[llvm] r199553 - InstCombine: Make the (fmul X, -1.0) -> (fsub -0.0, X) transform handle vectors too.

[Benjamin Kramer]

Author: d0k
Date: Sat Jan 18 10:43:14 2014
New Revision: 199553

URL: http://llvm.org/viewvc/llvm-project?rev=199553&view=rev
Log:
InstCombine: Make the (fmul X, -1.0) -> (fsub -0.0, X) transform handle vectors too.

PR18532.

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
    llvm/trunk/test/Transforms/InstCombine/fmul.ll

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp?rev=199553&r1=199552&r2=199553&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp Sat Jan 18 10:43:14 2014
@@ -425,17 +425,15 @@ Instruction *InstCombiner::visitFMul(Bin
       if (Instruction *NV = FoldOpIntoPhi(I))
         return NV;
 
-    ConstantFP *C = dyn_cast<ConstantFP>(Op1);
-
     // (fmul X, -1.0) --> (fsub -0.0, X)
-    if (C && C->isExactlyValue(-1.0)) {
-      Instruction *RI = BinaryOperator::CreateFSub(
-        ConstantFP::getNegativeZero(C->getType()),
-        Op0);
+    if (match(Op1, m_SpecificFP(-1.0))) {
+      Constant *NegZero = ConstantFP::getNegativeZero(Op1->getType());
+      Instruction *RI = BinaryOperator::CreateFSub(NegZero, Op0);
       RI->copyFastMathFlags(&I);
       return RI;
     }
 
+    ConstantFP *C = dyn_cast<ConstantFP>(Op1);
     if (C && AllowReassociate && C->getValueAPF().isFiniteNonZero()) {
       // Let MDC denote an expression in one of these forms:
       // X * C, C/X, X/C, where C is a constant.

Modified: llvm/trunk/test/Transforms/InstCombine/fmul.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/fmul.ll?rev=199553&r1=199552&r2=199553&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/fmul.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/fmul.ll Sat Jan 18 10:43:14 2014
@@ -104,3 +104,12 @@ define float @test9(float %x) {
 ; CHECK: fsub
 }
 
+; PR18532
+define <4 x float> @test10(<4 x float> %x) {
+  %mul = fmul <4 x float> %x, <float -1.0, float -1.0, float -1.0, float -1.0>
+  ret <4 x float> %mul
+
+; CHECK-LABEL: @test10(
+; CHECK-NOT: fmul
+; CHECK: fsub
+}