[llvm] r284122 - [DAGCombiner] Add vector support to (mul (shl X, Y), Z) -> (shl (mul X, Z), Y) style combines

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Thu Oct 13 09:04:35 2016
New Revision: 284122

URL: http://llvm.org/viewvc/llvm-project?rev=284122&view=rev
Log:
[DAGCombiner] Add vector support to (mul (shl X, Y), Z) -> (shl (mul X, Z), Y) style combines

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    llvm/trunk/test/CodeGen/X86/combine-mul.ll

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=284122&r1=284121&r2=284122&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Thu Oct 13 09:04:35 2016
@@ -2148,11 +2148,10 @@ SDValue DAGCombiner::visitMUL(SDNode *N)
                                       getShiftAmountTy(N0.getValueType()))));
   }
 
-  APInt Val;
   // (mul (shl X, c1), c2) -> (mul X, c2 << c1)
-  if (N1IsConst && N0.getOpcode() == ISD::SHL &&
-      (ISD::isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
-       isa<ConstantSDNode>(N0.getOperand(1)))) {
+  if (N0.getOpcode() == ISD::SHL &&
+      isConstantOrConstantVector(N1) &&
+      isConstantOrConstantVector(N0.getOperand(1))) {
     SDValue C3 = DAG.getNode(ISD::SHL, SDLoc(N), VT, N1, N0.getOperand(1));
     AddToWorklist(C3.getNode());
     return DAG.getNode(ISD::MUL, SDLoc(N), VT, N0.getOperand(0), C3);
@@ -2162,14 +2161,14 @@ SDValue DAGCombiner::visitMUL(SDNode *N)
   // use.
   {
     SDValue Sh(nullptr, 0), Y(nullptr, 0);
+
     // Check for both (mul (shl X, C), Y)  and  (mul Y, (shl X, C)).
     if (N0.getOpcode() == ISD::SHL &&
-        (ISD::isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
-         isa<ConstantSDNode>(N0.getOperand(1))) &&
+        isConstantOrConstantVector(N0.getOperand(1)) &&
         N0.getNode()->hasOneUse()) {
       Sh = N0; Y = N1;
     } else if (N1.getOpcode() == ISD::SHL &&
-               isa<ConstantSDNode>(N1.getOperand(1)) &&
+               isConstantOrConstantVector(N1.getOperand(1)) &&
                N1.getNode()->hasOneUse()) {
       Sh = N1; Y = N0;
     }

Modified: llvm/trunk/test/CodeGen/X86/combine-mul.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/combine-mul.ll?rev=284122&r1=284121&r2=284122&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/combine-mul.ll (original)
+++ llvm/trunk/test/CodeGen/X86/combine-mul.ll Thu Oct 13 09:04:35 2016
@@ -146,7 +146,6 @@ define <4 x i32> @combine_vec_mul_shl_co
 ;
 ; AVX-LABEL: combine_vec_mul_shl_const:
 ; AVX:       # BB#0:
-; AVX-NEXT:    vpsllvd {{.*}}(%rip), %xmm0, %xmm0
 ; AVX-NEXT:    vpmulld {{.*}}(%rip), %xmm0, %xmm0
 ; AVX-NEXT:    retq
   %1 = shl <4 x i32> %x, <i32 1, i32 2, i32 8, i32 16>
@@ -164,8 +163,8 @@ define <4 x i32> @combine_vec_mul_shl_on
 ;
 ; AVX-LABEL: combine_vec_mul_shl_oneuse0:
 ; AVX:       # BB#0:
-; AVX-NEXT:    vpsllvd {{.*}}(%rip), %xmm0, %xmm0
 ; AVX-NEXT:    vpmulld %xmm1, %xmm0, %xmm0
+; AVX-NEXT:    vpsllvd {{.*}}(%rip), %xmm0, %xmm0
 ; AVX-NEXT:    retq
   %1 = shl <4 x i32> %x, <i32 1, i32 2, i32 8, i32 16>
   %2 = mul <4 x i32> %1, %y
@@ -181,8 +180,8 @@ define <4 x i32> @combine_vec_mul_shl_on
 ;
 ; AVX-LABEL: combine_vec_mul_shl_oneuse1:
 ; AVX:       # BB#0:
+; AVX-NEXT:    vpmulld %xmm1, %xmm0, %xmm0
 ; AVX-NEXT:    vpsllvd {{.*}}(%rip), %xmm0, %xmm0
-; AVX-NEXT:    vpmulld %xmm0, %xmm1, %xmm0
 ; AVX-NEXT:    retq
   %1 = shl <4 x i32> %x, <i32 1, i32 2, i32 8, i32 16>
   %2 = mul <4 x i32> %y, %1