Author: lattner
Date: Wed Dec 5 17:39:57 2007
New Revision: 44640
URL: http://llvm.org/viewvc/llvm-project?rev=44640&view=rev
Log:
split the JIT memory management code out from the main JIT logic into its
own JITMemoryManager interface. There is no functionality change with
this patch.
Added:
llvm/trunk/include/llvm/ExecutionEngine/JITMemoryManager.h
llvm/trunk/lib/ExecutionEngine/JIT/JITMemoryManager.cpp
Modified:
llvm/trunk/include/llvm/ExecutionEngine/JIT.h
llvm/trunk/lib/ExecutionEngine/JIT/JITEmitter.cpp
Modified: llvm/trunk/include/llvm/ExecutionEngine/JIT.h
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ExecutionEngine/JIT.h?rev=44640&r1=44639&r2=44640&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ExecutionEngine/JIT.h (original)
+++ llvm/trunk/include/llvm/ExecutionEngine/JIT.h Wed Dec 5 17:39:57 2007
@@ -12,8 +12,8 @@
//
//===----------------------------------------------------------------------===//
-#ifndef EXECUTION_ENGINE_JIT_H
-#define EXECUTION_ENGINE_JIT_H
+#ifndef LLVM_EXECUTION_ENGINE_JIT_H
+#define LLVM_EXECUTION_ENGINE_JIT_H
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include <cstdlib>
Added: llvm/trunk/include/llvm/ExecutionEngine/JITMemoryManager.h
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ExecutionEngine/JITMemoryManager.h?rev=44640&view=auto
==============================================================================
--- llvm/trunk/include/llvm/ExecutionEngine/JITMemoryManager.h (added)
+++ llvm/trunk/include/llvm/ExecutionEngine/JITMemoryManager.h Wed Dec 5
17:39:57 2007
@@ -0,0 +1,96 @@
+//===-- JITMemoryManager.h - Interface JIT uses to Allocate Mem -*- C++
-*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the JITMemoryManagerInterface
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTION_ENGINE_JIT_H
+#define LLVM_EXECUTION_ENGINE_JIT_H
+
+#include "llvm/Support/DataTypes.h"
+
+namespace llvm {
+ class Function;
+
+/// JITMemoryManager - This interface is used by the JIT to allocate and manage
+/// memory for the code generated by the JIT. This can be reimplemented by
+/// clients that have a strong desire to control how the layout of JIT'd memory
+/// works.
+class JITMemoryManager {
+protected:
+ bool HasGOT;
+public:
+ JITMemoryManager() : HasGOT(false) {}
+ virtual ~JITMemoryManager();
+
+ /// CreateDefaultMemManager - This is used to create the default
+ /// JIT Memory Manager if the client does not provide one to the JIT.
+ static JITMemoryManager *CreateDefaultMemManager();
+
+
//===--------------------------------------------------------------------===//
+ // Global Offset Table Management
+
//===--------------------------------------------------------------------===//
+
+ /// AllocateGOT - If the current table requires a Global Offset Table, this
+ /// method is invoked to allocate it. This method is required to set HasGOT
+ /// to true.
+ virtual void AllocateGOT() = 0;
+
+ /// isManagingGOT - Return true if the AllocateGOT method is called.
+ ///
+ bool isManagingGOT() const {
+ return HasGOT;
+ }
+
+ /// getGOTBase - If this is managing a Global Offset Table, this method
should
+ /// return a pointer to its base.
+ virtual unsigned char *getGOTBase() const = 0;
+
+
//===--------------------------------------------------------------------===//
+ // Main Allocation Functions
+
//===--------------------------------------------------------------------===//
+
+ /// startFunctionBody - When we start JITing a function, the JIT calls this
+ /// method to allocate a block of free RWX memory, which returns a pointer to
+ /// it. The JIT doesn't know ahead of time how much space it will need to
+ /// emit the function, so it doesn't pass in the size. Instead, this method
+ /// is required to pass back a "valid size". The JIT will be careful to not
+ /// write more than the returned ActualSize bytes of memory.
+ virtual unsigned char *startFunctionBody(const Function *F,
+ uintptr_t &ActualSize) = 0;
+
+ /// allocateStub - This method is called by the JIT to allocate space for a
+ /// function stub (used to handle limited branch displacements) while it is
+ /// JIT compiling a function. For example, if foo calls bar, and if bar
+ /// either needs to be lazily compiled or is a native function that exists
too
+ /// far away from the call site to work, this method will be used to make a
+ /// thunk for it. The stub should be "close" to the current function body,
+ /// but should not be included in the 'actualsize' returned by
+ /// startFunctionBody.
+ virtual unsigned char *allocateStub(unsigned StubSize, unsigned Alignment)
=0;
+
+
+ /// endFunctionBody - This method is called when the JIT is done codegen'ing
+ /// the specified function. At this point we know the size of the JIT
+ /// compiled function. This passes in FunctionStart (which was returned by
+ /// the startFunctionBody method) and FunctionEnd which is a pointer to the
+ /// actual end of the function. This method should mark the space allocated
+ /// and remember where it is in case the client wants to deallocate it.
+ virtual void endFunctionBody(const Function *F, unsigned char *FunctionStart,
+ unsigned char *FunctionEnd) = 0;
+
+ /// deallocateMemForFunction - Free JIT memory for the specified function.
+ /// This is never called when the JIT is currently emitting a function.
+ virtual void deallocateMemForFunction(const Function *F) = 0;
+};
+
+} // end namespace llvm.
+
+#endif
Modified: llvm/trunk/lib/ExecutionEngine/JIT/JITEmitter.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ExecutionEngine/JIT/JITEmitter.cpp?rev=44640&r1=44639&r2=44640&view=diff
==============================================================================
--- llvm/trunk/lib/ExecutionEngine/JIT/JITEmitter.cpp (original)
+++ llvm/trunk/lib/ExecutionEngine/JIT/JITEmitter.cpp Wed Dec 5 17:39:57 2007
@@ -22,7 +22,7 @@
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineRelocation.h"
-#include "llvm/ExecutionEngine/GenericValue.h"
+#include "llvm/ExecutionEngine/JITMemoryManager.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetJITInfo.h"
#include "llvm/Target/TargetMachine.h"
@@ -30,7 +30,6 @@
#include "llvm/Support/MutexGuard.h"
#include "llvm/System/Disassembler.h"
#include "llvm/ADT/Statistic.h"
-#include "llvm/System/Memory.h"
#include <algorithm>
using namespace llvm;
@@ -38,395 +37,6 @@
STATISTIC(NumRelos, "Number of relocations applied");
static JIT *TheJIT = 0;
-//===----------------------------------------------------------------------===//
-// JITMemoryManager code.
-//
-namespace {
- /// MemoryRangeHeader - For a range of memory, this is the header that we put
- /// on the block of memory. It is carefully crafted to be one word of
memory.
- /// Allocated blocks have just this header, free'd blocks have
FreeRangeHeader
- /// which starts with this.
- struct FreeRangeHeader;
- struct MemoryRangeHeader {
- /// ThisAllocated - This is true if this block is currently allocated. If
- /// not, this can be converted to a FreeRangeHeader.
- unsigned ThisAllocated : 1;
-
- /// PrevAllocated - Keep track of whether the block immediately before us
is
- /// allocated. If not, the word immediately before this header is the size
- /// of the previous block.
- unsigned PrevAllocated : 1;
-
- /// BlockSize - This is the size in bytes of this memory block,
- /// including this header.
- uintptr_t BlockSize : (sizeof(intptr_t)*8 - 2);
-
-
- /// getBlockAfter - Return the memory block immediately after this one.
- ///
- MemoryRangeHeader &getBlockAfter() const {
- return *(MemoryRangeHeader*)((char*)this+BlockSize);
- }
-
- /// getFreeBlockBefore - If the block before this one is free, return it,
- /// otherwise return null.
- FreeRangeHeader *getFreeBlockBefore() const {
- if (PrevAllocated) return 0;
- intptr_t PrevSize = ((intptr_t *)this)[-1];
- return (FreeRangeHeader*)((char*)this-PrevSize);
- }
-
- /// FreeBlock - Turn an allocated block into a free block, adjusting
- /// bits in the object headers, and adding an end of region memory block.
- FreeRangeHeader *FreeBlock(FreeRangeHeader *FreeList);
-
- /// TrimAllocationToSize - If this allocated block is significantly larger
- /// than NewSize, split it into two pieces (where the former is NewSize
- /// bytes, including the header), and add the new block to the free list.
- FreeRangeHeader *TrimAllocationToSize(FreeRangeHeader *FreeList,
- uint64_t NewSize);
- };
-
- /// FreeRangeHeader - For a memory block that isn't already allocated, this
- /// keeps track of the current block and has a pointer to the next free
block.
- /// Free blocks are kept on a circularly linked list.
- struct FreeRangeHeader : public MemoryRangeHeader {
- FreeRangeHeader *Prev;
- FreeRangeHeader *Next;
-
- /// getMinBlockSize - Get the minimum size for a memory block. Blocks
- /// smaller than this size cannot be created.
- static unsigned getMinBlockSize() {
- return sizeof(FreeRangeHeader)+sizeof(intptr_t);
- }
-
- /// SetEndOfBlockSizeMarker - The word at the end of every free block is
- /// known to be the size of the free block. Set it for this block.
- void SetEndOfBlockSizeMarker() {
- void *EndOfBlock = (char*)this + BlockSize;
- ((intptr_t *)EndOfBlock)[-1] = BlockSize;
- }
-
- FreeRangeHeader *RemoveFromFreeList() {
- assert(Next->Prev == this && Prev->Next == this && "Freelist broken!");
- Next->Prev = Prev;
- return Prev->Next = Next;
- }
-
- void AddToFreeList(FreeRangeHeader *FreeList) {
- Next = FreeList;
- Prev = FreeList->Prev;
- Prev->Next = this;
- Next->Prev = this;
- }
-
- /// GrowBlock - The block after this block just got deallocated. Merge it
- /// into the current block.
- void GrowBlock(uintptr_t NewSize);
-
- /// AllocateBlock - Mark this entire block allocated, updating freelists
- /// etc. This returns a pointer to the circular free-list.
- FreeRangeHeader *AllocateBlock();
- };
-}
-
-
-/// AllocateBlock - Mark this entire block allocated, updating freelists
-/// etc. This returns a pointer to the circular free-list.
-FreeRangeHeader *FreeRangeHeader::AllocateBlock() {
- assert(!ThisAllocated && !getBlockAfter().PrevAllocated &&
- "Cannot allocate an allocated block!");
- // Mark this block allocated.
- ThisAllocated = 1;
- getBlockAfter().PrevAllocated = 1;
-
- // Remove it from the free list.
- return RemoveFromFreeList();
-}
-
-/// FreeBlock - Turn an allocated block into a free block, adjusting
-/// bits in the object headers, and adding an end of region memory block.
-/// If possible, coalesce this block with neighboring blocks. Return the
-/// FreeRangeHeader to allocate from.
-FreeRangeHeader *MemoryRangeHeader::FreeBlock(FreeRangeHeader *FreeList) {
- MemoryRangeHeader *FollowingBlock = &getBlockAfter();
- assert(ThisAllocated && "This block is already allocated!");
- assert(FollowingBlock->PrevAllocated && "Flags out of sync!");
-
- FreeRangeHeader *FreeListToReturn = FreeList;
-
- // If the block after this one is free, merge it into this block.
- if (!FollowingBlock->ThisAllocated) {
- FreeRangeHeader &FollowingFreeBlock = *(FreeRangeHeader *)FollowingBlock;
- // "FreeList" always needs to be a valid free block. If we're about to
- // coalesce with it, update our notion of what the free list is.
- if (&FollowingFreeBlock == FreeList) {
- FreeList = FollowingFreeBlock.Next;
- FreeListToReturn = 0;
- assert(&FollowingFreeBlock != FreeList && "No tombstone block?");
- }
- FollowingFreeBlock.RemoveFromFreeList();
-
- // Include the following block into this one.
- BlockSize += FollowingFreeBlock.BlockSize;
- FollowingBlock = &FollowingFreeBlock.getBlockAfter();
-
- // Tell the block after the block we are coalescing that this block is
- // allocated.
- FollowingBlock->PrevAllocated = 1;
- }
-
- assert(FollowingBlock->ThisAllocated && "Missed coalescing?");
-
- if (FreeRangeHeader *PrevFreeBlock = getFreeBlockBefore()) {
- PrevFreeBlock->GrowBlock(PrevFreeBlock->BlockSize + BlockSize);
- return FreeListToReturn ? FreeListToReturn : PrevFreeBlock;
- }
-
- // Otherwise, mark this block free.
- FreeRangeHeader &FreeBlock = *(FreeRangeHeader*)this;
- FollowingBlock->PrevAllocated = 0;
- FreeBlock.ThisAllocated = 0;
-
- // Link this into the linked list of free blocks.
- FreeBlock.AddToFreeList(FreeList);
-
- // Add a marker at the end of the block, indicating the size of this free
- // block.
- FreeBlock.SetEndOfBlockSizeMarker();
- return FreeListToReturn ? FreeListToReturn : &FreeBlock;
-}
-
-/// GrowBlock - The block after this block just got deallocated. Merge it
-/// into the current block.
-void FreeRangeHeader::GrowBlock(uintptr_t NewSize) {
- assert(NewSize > BlockSize && "Not growing block?");
- BlockSize = NewSize;
- SetEndOfBlockSizeMarker();
- getBlockAfter().PrevAllocated = 0;
-}
-
-/// TrimAllocationToSize - If this allocated block is significantly larger
-/// than NewSize, split it into two pieces (where the former is NewSize
-/// bytes, including the header), and add the new block to the free list.
-FreeRangeHeader *MemoryRangeHeader::
-TrimAllocationToSize(FreeRangeHeader *FreeList, uint64_t NewSize) {
- assert(ThisAllocated && getBlockAfter().PrevAllocated &&
- "Cannot deallocate part of an allocated block!");
-
- // Round up size for alignment of header.
- unsigned HeaderAlign = __alignof(FreeRangeHeader);
- NewSize = (NewSize+ (HeaderAlign-1)) & ~(HeaderAlign-1);
-
- // Size is now the size of the block we will remove from the start of the
- // current block.
- assert(NewSize <= BlockSize &&
- "Allocating more space from this block than exists!");
-
- // If splitting this block will cause the remainder to be too small, do not
- // split the block.
- if (BlockSize <= NewSize+FreeRangeHeader::getMinBlockSize())
- return FreeList;
-
- // Otherwise, we splice the required number of bytes out of this block, form
- // a new block immediately after it, then mark this block allocated.
- MemoryRangeHeader &FormerNextBlock = getBlockAfter();
-
- // Change the size of this block.
- BlockSize = NewSize;
-
- // Get the new block we just sliced out and turn it into a free block.
- FreeRangeHeader &NewNextBlock = (FreeRangeHeader &)getBlockAfter();
- NewNextBlock.BlockSize = (char*)&FormerNextBlock - (char*)&NewNextBlock;
- NewNextBlock.ThisAllocated = 0;
- NewNextBlock.PrevAllocated = 1;
- NewNextBlock.SetEndOfBlockSizeMarker();
- FormerNextBlock.PrevAllocated = 0;
- NewNextBlock.AddToFreeList(FreeList);
- return &NewNextBlock;
-}
-
-
-namespace {
- /// JITMemoryManager - Manage memory for the JIT code generation in a
logical,
- /// sane way. This splits a large block of MAP_NORESERVE'd memory into two
- /// sections, one for function stubs, one for the functions themselves. We
- /// have to do this because we may need to emit a function stub while in the
- /// middle of emitting a function, and we don't know how large the function
we
- /// are emitting is. This never bothers to release the memory, because when
- /// we are ready to destroy the JIT, the program exits.
- class JITMemoryManager {
- std::vector<sys::MemoryBlock> Blocks; // Memory blocks allocated by the JIT
- FreeRangeHeader *FreeMemoryList; // Circular list of free blocks.
-
- // When emitting code into a memory block, this is the block.
- MemoryRangeHeader *CurBlock;
-
- unsigned char *CurStubPtr, *StubBase;
- unsigned char *GOTBase; // Target Specific reserved memory
-
- // Centralize memory block allocation.
- sys::MemoryBlock getNewMemoryBlock(unsigned size);
-
- std::map<const Function*, MemoryRangeHeader*> FunctionBlocks;
- public:
- JITMemoryManager(bool useGOT);
- ~JITMemoryManager();
-
- inline unsigned char *allocateStub(unsigned StubSize, unsigned Alignment);
-
- /// startFunctionBody - When a function starts, allocate a block of free
- /// executable memory, returning a pointer to it and its actual size.
- unsigned char *startFunctionBody(uintptr_t &ActualSize) {
- CurBlock = FreeMemoryList;
-
- // Allocate the entire memory block.
- FreeMemoryList = FreeMemoryList->AllocateBlock();
- ActualSize = CurBlock->BlockSize-sizeof(MemoryRangeHeader);
- return (unsigned char *)(CurBlock+1);
- }
-
- /// endFunctionBody - The function F is now allocated, and takes the memory
- /// in the range [FunctionStart,FunctionEnd).
- void endFunctionBody(const Function *F, unsigned char *FunctionStart,
- unsigned char *FunctionEnd) {
- assert(FunctionEnd > FunctionStart);
- assert(FunctionStart == (unsigned char *)(CurBlock+1) &&
- "Mismatched function start/end!");
-
- uintptr_t BlockSize = FunctionEnd - (unsigned char *)CurBlock;
- FunctionBlocks[F] = CurBlock;
-
- // Release the memory at the end of this block that isn't needed.
- FreeMemoryList =CurBlock->TrimAllocationToSize(FreeMemoryList,
BlockSize);
- }
-
- unsigned char *getGOTBase() const {
- return GOTBase;
- }
- bool isManagingGOT() const {
- return GOTBase != NULL;
- }
-
- /// deallocateMemForFunction - Deallocate all memory for the specified
- /// function body.
- void deallocateMemForFunction(const Function *F) {
- std::map<const Function*, MemoryRangeHeader*>::iterator
- I = FunctionBlocks.find(F);
- if (I == FunctionBlocks.end()) return;
-
- // Find the block that is allocated for this function.
- MemoryRangeHeader *MemRange = I->second;
- assert(MemRange->ThisAllocated && "Block isn't allocated!");
-
- // Fill the buffer with garbage!
- DEBUG(memset(MemRange+1, 0xCD, MemRange->BlockSize-sizeof(*MemRange)));
-
- // Free the memory.
- FreeMemoryList = MemRange->FreeBlock(FreeMemoryList);
-
- // Finally, remove this entry from FunctionBlocks.
- FunctionBlocks.erase(I);
- }
- };
-}
-
-JITMemoryManager::JITMemoryManager(bool useGOT) {
- // Allocate a 16M block of memory for functions.
- sys::MemoryBlock MemBlock = getNewMemoryBlock(16 << 20);
-
- unsigned char *MemBase = reinterpret_cast<unsigned char*>(MemBlock.base());
-
- // Allocate stubs backwards from the base, allocate functions forward
- // from the base.
- StubBase = MemBase;
- CurStubPtr = MemBase + 512*1024; // Use 512k for stubs, working backwards.
-
- // We set up the memory chunk with 4 mem regions, like this:
- // [ START
- // [ Free #0 ] -> Large space to allocate functions from.
- // [ Allocated #1 ] -> Tiny space to separate regions.
- // [ Free #2 ] -> Tiny space so there is always at least 1 free
block.
- // [ Allocated #3 ] -> Tiny space to prevent looking past end of block.
- // END ]
- //
- // The last three blocks are never deallocated or touched.
-
- // Add MemoryRangeHeader to the end of the memory region, indicating that
- // the space after the block of memory is allocated. This is block #3.
- MemoryRangeHeader *Mem3 = (MemoryRangeHeader*)(MemBase+MemBlock.size())-1;
- Mem3->ThisAllocated = 1;
- Mem3->PrevAllocated = 0;
- Mem3->BlockSize = 0;
-
- /// Add a tiny free region so that the free list always has one entry.
- FreeRangeHeader *Mem2 =
- (FreeRangeHeader *)(((char*)Mem3)-FreeRangeHeader::getMinBlockSize());
- Mem2->ThisAllocated = 0;
- Mem2->PrevAllocated = 1;
- Mem2->BlockSize = FreeRangeHeader::getMinBlockSize();
- Mem2->SetEndOfBlockSizeMarker();
- Mem2->Prev = Mem2; // Mem2 *is* the free list for now.
- Mem2->Next = Mem2;
-
- /// Add a tiny allocated region so that Mem2 is never coalesced away.
- MemoryRangeHeader *Mem1 = (MemoryRangeHeader*)Mem2-1;
- Mem1->ThisAllocated = 1;
- Mem1->PrevAllocated = 0;
- Mem1->BlockSize = (char*)Mem2 - (char*)Mem1;
-
- // Add a FreeRangeHeader to the start of the function body region, indicating
- // that the space is free. Mark the previous block allocated so we never
look
- // at it.
- FreeRangeHeader *Mem0 = (FreeRangeHeader*)CurStubPtr;
- Mem0->ThisAllocated = 0;
- Mem0->PrevAllocated = 1;
- Mem0->BlockSize = (char*)Mem1-(char*)Mem0;
- Mem0->SetEndOfBlockSizeMarker();
- Mem0->AddToFreeList(Mem2);
-
- // Start out with the freelist pointing to Mem0.
- FreeMemoryList = Mem0;
-
- // Allocate the GOT.
- GOTBase = NULL;
- if (useGOT) GOTBase = new unsigned char[sizeof(void*) * 8192];
-}
-
-JITMemoryManager::~JITMemoryManager() {
- for (unsigned i = 0, e = Blocks.size(); i != e; ++i)
- sys::Memory::ReleaseRWX(Blocks[i]);
-
- delete[] GOTBase;
- Blocks.clear();
-}
-
-unsigned char *JITMemoryManager::allocateStub(unsigned StubSize,
- unsigned Alignment) {
- CurStubPtr -= StubSize;
- CurStubPtr = (unsigned char*)(((intptr_t)CurStubPtr) &
- ~(intptr_t)(Alignment-1));
- if (CurStubPtr < StubBase) {
- // FIXME: allocate a new block
- cerr << "JIT ran out of memory for function stubs!\n";
- abort();
- }
- return CurStubPtr;
-}
-
-sys::MemoryBlock JITMemoryManager::getNewMemoryBlock(unsigned size) {
- // Allocate a new block close to the last one.
- const sys::MemoryBlock *BOld = Blocks.empty() ? 0 : &Blocks.front();
- std::string ErrMsg;
- sys::MemoryBlock B = sys::Memory::AllocateRWX(size, BOld, &ErrMsg);
- if (B.base() == 0) {
- cerr << "Allocation failed when allocating new memory in the JIT\n";
- cerr << ErrMsg << "\n";
- abort();
- }
- Blocks.push_back(B);
- return B;
-}
//===----------------------------------------------------------------------===//
// JIT lazy compilation code.
@@ -504,9 +114,9 @@
}
/// getGOTIndexForAddress - Return a new or existing index in the GOT for
- /// and address. This function only manages slots, it does not manage the
+ /// an 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);
+ 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
@@ -597,7 +207,6 @@
revGOTMap[addr] = idx;
DOUT << "Adding GOT entry " << idx
<< " for addr " << addr << "\n";
- // ((void**)MemMgr.getGOTBase())[idx] = addr;
}
return idx;
}
@@ -669,7 +278,7 @@
/// JITEmitter - The JIT implementation of the MachineCodeEmitter, which is
/// used to output functions to memory for execution.
class JITEmitter : public MachineCodeEmitter {
- JITMemoryManager MemMgr;
+ JITMemoryManager *MemMgr;
// When outputting a function stub in the context of some other function,
we
// save BufferBegin/BufferEnd/CurBufferPtr here.
@@ -703,9 +312,15 @@
/// Resolver - This contains info about the currently resolved functions.
JITResolver Resolver;
public:
- JITEmitter(JIT &jit)
- : MemMgr(jit.getJITInfo().needsGOT()), Resolver(jit) {
- if (MemMgr.isManagingGOT()) DOUT << "JIT is managing a GOT\n";
+ JITEmitter(JIT &jit) : Resolver(jit) {
+ MemMgr = JITMemoryManager::CreateDefaultMemManager();
+ if (jit.getJITInfo().needsGOT()) {
+ MemMgr->AllocateGOT();
+ DOUT << "JIT is managing a GOT\n";
+ }
+ }
+ ~JITEmitter() {
+ delete MemMgr;
}
JITResolver &getJITResolver() { return Resolver; }
@@ -742,7 +357,7 @@
/// deallocateMemForFunction - Deallocate all memory for the specified
/// function body.
void deallocateMemForFunction(Function *F) {
- MemMgr.deallocateMemForFunction(F);
+ MemMgr->deallocateMemForFunction(F);
}
private:
void *getPointerToGlobal(GlobalValue *GV, void *Reference, bool
NoNeedStub);
@@ -783,7 +398,8 @@
void JITEmitter::startFunction(MachineFunction &F) {
uintptr_t ActualSize;
- BufferBegin = CurBufferPtr = MemMgr.startFunctionBody(ActualSize);
+ BufferBegin = CurBufferPtr = MemMgr->startFunctionBody(F.getFunction(),
+ ActualSize);
BufferEnd = BufferBegin+ActualSize;
// Ensure the constant pool/jump table info is at least 4-byte aligned.
@@ -814,7 +430,7 @@
(unsigned char *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
unsigned char *FnEnd = CurBufferPtr;
- MemMgr.endFunctionBody(F.getFunction(), BufferBegin, FnEnd);
+ MemMgr->endFunctionBody(F.getFunction(), BufferBegin, FnEnd);
NumBytes += FnEnd-FnStart;
if (!Relocations.empty()) {
@@ -847,29 +463,29 @@
// if we are managing the GOT and the relocation wants an index,
// give it one
- if (MemMgr.isManagingGOT() && MR.isGOTRelative()) {
+ if (MR.isGOTRelative() && MemMgr->isManagingGOT()) {
unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr);
MR.setGOTIndex(idx);
- if (((void**)MemMgr.getGOTBase())[idx] != ResultPtr) {
+ if (((void**)MemMgr->getGOTBase())[idx] != ResultPtr) {
DOUT << "GOT was out of date for " << ResultPtr
- << " pointing at " << ((void**)MemMgr.getGOTBase())[idx]
+ << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
<< "\n";
- ((void**)MemMgr.getGOTBase())[idx] = ResultPtr;
+ ((void**)MemMgr->getGOTBase())[idx] = ResultPtr;
}
}
}
TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
- Relocations.size(), MemMgr.getGOTBase());
+ Relocations.size(), MemMgr->getGOTBase());
}
// Update the GOT entry for F to point to the new code.
- if (MemMgr.isManagingGOT()) {
+ if (MemMgr->isManagingGOT()) {
unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin);
- if (((void**)MemMgr.getGOTBase())[idx] != (void*)BufferBegin) {
+ if (((void**)MemMgr->getGOTBase())[idx] != (void*)BufferBegin) {
DOUT << "GOT was out of date for " << (void*)BufferBegin
- << " pointing at " << ((void**)MemMgr.getGOTBase())[idx] << "\n";
- ((void**)MemMgr.getGOTBase())[idx] = (void*)BufferBegin;
+ << " pointing at " << ((void**)MemMgr->getGOTBase())[idx] << "\n";
+ ((void**)MemMgr->getGOTBase())[idx] = (void*)BufferBegin;
}
}
@@ -976,7 +592,7 @@
SavedBufferEnd = BufferEnd;
SavedCurBufferPtr = CurBufferPtr;
- BufferBegin = CurBufferPtr = MemMgr.allocateStub(StubSize, Alignment);
+ BufferBegin = CurBufferPtr = MemMgr->allocateStub(StubSize, Alignment);
BufferEnd = BufferBegin+StubSize+1;
}
Added: llvm/trunk/lib/ExecutionEngine/JIT/JITMemoryManager.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ExecutionEngine/JIT/JITMemoryManager.cpp?rev=44640&view=auto
==============================================================================
--- llvm/trunk/lib/ExecutionEngine/JIT/JITMemoryManager.cpp (added)
+++ llvm/trunk/lib/ExecutionEngine/JIT/JITMemoryManager.cpp Wed Dec 5 17:39:57
2007
@@ -0,0 +1,427 @@
+//===-- JITMemoryManager.cpp - Memory Allocator for JIT'd code
------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the DefaultJITMemoryManager class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ExecutionEngine/JITMemoryManager.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/System/Memory.h"
+#include <map>
+#include <vector>
+using namespace llvm;
+
+
+JITMemoryManager::~JITMemoryManager() {}
+
+//===----------------------------------------------------------------------===//
+// Memory Block Implementation.
+//===----------------------------------------------------------------------===//
+
+namespace {
+ /// MemoryRangeHeader - For a range of memory, this is the header that we put
+ /// on the block of memory. It is carefully crafted to be one word of
memory.
+ /// Allocated blocks have just this header, free'd blocks have
FreeRangeHeader
+ /// which starts with this.
+ struct FreeRangeHeader;
+ struct MemoryRangeHeader {
+ /// ThisAllocated - This is true if this block is currently allocated. If
+ /// not, this can be converted to a FreeRangeHeader.
+ unsigned ThisAllocated : 1;
+
+ /// PrevAllocated - Keep track of whether the block immediately before us
is
+ /// allocated. If not, the word immediately before this header is the size
+ /// of the previous block.
+ unsigned PrevAllocated : 1;
+
+ /// BlockSize - This is the size in bytes of this memory block,
+ /// including this header.
+ uintptr_t BlockSize : (sizeof(intptr_t)*8 - 2);
+
+
+ /// getBlockAfter - Return the memory block immediately after this one.
+ ///
+ MemoryRangeHeader &getBlockAfter() const {
+ return *(MemoryRangeHeader*)((char*)this+BlockSize);
+ }
+
+ /// getFreeBlockBefore - If the block before this one is free, return it,
+ /// otherwise return null.
+ FreeRangeHeader *getFreeBlockBefore() const {
+ if (PrevAllocated) return 0;
+ intptr_t PrevSize = ((intptr_t *)this)[-1];
+ return (FreeRangeHeader*)((char*)this-PrevSize);
+ }
+
+ /// FreeBlock - Turn an allocated block into a free block, adjusting
+ /// bits in the object headers, and adding an end of region memory block.
+ FreeRangeHeader *FreeBlock(FreeRangeHeader *FreeList);
+
+ /// TrimAllocationToSize - If this allocated block is significantly larger
+ /// than NewSize, split it into two pieces (where the former is NewSize
+ /// bytes, including the header), and add the new block to the free list.
+ FreeRangeHeader *TrimAllocationToSize(FreeRangeHeader *FreeList,
+ uint64_t NewSize);
+ };
+
+ /// FreeRangeHeader - For a memory block that isn't already allocated, this
+ /// keeps track of the current block and has a pointer to the next free
block.
+ /// Free blocks are kept on a circularly linked list.
+ struct FreeRangeHeader : public MemoryRangeHeader {
+ FreeRangeHeader *Prev;
+ FreeRangeHeader *Next;
+
+ /// getMinBlockSize - Get the minimum size for a memory block. Blocks
+ /// smaller than this size cannot be created.
+ static unsigned getMinBlockSize() {
+ return sizeof(FreeRangeHeader)+sizeof(intptr_t);
+ }
+
+ /// SetEndOfBlockSizeMarker - The word at the end of every free block is
+ /// known to be the size of the free block. Set it for this block.
+ void SetEndOfBlockSizeMarker() {
+ void *EndOfBlock = (char*)this + BlockSize;
+ ((intptr_t *)EndOfBlock)[-1] = BlockSize;
+ }
+
+ FreeRangeHeader *RemoveFromFreeList() {
+ assert(Next->Prev == this && Prev->Next == this && "Freelist broken!");
+ Next->Prev = Prev;
+ return Prev->Next = Next;
+ }
+
+ void AddToFreeList(FreeRangeHeader *FreeList) {
+ Next = FreeList;
+ Prev = FreeList->Prev;
+ Prev->Next = this;
+ Next->Prev = this;
+ }
+
+ /// GrowBlock - The block after this block just got deallocated. Merge it
+ /// into the current block.
+ void GrowBlock(uintptr_t NewSize);
+
+ /// AllocateBlock - Mark this entire block allocated, updating freelists
+ /// etc. This returns a pointer to the circular free-list.
+ FreeRangeHeader *AllocateBlock();
+ };
+}
+
+
+/// AllocateBlock - Mark this entire block allocated, updating freelists
+/// etc. This returns a pointer to the circular free-list.
+FreeRangeHeader *FreeRangeHeader::AllocateBlock() {
+ assert(!ThisAllocated && !getBlockAfter().PrevAllocated &&
+ "Cannot allocate an allocated block!");
+ // Mark this block allocated.
+ ThisAllocated = 1;
+ getBlockAfter().PrevAllocated = 1;
+
+ // Remove it from the free list.
+ return RemoveFromFreeList();
+}
+
+/// FreeBlock - Turn an allocated block into a free block, adjusting
+/// bits in the object headers, and adding an end of region memory block.
+/// If possible, coalesce this block with neighboring blocks. Return the
+/// FreeRangeHeader to allocate from.
+FreeRangeHeader *MemoryRangeHeader::FreeBlock(FreeRangeHeader *FreeList) {
+ MemoryRangeHeader *FollowingBlock = &getBlockAfter();
+ assert(ThisAllocated && "This block is already allocated!");
+ assert(FollowingBlock->PrevAllocated && "Flags out of sync!");
+
+ FreeRangeHeader *FreeListToReturn = FreeList;
+
+ // If the block after this one is free, merge it into this block.
+ if (!FollowingBlock->ThisAllocated) {
+ FreeRangeHeader &FollowingFreeBlock = *(FreeRangeHeader *)FollowingBlock;
+ // "FreeList" always needs to be a valid free block. If we're about to
+ // coalesce with it, update our notion of what the free list is.
+ if (&FollowingFreeBlock == FreeList) {
+ FreeList = FollowingFreeBlock.Next;
+ FreeListToReturn = 0;
+ assert(&FollowingFreeBlock != FreeList && "No tombstone block?");
+ }
+ FollowingFreeBlock.RemoveFromFreeList();
+
+ // Include the following block into this one.
+ BlockSize += FollowingFreeBlock.BlockSize;
+ FollowingBlock = &FollowingFreeBlock.getBlockAfter();
+
+ // Tell the block after the block we are coalescing that this block is
+ // allocated.
+ FollowingBlock->PrevAllocated = 1;
+ }
+
+ assert(FollowingBlock->ThisAllocated && "Missed coalescing?");
+
+ if (FreeRangeHeader *PrevFreeBlock = getFreeBlockBefore()) {
+ PrevFreeBlock->GrowBlock(PrevFreeBlock->BlockSize + BlockSize);
+ return FreeListToReturn ? FreeListToReturn : PrevFreeBlock;
+ }
+
+ // Otherwise, mark this block free.
+ FreeRangeHeader &FreeBlock = *(FreeRangeHeader*)this;
+ FollowingBlock->PrevAllocated = 0;
+ FreeBlock.ThisAllocated = 0;
+
+ // Link this into the linked list of free blocks.
+ FreeBlock.AddToFreeList(FreeList);
+
+ // Add a marker at the end of the block, indicating the size of this free
+ // block.
+ FreeBlock.SetEndOfBlockSizeMarker();
+ return FreeListToReturn ? FreeListToReturn : &FreeBlock;
+}
+
+/// GrowBlock - The block after this block just got deallocated. Merge it
+/// into the current block.
+void FreeRangeHeader::GrowBlock(uintptr_t NewSize) {
+ assert(NewSize > BlockSize && "Not growing block?");
+ BlockSize = NewSize;
+ SetEndOfBlockSizeMarker();
+ getBlockAfter().PrevAllocated = 0;
+}
+
+/// TrimAllocationToSize - If this allocated block is significantly larger
+/// than NewSize, split it into two pieces (where the former is NewSize
+/// bytes, including the header), and add the new block to the free list.
+FreeRangeHeader *MemoryRangeHeader::
+TrimAllocationToSize(FreeRangeHeader *FreeList, uint64_t NewSize) {
+ assert(ThisAllocated && getBlockAfter().PrevAllocated &&
+ "Cannot deallocate part of an allocated block!");
+
+ // Round up size for alignment of header.
+ unsigned HeaderAlign = __alignof(FreeRangeHeader);
+ NewSize = (NewSize+ (HeaderAlign-1)) & ~(HeaderAlign-1);
+
+ // Size is now the size of the block we will remove from the start of the
+ // current block.
+ assert(NewSize <= BlockSize &&
+ "Allocating more space from this block than exists!");
+
+ // If splitting this block will cause the remainder to be too small, do not
+ // split the block.
+ if (BlockSize <= NewSize+FreeRangeHeader::getMinBlockSize())
+ return FreeList;
+
+ // Otherwise, we splice the required number of bytes out of this block, form
+ // a new block immediately after it, then mark this block allocated.
+ MemoryRangeHeader &FormerNextBlock = getBlockAfter();
+
+ // Change the size of this block.
+ BlockSize = NewSize;
+
+ // Get the new block we just sliced out and turn it into a free block.
+ FreeRangeHeader &NewNextBlock = (FreeRangeHeader &)getBlockAfter();
+ NewNextBlock.BlockSize = (char*)&FormerNextBlock - (char*)&NewNextBlock;
+ NewNextBlock.ThisAllocated = 0;
+ NewNextBlock.PrevAllocated = 1;
+ NewNextBlock.SetEndOfBlockSizeMarker();
+ FormerNextBlock.PrevAllocated = 0;
+ NewNextBlock.AddToFreeList(FreeList);
+ return &NewNextBlock;
+}
+
+//===----------------------------------------------------------------------===//
+// Memory Block Implementation.
+//===----------------------------------------------------------------------===//
+
+namespace {
+ /// DefaultJITMemoryManager - Manage memory for the JIT code generation.
+ /// This splits a large block of MAP_NORESERVE'd memory into two
+ /// sections, one for function stubs, one for the functions themselves. We
+ /// have to do this because we may need to emit a function stub while in the
+ /// middle of emitting a function, and we don't know how large the function
we
+ /// are emitting is.
+ class VISIBILITY_HIDDEN DefaultJITMemoryManager : public JITMemoryManager {
+ std::vector<sys::MemoryBlock> Blocks; // Memory blocks allocated by the JIT
+ FreeRangeHeader *FreeMemoryList; // Circular list of free blocks.
+
+ // When emitting code into a memory block, this is the block.
+ MemoryRangeHeader *CurBlock;
+
+ unsigned char *CurStubPtr, *StubBase;
+ unsigned char *GOTBase; // Target Specific reserved memory
+
+ // Centralize memory block allocation.
+ sys::MemoryBlock getNewMemoryBlock(unsigned size);
+
+ std::map<const Function*, MemoryRangeHeader*> FunctionBlocks;
+ public:
+ DefaultJITMemoryManager();
+ ~DefaultJITMemoryManager();
+
+ void AllocateGOT();
+
+ unsigned char *allocateStub(unsigned StubSize, unsigned Alignment);
+
+ /// startFunctionBody - When a function starts, allocate a block of free
+ /// executable memory, returning a pointer to it and its actual size.
+ unsigned char *startFunctionBody(const Function *F, uintptr_t &ActualSize)
{
+ CurBlock = FreeMemoryList;
+
+ // Allocate the entire memory block.
+ FreeMemoryList = FreeMemoryList->AllocateBlock();
+ ActualSize = CurBlock->BlockSize-sizeof(MemoryRangeHeader);
+ return (unsigned char *)(CurBlock+1);
+ }
+
+ /// endFunctionBody - The function F is now allocated, and takes the memory
+ /// in the range [FunctionStart,FunctionEnd).
+ void endFunctionBody(const Function *F, unsigned char *FunctionStart,
+ unsigned char *FunctionEnd) {
+ assert(FunctionEnd > FunctionStart);
+ assert(FunctionStart == (unsigned char *)(CurBlock+1) &&
+ "Mismatched function start/end!");
+
+ uintptr_t BlockSize = FunctionEnd - (unsigned char *)CurBlock;
+ FunctionBlocks[F] = CurBlock;
+
+ // Release the memory at the end of this block that isn't needed.
+ FreeMemoryList =CurBlock->TrimAllocationToSize(FreeMemoryList,
BlockSize);
+ }
+
+ unsigned char *getGOTBase() const {
+ return GOTBase;
+ }
+
+ /// deallocateMemForFunction - Deallocate all memory for the specified
+ /// function body.
+ void deallocateMemForFunction(const Function *F) {
+ std::map<const Function*, MemoryRangeHeader*>::iterator
+ I = FunctionBlocks.find(F);
+ if (I == FunctionBlocks.end()) return;
+
+ // Find the block that is allocated for this function.
+ MemoryRangeHeader *MemRange = I->second;
+ assert(MemRange->ThisAllocated && "Block isn't allocated!");
+
+ // Fill the buffer with garbage!
+#ifndef NDEBUG
+ memset(MemRange+1, 0xCD, MemRange->BlockSize-sizeof(*MemRange));
+#endif
+
+ // Free the memory.
+ FreeMemoryList = MemRange->FreeBlock(FreeMemoryList);
+
+ // Finally, remove this entry from FunctionBlocks.
+ FunctionBlocks.erase(I);
+ }
+ };
+}
+
+DefaultJITMemoryManager::DefaultJITMemoryManager() {
+ // Allocate a 16M block of memory for functions.
+ sys::MemoryBlock MemBlock = getNewMemoryBlock(16 << 20);
+
+ unsigned char *MemBase = reinterpret_cast<unsigned char*>(MemBlock.base());
+
+ // Allocate stubs backwards from the base, allocate functions forward
+ // from the base.
+ StubBase = MemBase;
+ CurStubPtr = MemBase + 512*1024; // Use 512k for stubs, working backwards.
+
+ // We set up the memory chunk with 4 mem regions, like this:
+ // [ START
+ // [ Free #0 ] -> Large space to allocate functions from.
+ // [ Allocated #1 ] -> Tiny space to separate regions.
+ // [ Free #2 ] -> Tiny space so there is always at least 1 free
block.
+ // [ Allocated #3 ] -> Tiny space to prevent looking past end of block.
+ // END ]
+ //
+ // The last three blocks are never deallocated or touched.
+
+ // Add MemoryRangeHeader to the end of the memory region, indicating that
+ // the space after the block of memory is allocated. This is block #3.
+ MemoryRangeHeader *Mem3 = (MemoryRangeHeader*)(MemBase+MemBlock.size())-1;
+ Mem3->ThisAllocated = 1;
+ Mem3->PrevAllocated = 0;
+ Mem3->BlockSize = 0;
+
+ /// Add a tiny free region so that the free list always has one entry.
+ FreeRangeHeader *Mem2 =
+ (FreeRangeHeader *)(((char*)Mem3)-FreeRangeHeader::getMinBlockSize());
+ Mem2->ThisAllocated = 0;
+ Mem2->PrevAllocated = 1;
+ Mem2->BlockSize = FreeRangeHeader::getMinBlockSize();
+ Mem2->SetEndOfBlockSizeMarker();
+ Mem2->Prev = Mem2; // Mem2 *is* the free list for now.
+ Mem2->Next = Mem2;
+
+ /// Add a tiny allocated region so that Mem2 is never coalesced away.
+ MemoryRangeHeader *Mem1 = (MemoryRangeHeader*)Mem2-1;
+ Mem1->ThisAllocated = 1;
+ Mem1->PrevAllocated = 0;
+ Mem1->BlockSize = (char*)Mem2 - (char*)Mem1;
+
+ // Add a FreeRangeHeader to the start of the function body region, indicating
+ // that the space is free. Mark the previous block allocated so we never
look
+ // at it.
+ FreeRangeHeader *Mem0 = (FreeRangeHeader*)CurStubPtr;
+ Mem0->ThisAllocated = 0;
+ Mem0->PrevAllocated = 1;
+ Mem0->BlockSize = (char*)Mem1-(char*)Mem0;
+ Mem0->SetEndOfBlockSizeMarker();
+ Mem0->AddToFreeList(Mem2);
+
+ // Start out with the freelist pointing to Mem0.
+ FreeMemoryList = Mem0;
+
+ GOTBase = NULL;
+}
+
+void DefaultJITMemoryManager::AllocateGOT() {
+ assert(GOTBase == 0 && "Cannot allocate the got multiple times");
+ GOTBase = new unsigned char[sizeof(void*) * 8192];
+ HasGOT = true;
+}
+
+
+DefaultJITMemoryManager::~DefaultJITMemoryManager() {
+ for (unsigned i = 0, e = Blocks.size(); i != e; ++i)
+ sys::Memory::ReleaseRWX(Blocks[i]);
+
+ delete[] GOTBase;
+ Blocks.clear();
+}
+
+unsigned char *DefaultJITMemoryManager::allocateStub(unsigned StubSize,
+ unsigned Alignment) {
+ CurStubPtr -= StubSize;
+ CurStubPtr = (unsigned char*)(((intptr_t)CurStubPtr) &
+ ~(intptr_t)(Alignment-1));
+ if (CurStubPtr < StubBase) {
+ // FIXME: allocate a new block
+ fprintf(stderr, "JIT ran out of memory for function stubs!\n");
+ abort();
+ }
+ return CurStubPtr;
+}
+
+sys::MemoryBlock DefaultJITMemoryManager::getNewMemoryBlock(unsigned size) {
+ // Allocate a new block close to the last one.
+ const sys::MemoryBlock *BOld = Blocks.empty() ? 0 : &Blocks.front();
+ std::string ErrMsg;
+ sys::MemoryBlock B = sys::Memory::AllocateRWX(size, BOld, &ErrMsg);
+ if (B.base() == 0) {
+ fprintf(stderr,
+ "Allocation failed when allocating new memory in the JIT\n%s\n",
+ ErrMsg.c_str());
+ abort();
+ }
+ Blocks.push_back(B);
+ return B;
+}
+
+
+JITMemoryManager *JITMemoryManager::CreateDefaultMemManager() {
+ return new DefaultJITMemoryManager();
+}
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