Add fast paths to ScalarEvolution::getSizeOf and getOffsetOf, as

they're used a lot by getNodeForGEP, which can be called a lot.
This speeds up -iv-users by around 15% on several testcases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101083 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2010-04-12 23:03:26 +00:00
parent 8cc21cac89
commit 6ab10f69a9

View File

@ -2254,6 +2254,13 @@ const SCEV *ScalarEvolution::getUMinExpr(const SCEV *LHS,
}
const SCEV *ScalarEvolution::getSizeOfExpr(const Type *AllocTy) {
// If we have TargetData, we can bypass creating a target-independent
// constant expression and then folding it back into a ConstantInt.
// This is just a compile-time optimization.
if (TD)
return getConstant(TD->getIntPtrType(getContext()),
TD->getTypeAllocSize(AllocTy));
Constant *C = ConstantExpr::getSizeOf(AllocTy);
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
C = ConstantFoldConstantExpression(CE, TD);
@ -2271,6 +2278,13 @@ const SCEV *ScalarEvolution::getAlignOfExpr(const Type *AllocTy) {
const SCEV *ScalarEvolution::getOffsetOfExpr(const StructType *STy,
unsigned FieldNo) {
// If we have TargetData, we can bypass creating a target-independent
// constant expression and then folding it back into a ConstantInt.
// This is just a compile-time optimization.
if (TD)
return getConstant(TD->getIntPtrType(getContext()),
TD->getStructLayout(STy)->getElementOffset(FieldNo));
Constant *C = ConstantExpr::getOffsetOf(STy, FieldNo);
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
C = ConstantFoldConstantExpression(CE, TD);