lazy compilation if available.
|
|
//
|
|
void *JIT::getPointerToFunctionOrStub(Function *F) {
|
|
// If we have already code generated the function, just return the address.
|
|
if (void *Addr = getPointerToGlobalIfAvailable(F))
|
|
return Addr;
|
|
|
|
// Get a stub if the target supports it
|
|
return getJITResolver(MCE).getFunctionStub(F);
|
|
}
|
|
|
|
/// freeMachineCodeForFunction - release machine code memory for given Function.
|
|
///
|
|
void JIT::freeMachineCodeForFunction(Function *F) {
|
|
// Delete translation for this from the ExecutionEngine, so it will get
|
|
// retranslated next time it is used.
|
|
updateGlobalMapping(F, 0);
|
|
|
|
// Free the actual memory for the function body and related stuff.
|
|
assert(dynamic_cast<JITEmitter*>(MCE) && "Unexpected MCE?");
|
|
dynamic_cast<JITEmitter*>(MCE)->deallocateMemForFunction(F);
|
|
}
|
|
|