Fix a regression from r125393;

It caused a crash in MultiSource/Benchmarks/Bullet.
Opt hit an assertion with "opt -std-compile-opts" because
Constant::getAllOnesValue doesn't know how to handle floats.

This patch added a test to reproduce the problem and a check that the
destination vector is of integer type.

Thank you Benjamin!

llvm-svn: 125459

2 files changed, 19 insertions, 2 deletions

diff --git a/llvm/lib/VMCore/ConstantFold.cpp b/llvm/lib/VMCore/ConstantFold.cpp
index 0ec343f07d2..1b50c4aa9dd 100644
--- a/llvm/lib/VMCore/ConstantFold.cpp
+++ b/llvm/lib/VMCore/ConstantFold.cpp
@@ -43,7 +43,8 @@ using namespace llvm;
 static Constant *BitCastConstantVector(ConstantVector *CV,
                                        const VectorType *DstTy) {
 
-  if (CV->isAllOnesValue()) return Constant::getAllOnesValue(DstTy);
+  if (CV->isAllOnesValue() && DstTy->getElementType()->isIntegerTy())
+      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/test/Transforms/InstCombine/bitcast-vec-uniform.ll b/llvm/test/Transforms/InstCombine/bitcast-vec-uniform.ll
index 1fba1632693..ef428894e72 100644
--- a/llvm/test/Transforms/InstCombine/bitcast-vec-uniform.ll
+++ b/llvm/test/Transforms/InstCombine/bitcast-vec-uniform.ll
@@ -1,14 +1,30 @@
-; RUN: opt < %s -instcombine -S | not grep bitcast
+; RUN: opt < %s -instcombine -S | FileCheck %s
 
+; CHECK: @a
+; CHECK-NOT: bitcast
+; CHECK: ret
 define <4 x i32> @a(<1 x i64> %y) {
   %c = bitcast <2 x i64> <i64 0, i64 0> to <4 x i32>
   ret <4 x i32> %c
 }
 
+; CHECK: @b
+; CHECK: bitcast
+; CHECK: ret
+
 define <4 x i32> @b(<1 x i64> %y) {
   %c = bitcast <2 x i64> <i64 -1, i64 -1> to <4 x i32>
   ret <4 x i32> %c
 }
 
+; CHECK: @foo
+; CHECK: bitcast
+
+; from MultiSource/Benchmarks/Bullet
+define <2 x float> @foo() {
+  %cast = bitcast i64 -1 to <2 x float>
+  ret <2 x float> %cast
+}
+