Add constant folding support for bitcasts of splat vectors to integers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138206 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index d74d7e8..7a8c703 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -46,7 +46,16 @@
static Constant *FoldBitCast(Constant *C, Type *DestTy,
const TargetData &TD) {
- // This only handles casts to vectors currently.
+ ConstantVector *CV = dyn_cast<ConstantVector>(C);
+ IntegerType *IntVTy = dyn_cast<IntegerType>(DestTy);
+ // When casting vectors to scalar integers, catch the
+ // obvious splat cases.
+ if (IntVTy && CV) {
+ if (CV->isNullValue()) return ConstantInt::getNullValue(IntVTy);
+ if (CV->isAllOnesValue()) return ConstantInt::getAllOnesValue(IntVTy);
+ }
+
+ // The code below only handles casts to vectors currently.
VectorType *DestVTy = dyn_cast<VectorType>(DestTy);
if (DestVTy == 0)
return ConstantExpr::getBitCast(C, DestTy);
@@ -59,7 +68,6 @@
}
// If this is a bitcast from constant vector -> vector, fold it.
- ConstantVector *CV = dyn_cast<ConstantVector>(C);
if (CV == 0)
return ConstantExpr::getBitCast(C, DestTy);