From d9bc309e9c08dd6b1db732c6b3d32ebbe6683851 Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev@redking.me.uk>
Date: Tue, 25 Oct 2016 22:01:09 +0000
Subject: [PATCH] [DAGCombiner] Enable (urem x, (shl pow2, y)) -> (and x, (add
 (shl pow2, y), -1)) combine for splatted vectors

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285129 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SelectionDAG/DAGCombiner.cpp |  6 ++--
 test/CodeGen/X86/combine-urem.ll         | 53 +++++---------------------------
 2 files changed, 11 insertions(+), 48 deletions(-)

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index f8953f0fb49..81fb69f517f 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -2482,9 +2482,9 @@ SDValue DAGCombiner::visitREM(SDNode *N) {
     }
     // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
     if (N1.getOpcode() == ISD::SHL) {
-      ConstantSDNode *SHC = getAsNonOpaqueConstant(N1.getOperand(0));
-      if (SHC && SHC->getAPIntValue().isPowerOf2()) {
-        APInt NegOne = APInt::getAllOnesValue(VT.getSizeInBits());
+      ConstantSDNode *SHC = isConstOrConstSplat(N1.getOperand(0));
+      if (SHC && !SHC->isOpaque() && SHC->getAPIntValue().isPowerOf2()) {
+        APInt NegOne = APInt::getAllOnesValue(VT.getScalarSizeInBits());
         SDValue Add =
             DAG.getNode(ISD::ADD, DL, VT, N1, DAG.getConstant(NegOne, DL, VT));
         AddToWorklist(Add.getNode());
diff --git a/test/CodeGen/X86/combine-urem.ll b/test/CodeGen/X86/combine-urem.ll
index c043db5b542..0dc10164a5c 100644
--- a/test/CodeGen/X86/combine-urem.ll
+++ b/test/CodeGen/X86/combine-urem.ll
@@ -88,57 +88,20 @@ define <4 x i32> @combine_vec_urem_by_shl_pow2a(<4 x i32> %x, <4 x i32> %y) {
 ; SSE:       # BB#0:
 ; SSE-NEXT:    pslld $23, %xmm1
 ; SSE-NEXT:    paddd {{.*}}(%rip), %xmm1
-; SSE-NEXT:    cvttps2dq %xmm1, %xmm2
-; SSE-NEXT:    pslld $2, %xmm2
-; SSE-NEXT:    pextrd $1, %xmm0, %eax
-; SSE-NEXT:    pextrd $1, %xmm2, %ecx
-; SSE-NEXT:    xorl %edx, %edx
-; SSE-NEXT:    divl %ecx
-; SSE-NEXT:    movl %edx, %ecx
-; SSE-NEXT:    movd %xmm0, %eax
-; SSE-NEXT:    movd %xmm2, %esi
-; SSE-NEXT:    xorl %edx, %edx
-; SSE-NEXT:    divl %esi
-; SSE-NEXT:    movd %edx, %xmm1
-; SSE-NEXT:    pinsrd $1, %ecx, %xmm1
-; SSE-NEXT:    pextrd $2, %xmm0, %eax
-; SSE-NEXT:    pextrd $2, %xmm2, %ecx
-; SSE-NEXT:    xorl %edx, %edx
-; SSE-NEXT:    divl %ecx
-; SSE-NEXT:    pinsrd $2, %edx, %xmm1
-; SSE-NEXT:    pextrd $3, %xmm0, %eax
-; SSE-NEXT:    pextrd $3, %xmm2, %ecx
-; SSE-NEXT:    xorl %edx, %edx
-; SSE-NEXT:    divl %ecx
-; SSE-NEXT:    pinsrd $3, %edx, %xmm1
-; SSE-NEXT:    movdqa %xmm1, %xmm0
+; SSE-NEXT:    cvttps2dq %xmm1, %xmm1
+; SSE-NEXT:    pslld $2, %xmm1
+; SSE-NEXT:    pcmpeqd %xmm2, %xmm2
+; SSE-NEXT:    paddd %xmm1, %xmm2
+; SSE-NEXT:    pand %xmm2, %xmm0
 ; SSE-NEXT:    retq
 ;
 ; AVX-LABEL: combine_vec_urem_by_shl_pow2a:
 ; AVX:       # BB#0:
 ; AVX-NEXT:    vpbroadcastd {{.*}}(%rip), %xmm2
 ; AVX-NEXT:    vpsllvd %xmm1, %xmm2, %xmm1
-; AVX-NEXT:    vpextrd $1, %xmm1, %ecx
-; AVX-NEXT:    vpextrd $1, %xmm0, %eax
-; AVX-NEXT:    xorl %edx, %edx
-; AVX-NEXT:    divl %ecx
-; AVX-NEXT:    movl %edx, %ecx
-; AVX-NEXT:    vmovd %xmm1, %esi
-; AVX-NEXT:    vmovd %xmm0, %eax
-; AVX-NEXT:    xorl %edx, %edx
-; AVX-NEXT:    divl %esi
-; AVX-NEXT:    vmovd %edx, %xmm2
-; AVX-NEXT:    vpinsrd $1, %ecx, %xmm2, %xmm2
-; AVX-NEXT:    vpextrd $2, %xmm1, %ecx
-; AVX-NEXT:    vpextrd $2, %xmm0, %eax
-; AVX-NEXT:    xorl %edx, %edx
-; AVX-NEXT:    divl %ecx
-; AVX-NEXT:    vpinsrd $2, %edx, %xmm2, %xmm2
-; AVX-NEXT:    vpextrd $3, %xmm1, %ecx
-; AVX-NEXT:    vpextrd $3, %xmm0, %eax
-; AVX-NEXT:    xorl %edx, %edx
-; AVX-NEXT:    divl %ecx
-; AVX-NEXT:    vpinsrd $3, %edx, %xmm2, %xmm0
+; AVX-NEXT:    vpcmpeqd %xmm2, %xmm2, %xmm2
+; AVX-NEXT:    vpaddd %xmm2, %xmm1, %xmm1
+; AVX-NEXT:    vpand %xmm1, %xmm0, %xmm0
 ; AVX-NEXT:    retq
   %1 = shl <4 x i32> <i32 4, i32 4, i32 4, i32 4>, %y
   %2 = urem <4 x i32> %x, %1
-- 
2.11.0