Fix a problem with DAGCombine on 64b targets where folding

extracts + build_vector into a shuffle would fail, because the
type of the new build_vector would not be legal.  Try harder to
create a legal build_vector type.  Note: this will be totally 
irrelevant once vector_shuffle no longer takes a build_vector for
shuffle mask.

New:
_foo:
	xorps	%xmm0, %xmm0
	xorps	%xmm1, %xmm1
	subps	%xmm1, %xmm1
	mulps	%xmm0, %xmm1
	addps	%xmm0, %xmm1
	movaps	%xmm1, 0

Old:
_foo:
	xorps	%xmm0, %xmm0
	movss	%xmm0, %xmm1
	xorps	%xmm2, %xmm2
	unpcklps	%xmm1, %xmm2
	pshufd	$80, %xmm1, %xmm1
	unpcklps	%xmm1, %xmm2
	pslldq	$16, %xmm2
	pshufd	$57, %xmm2, %xmm1
	subps	%xmm0, %xmm1
	mulps	%xmm0, %xmm1
	addps	%xmm0, %xmm1
	movaps	%xmm1, 0



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65791 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 4b3935c217..788ffb6ad0 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -5257,7 +5257,8 @@ SDValue DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
     }
 
     // Add count and size info.
-    MVT BuildVecVT = MVT::getVectorVT(TLI.getPointerTy(), NumElts);
+    MVT IndexVT = MVT::getIntegerVT(EltType.getSizeInBits());
+    MVT BuildVecVT = MVT::getVectorVT(IndexVT, NumElts);
     if (!TLI.isTypeLegal(BuildVecVT) && LegalTypes)
       return SDValue();