Enhance constant folding of bitcast operations on vectors of floats.

Add getAllOnesValue of FP numbers to Constants and APFloat.
Add more tests.

llvm-svn: 125776

3 files changed, 14 insertions, 3 deletions

diff --git a/llvm/lib/Support/APFloat.cpp b/llvm/lib/Support/APFloat.cpp
index 6d018afa3f6..e765ba0a27b 100644
--- a/llvm/lib/Support/APFloat.cpp
+++ b/llvm/lib/Support/APFloat.cpp
@@ -3197,6 +3197,12 @@ APFloat::initFromAPInt(const APInt& api, bool isIEEE)
     llvm_unreachable(0);
 }
 
+APFloat
+APFloat::getAllOnesValue(unsigned BitWidth, bool isIEEE)
+{
+  return APFloat(APInt::getAllOnesValue(BitWidth), isIEEE);
+}
+
 APFloat APFloat::getLargest(const fltSemantics &Sem, bool Negative) {
   APFloat Val(Sem, fcNormal, Negative);
 
diff --git a/llvm/lib/VMCore/ConstantFold.cpp b/llvm/lib/VMCore/ConstantFold.cpp
index c8292c6d612..573efb7e573 100644
--- a/llvm/lib/VMCore/ConstantFold.cpp
+++ b/llvm/lib/VMCore/ConstantFold.cpp
@@ -43,8 +43,7 @@ using namespace llvm;
 static Constant *BitCastConstantVector(ConstantVector *CV,
                                        const VectorType *DstTy) {
 
-  if (CV->isAllOnesValue() && DstTy->getElementType()->isIntegerTy())
-      return Constant::getAllOnesValue(DstTy);
+  if (CV->isAllOnesValue()) return Constant::getAllOnesValue(DstTy);
   if (CV->isNullValue()) return Constant::getNullValue(DstTy);
 
   // If this cast changes element count then we can't handle it here:
diff --git a/llvm/lib/VMCore/Constants.cpp b/llvm/lib/VMCore/Constants.cpp
index cac37cbcc38..a2ac768d221 100644
--- a/llvm/lib/VMCore/Constants.cpp
+++ b/llvm/lib/VMCore/Constants.cpp
@@ -93,7 +93,13 @@ Constant *Constant::getAllOnesValue(const Type *Ty) {
   if (const IntegerType *ITy = dyn_cast<IntegerType>(Ty))
     return ConstantInt::get(Ty->getContext(),
                             APInt::getAllOnesValue(ITy->getBitWidth()));
-  
+
+  if (Ty->isFloatingPointTy()) {
+    APFloat FL = APFloat::getAllOnesValue(Ty->getPrimitiveSizeInBits(),
+                                          !Ty->isPPC_FP128Ty());
+    return ConstantFP::get(Ty->getContext(), FL);
+  }
+
   SmallVector<Constant*, 16> Elts;
   const VectorType *VTy = cast<VectorType>(Ty);
   Elts.resize(VTy->getNumElements(), getAllOnesValue(VTy->getElementType()));