Don't insert 128-bit UNDEF into 256-bit vectors. Just keep the 256-bit vector. Origin...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158792 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index dec8d07d99f2317bdf5c1fd19a8f229e1a9ae4f8..2576821d39f35a4b1aa3f9c5c93686c6eb73dfcc 100644 (file)
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -99,6 +99,10 @@ static SDValue Extract128BitVector(SDValue Vec, unsigned IdxVal,
 static SDValue Insert128BitVector(SDValue Result, SDValue Vec,
                                   unsigned IdxVal, SelectionDAG &DAG,
                                   DebugLoc dl) {
+  // Inserting UNDEF is Result
+  if (Vec.getOpcode() == ISD::UNDEF)
+    return Result;
+
   EVT VT = Vec.getValueType();
   assert(VT.getSizeInBits() == 128 && "Unexpected vector size!");
 
@@ -114,9 +118,8 @@ static SDValue Insert128BitVector(SDValue Result, SDValue Vec,
                                * ElemsPerChunk);
 
   SDValue VecIdx = DAG.getConstant(NormalizedIdxVal, MVT::i32);
-  Result = DAG.getNode(ISD::INSERT_SUBVECTOR, dl, ResultVT, Result, Vec,
-                       VecIdx);
-  return Result;
+  return DAG.getNode(ISD::INSERT_SUBVECTOR, dl, ResultVT, Result, Vec,
+                     VecIdx);
 }
 
 /// Concat two 128-bit vectors into a 256 bit vector using VINSERTF128

diff --git a/test/CodeGen/X86/avx-shuffle-x86_32.ll b/test/CodeGen/X86/avx-shuffle-x86_32.ll
index 5268ec3a56cde0241ea4e6095073af675f7570f6..e203c4ed0298f1ccc00f6acdcb3da8f43b25b9f6 100755 (executable)
--- a/test/CodeGen/X86/avx-shuffle-x86_32.ll
+++ b/test/CodeGen/X86/avx-shuffle-x86_32.ll
@@ -4,5 +4,5 @@ define <4 x i64> @test1(<4 x i64> %a) nounwind {
  %b = shufflevector <4 x i64> %a, <4 x i64> undef, <4 x i32> <i32 1, i32 3, i32 5, i32 7>
  ret <4 x i64>%b
  ; CHECK: test1:
- ; CHECK: vinsertf128
+ ; CHECK-NOT: vinsertf128
  }

diff --git a/test/CodeGen/X86/avx-shuffle.ll b/test/CodeGen/X86/avx-shuffle.ll
index f1debffd1118af2aff3c297177963d32378cd44d..edfe4ab6c77e0bb86fa586ab3da551b4874dc349 100644 (file)
--- a/test/CodeGen/X86/avx-shuffle.ll
+++ b/test/CodeGen/X86/avx-shuffle.ll
@@ -219,3 +219,11 @@ define <16 x i16> @narrow(<16 x i16> %a) nounwind alwaysinline {
   %t = shufflevector <16 x i16> %a, <16 x i16> undef, <16 x i32> <i32 2, i32 3, i32 undef, i32 1, i32 6, i32 7, i32 4, i32 5, i32 10, i32 11, i32 8, i32 undef, i32 14, i32 15, i32 undef, i32 undef>
   ret <16 x i16> %t
 }
+
+;CHECK: test17
+;CHECK-NOT: vinsertf128
+;CHECK: ret
+define   <8 x float> @test17(<4 x float> %y) {
+  %x = shufflevector <4 x float> %y, <4 x float> undef, <8 x i32> <i32 undef, i32 1, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>
+  ret <8 x float> %x
+}