Allow to fold vector load if there is more than one bitcast, so in the case:

%0 = load <8 x i16>* %dest
%1 = shufflevector <8 x i16> %0, <8 x i16> %in,
      <8 x i32> < i32 0, i32 1, i32 2, i32 3, i32 13, i32 undef, i32 14, i32 14>
store <8 x i16> %1, <8 x i16>* %dest

We get:
  vmovlpd (%eax), %xmm0, %xmm0

instead of:
  vmovaps (%eax), %xmm1
  vmovsd  %xmm1, %xmm0, %xmm0

No extra test-case is added. I just fixed the existing one
(also it uses FileCheck now).

llvm-svn: 166971

1 files changed, 4 insertions, 4 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 06b83297fea..b65fcf1bbe5 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -6438,17 +6438,17 @@ LowerVECTOR_SHUFFLE_128v4(ShuffleVectorSDNode *SVOp, SelectionDAG &DAG) {
 }
 
 static bool MayFoldVectorLoad(SDValue V) {
-  if (V.hasOneUse() && V.getOpcode() == ISD::BITCAST)
+  while (V.hasOneUse() && V.getOpcode() == ISD::BITCAST)
     V = V.getOperand(0);
+
   if (V.hasOneUse() && V.getOpcode() == ISD::SCALAR_TO_VECTOR)
     V = V.getOperand(0);
   if (V.hasOneUse() && V.getOpcode() == ISD::BUILD_VECTOR &&
       V.getNumOperands() == 2 && V.getOperand(1).getOpcode() == ISD::UNDEF)
     // BUILD_VECTOR (load), undef
     V = V.getOperand(0);
-  if (MayFoldLoad(V))
-    return true;
-  return false;
+
+  return MayFoldLoad(V);
 }
 
 // FIXME: the version above should always be used. Since there's