[PATCH] D43160: [InstSimplify] allow exp/log simplifications with only 'reassoc' FMF

[Warren Ristow via Phabricator via llvm-commits]

wristow added a comment.

Code change LGTM.  A minor tweak to each test-change (to replace 'fast' with 'reassoc') would test it more precisely.



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Comment at: test/Transforms/InstSimplify/exp-intrinsic.ll:22
 ;
   %1 = call fast double @llvm.log.f64(double %a)
+  %2 = call reassoc double @llvm.exp.f64(double %1)
----------------
'reassoc' instead of 'fast' should also be all that's needed for the llvm.log.f64 call to enable this transformation.


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Comment at: test/Transforms/InstSimplify/exp2-intrinsic.ll:22
 ;
   %1 = call fast double @llvm.log2.f64(double %a)
+  %2 = call reassoc double @llvm.exp2.f64(double %1)
----------------
Again, 'reassoc' is all that's needed.


================
Comment at: test/Transforms/InstSimplify/log-intrinsic.ll:22
 ;
   %1 = call fast double @llvm.exp.f64(double %a)
+  %2 = call reassoc double @llvm.log.f64(double %1)
----------------
'reassoc' is all that's needed here, too.


================
Comment at: test/Transforms/InstSimplify/log2-intrinsic.ll:22
 ;
   %1 = call fast double @llvm.exp2.f64(double %a)
+  %2 = call reassoc double @llvm.log2.f64(double %1)
----------------
One last one where 'reassoc' is all that's needed.


https://reviews.llvm.org/D43160