[PATCH] D123588: [InstCombine] fix tests in fneg.ll

[Chenbing.Zheng via Phabricator via llvm-commits]

Chenbing.Zheng created this revision.
Chenbing.Zheng added reviewers: spatel, Krishnakariya, benshi001.
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Add flag 'nsz' in select, so that it can be fold to fabs.

In D101727 <https://reviews.llvm.org/D101727>, it fix Incorrect transformation of fabs, so I think
'nsz' should be added in select.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D123588

Files:
  llvm/test/Transforms/InstCombine/fneg.ll


Index: llvm/test/Transforms/InstCombine/fneg.ll
===================================================================
--- llvm/test/Transforms/InstCombine/fneg.ll
+++ llvm/test/Transforms/InstCombine/fneg.ll
@@ -714,18 +714,15 @@
   ret float %fneg1
 }
 
-; TODO: This should reduce to fneg-of-fabs.
-
 define float @fnabs(float %a) {
 ; CHECK-LABEL: @fnabs(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp olt float [[A:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[A_NEG:%.*]] = fneg fast float [[A]]
-; CHECK-NEXT:    [[FNEG1:%.*]] = select fast i1 [[CMP]], float [[A]], float [[A_NEG]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call nsz float @llvm.fabs.f32(float [[A:%.*]])
+; CHECK-NEXT:    [[FNEG1:%.*]] = fneg fast float [[TMP1]]
 ; CHECK-NEXT:    ret float [[FNEG1]]
 ;
   %fneg = fneg float %a
   %cmp = fcmp olt float %a, %fneg
-  %sel = select i1 %cmp, float %fneg, float %a
+  %sel = select nsz i1 %cmp, float %fneg, float %a
   %fneg1 = fneg fast float %sel
   ret float %fneg1
 }


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