[llvm] r207352 - SelectionDAG: Aggressively fold shuffles of constant splats.

[Benjamin Kramer]

Author: d0k
Date: Sun Apr 27 06:41:06 2014
New Revision: 207352

URL: http://llvm.org/viewvc/llvm-project?rev=207352&view=rev
Log:
SelectionDAG: Aggressively fold shuffles of constant splats.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    llvm/trunk/test/CodeGen/X86/vector-idiv.ll

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp?rev=207352&r1=207351&r2=207352&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp Sun Apr 27 06:41:06 2014
@@ -1441,6 +1441,11 @@ SDValue SelectionDAG::getVectorShuffle(E
   if (Identity && NElts)
     return N1;
 
+  // Shuffling a constant splat doesn't change the result.
+  if (N2Undef && N1.getOpcode() == ISD::BUILD_VECTOR)
+    if (cast<BuildVectorSDNode>(N1)->getConstantSplatValue())
+      return N1;
+
   FoldingSetNodeID ID;
   SDValue Ops[2] = { N1, N2 };
   AddNodeIDNode(ID, ISD::VECTOR_SHUFFLE, getVTList(VT), Ops, 2);

Modified: llvm/trunk/test/CodeGen/X86/vector-idiv.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/vector-idiv.ll?rev=207352&r1=207351&r2=207352&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/vector-idiv.ll (original)
+++ llvm/trunk/test/CodeGen/X86/vector-idiv.ll Sun Apr 27 06:41:06 2014
@@ -115,6 +115,7 @@ define <4 x i32> @test8(<4 x i32> %a) {
 ; SSE-LABEL: test8:
 ; SSE: pmuldq
 ; SSE: pshufd	$57
+; SSE-NOT: pshufd	$57
 ; SSE: pmuldq
 ; SSE: shufps	$-35
 ; SSE: pshufd	$-40
@@ -126,6 +127,7 @@ define <4 x i32> @test8(<4 x i32> %a) {
 ; AVX-LABEL: test8:
 ; AVX: vpmuldq
 ; AVX: vpshufd	$57
+; AVX-NOT: vpshufd	$57
 ; AVX: vpmuldq
 ; AVX: vshufps	$-35
 ; AVX: vpshufd	$-40
@@ -140,7 +142,7 @@ define <8 x i32> @test9(<8 x i32> %a) {
   ret <8 x i32> %div
 
 ; AVX-LABEL: test9:
-; AVX: vpermd
+; AVX: vpbroadcastd
 ; AVX: vpmuldq
 ; AVX: vshufps	$-35
 ; AVX: vpmuldq
@@ -157,7 +159,7 @@ define <8 x i32> @test10(<8 x i32> %a) {
   ret <8 x i32> %rem
 
 ; AVX-LABEL: test10:
-; AVX: vpermd
+; AVX: vpbroadcastd
 ; AVX: vpmuludq
 ; AVX: vshufps	$-35
 ; AVX: vpmuludq
@@ -174,7 +176,7 @@ define <8 x i32> @test11(<8 x i32> %a) {
   ret <8 x i32> %rem
 
 ; AVX-LABEL: test11:
-; AVX: vpermd
+; AVX: vpbroadcastd
 ; AVX: vpmuldq
 ; AVX: vshufps	$-35
 ; AVX: vpmuldq