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- Code clean up to reduce indentation.

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- TryToOptimizeStoreOfMallocToGlobal should check if TargetData is available and bail out if it is not. The transformations being done requires TD.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101285 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2010-04-14 20:52:55 +00:00
parent 7b975f411f
commit 86cd445645
1 changed files with 55 additions and 52 deletions
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107
lib/Transforms/IPO/GlobalOpt.cpp
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@ -1462,6 +1462,9 @@ static bool TryToOptimizeStoreOfMallocToGlobal(GlobalVariable *GV,
const Type *AllocTy,
Module::global_iterator &GVI,
TargetData *TD) {
if (!TD)
return false;
// If this is a malloc of an abstract type, don't touch it.
if (!AllocTy->isSized())
return false;
@ -1480,66 +1483,66 @@ static bool TryToOptimizeStoreOfMallocToGlobal(GlobalVariable *GV,
// malloc to be stored into the specified global, loaded setcc'd, and
// GEP'd. These are all things we could transform to using the global
// for.
{
SmallPtrSet<const PHINode*, 8> PHIs;
if (!ValueIsOnlyUsedLocallyOrStoredToOneGlobal(CI, GV, PHIs))
return false;
}
SmallPtrSet<const PHINode*, 8> PHIs;
if (!ValueIsOnlyUsedLocallyOrStoredToOneGlobal(CI, GV, PHIs))
return false;
// If we have a global that is only initialized with a fixed size malloc,
// transform the program to use global memory instead of malloc'd memory.
// This eliminates dynamic allocation, avoids an indirection accessing the
// data, and exposes the resultant global to further GlobalOpt.
// We cannot optimize the malloc if we cannot determine malloc array size.
if (Value *NElems = getMallocArraySize(CI, TD, true)) {
if (ConstantInt *NElements = dyn_cast<ConstantInt>(NElems))
// Restrict this transformation to only working on small allocations
// (2048 bytes currently), as we don't want to introduce a 16M global or
// something.
if (TD &&
NElements->getZExtValue() * TD->getTypeAllocSize(AllocTy) < 2048) {
GVI = OptimizeGlobalAddressOfMalloc(GV, CI, AllocTy, NElements, TD);
return true;
}
// If the allocation is an array of structures, consider transforming this
// into multiple malloc'd arrays, one for each field. This is basically
// SRoA for malloc'd memory.
Value *NElems = getMallocArraySize(CI, TD, true);
if (!NElems)
return false;
// If this is an allocation of a fixed size array of structs, analyze as a
// variable size array. malloc [100 x struct],1 -> malloc struct, 100
if (NElems == ConstantInt::get(CI->getOperand(1)->getType(), 1))
if (const ArrayType *AT = dyn_cast<ArrayType>(AllocTy))
AllocTy = AT->getElementType();
if (const StructType *AllocSTy = dyn_cast<StructType>(AllocTy)) {
// This the structure has an unreasonable number of fields, leave it
// alone.
if (AllocSTy->getNumElements() <= 16 && AllocSTy->getNumElements() != 0 &&
AllGlobalLoadUsesSimpleEnoughForHeapSRA(GV, CI)) {
// If this is a fixed size array, transform the Malloc to be an alloc of
// structs. malloc [100 x struct],1 -> malloc struct, 100
if (const ArrayType *AT =
dyn_cast<ArrayType>(getMallocAllocatedType(CI))) {
const Type *IntPtrTy = TD->getIntPtrType(CI->getContext());
unsigned TypeSize = TD->getStructLayout(AllocSTy)->getSizeInBytes();
Value *AllocSize = ConstantInt::get(IntPtrTy, TypeSize);
Value *NumElements = ConstantInt::get(IntPtrTy, AT->getNumElements());
Instruction *Malloc = CallInst::CreateMalloc(CI, IntPtrTy, AllocSTy,
AllocSize, NumElements,
CI->getName());
Instruction *Cast = new BitCastInst(Malloc, CI->getType(), "tmp", CI);
CI->replaceAllUsesWith(Cast);
CI->eraseFromParent();
CI = dyn_cast<BitCastInst>(Malloc) ?
extractMallocCallFromBitCast(Malloc) : cast<CallInst>(Malloc);
}
GVI = PerformHeapAllocSRoA(GV, CI, getMallocArraySize(CI, TD, true),TD);
return true;
}
if (ConstantInt *NElements = dyn_cast<ConstantInt>(NElems))
// Restrict this transformation to only working on small allocations
// (2048 bytes currently), as we don't want to introduce a 16M global or
// something.
if (NElements->getZExtValue() * TD->getTypeAllocSize(AllocTy) < 2048) {
GVI = OptimizeGlobalAddressOfMalloc(GV, CI, AllocTy, NElements, TD);
return true;
}
// If the allocation is an array of structures, consider transforming this
// into multiple malloc'd arrays, one for each field. This is basically
// SRoA for malloc'd memory.
// If this is an allocation of a fixed size array of structs, analyze as a
// variable size array. malloc [100 x struct],1 -> malloc struct, 100
if (NElems == ConstantInt::get(CI->getOperand(1)->getType(), 1))
if (const ArrayType *AT = dyn_cast<ArrayType>(AllocTy))
AllocTy = AT->getElementType();
const StructType *AllocSTy = dyn_cast<StructType>(AllocTy);
if (!AllocSTy)
return false;
// This the structure has an unreasonable number of fields, leave it
// alone.
if (AllocSTy->getNumElements() <= 16 && AllocSTy->getNumElements() != 0 &&
AllGlobalLoadUsesSimpleEnoughForHeapSRA(GV, CI)) {
// If this is a fixed size array, transform the Malloc to be an alloc of
// structs. malloc [100 x struct],1 -> malloc struct, 100
if (const ArrayType *AT = dyn_cast<ArrayType>(getMallocAllocatedType(CI))) {
const Type *IntPtrTy = TD->getIntPtrType(CI->getContext());
unsigned TypeSize = TD->getStructLayout(AllocSTy)->getSizeInBytes();
Value *AllocSize = ConstantInt::get(IntPtrTy, TypeSize);
Value *NumElements = ConstantInt::get(IntPtrTy, AT->getNumElements());
Instruction *Malloc = CallInst::CreateMalloc(CI, IntPtrTy, AllocSTy,
AllocSize, NumElements,
CI->getName());
Instruction *Cast = new BitCastInst(Malloc, CI->getType(), "tmp", CI);
CI->replaceAllUsesWith(Cast);
CI->eraseFromParent();
CI = dyn_cast<BitCastInst>(Malloc) ?
extractMallocCallFromBitCast(Malloc) : cast<CallInst>(Malloc);
}
GVI = PerformHeapAllocSRoA(GV, CI, getMallocArraySize(CI, TD, true),TD);
return true;
}
return false;