change GetStoreValueForLoad to use IRBuilder, which is cleaner and

implicitly constant folds.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90977 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2009-12-09 18:13:28 +00:00
parent efc58e7933
commit b2c6ae8c0b

View File

@ -1151,14 +1151,15 @@ static Value *GetStoreValueForLoad(Value *SrcVal, unsigned Offset,
uint64_t StoreSize = TD.getTypeSizeInBits(SrcVal->getType())/8;
uint64_t LoadSize = TD.getTypeSizeInBits(LoadTy)/8;
IRBuilder<> Builder(InsertPt->getParent(), InsertPt);
// Compute which bits of the stored value are being used by the load. Convert
// to an integer type to start with.
if (isa<PointerType>(SrcVal->getType()))
SrcVal = new PtrToIntInst(SrcVal, TD.getIntPtrType(Ctx), "tmp", InsertPt);
SrcVal = Builder.CreatePtrToInt(SrcVal, TD.getIntPtrType(Ctx), "tmp");
if (!isa<IntegerType>(SrcVal->getType()))
SrcVal = new BitCastInst(SrcVal, IntegerType::get(Ctx, StoreSize*8),
"tmp", InsertPt);
SrcVal = Builder.CreateBitCast(SrcVal, IntegerType::get(Ctx, StoreSize*8),
"tmp");
// Shift the bits to the least significant depending on endianness.
unsigned ShiftAmt;
@ -1168,12 +1169,11 @@ static Value *GetStoreValueForLoad(Value *SrcVal, unsigned Offset,
ShiftAmt = (StoreSize-LoadSize-Offset)*8;
if (ShiftAmt)
SrcVal = BinaryOperator::CreateLShr(SrcVal,
ConstantInt::get(SrcVal->getType(), ShiftAmt), "tmp", InsertPt);
SrcVal = Builder.CreateLShr(SrcVal, ShiftAmt, "tmp");
if (LoadSize != StoreSize)
SrcVal = new TruncInst(SrcVal, IntegerType::get(Ctx, LoadSize*8),
"tmp", InsertPt);
SrcVal = Builder.CreateTrunc(SrcVal, IntegerType::get(Ctx, LoadSize*8),
"tmp");
return CoerceAvailableValueToLoadType(SrcVal, LoadTy, InsertPt, TD);
}