[llvm] r343041 - [InstCombine] add fneg variation of shuffle-binop fold; NFC

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Tue Sep 25 15:48:58 2018
New Revision: 343041

URL: http://llvm.org/viewvc/llvm-project?rev=343041&view=rev
Log:
[InstCombine] add fneg variation of shuffle-binop fold; NFC

If the fsub in this pattern was replaced by an actual fneg
instruction, we would need to add a fold to recognize that
because fneg would not be a binop.

Modified:
    llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll

Modified: llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll?rev=343041&r1=343040&r2=343041&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll Tue Sep 25 15:48:58 2018
@@ -913,6 +913,17 @@ define <2 x float> @fsub_splat_constant1
   ret <2 x float> %r
 }
 
+define <2 x float> @fneg(<2 x float> %x) {
+; CHECK-LABEL: @fneg(
+; CHECK-NEXT:    [[TMP1:%.*]] = fsub <2 x float> <float -0.000000e+00, float undef>, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = shufflevector <2 x float> [[TMP1]], <2 x float> undef, <2 x i32> zeroinitializer
+; CHECK-NEXT:    ret <2 x float> [[R]]
+;
+  %splat = shufflevector <2 x float> %x, <2 x float> undef, <2 x i32> zeroinitializer
+  %r = fsub <2 x float> <float -0.0, float -0.0>, %splat
+  ret <2 x float> %r
+}
+
 define <2 x float> @fmul_splat_constant(<2 x float> %x) {
 ; CHECK-LABEL: @fmul_splat_constant(
 ; CHECK-NEXT:    [[TMP1:%.*]] = fmul <2 x float> [[X:%.*]], <float 4.200000e+01, float undef>