[PATCH] D154677: [InstCombine] Add tests for folding `fmul`/`fdiv` by Pow2 to `add`/`sub` of exp; NFC

[Noah Goldstein via Phabricator via llvm-commits]

goldstein.w.n added inline comments.


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Comment at: llvm/test/Transforms/InstCombine/fmul-and-fdiv-by-int-pow2.ll:14
+  %conv = uitofp i64 %shl to double
+  %mul = fmul double 9.000000e+00, %conv
+  ret double %mul
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arsenm wrote:
> Add some tests that show flag preservation on fmul/fdiv
Hmm? Can you link to example or reference?


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Comment at: llvm/test/Transforms/InstCombine/fmul-and-fdiv-by-int-pow2.ll:182
+;
+  %shl = shl nuw i16 1, %cnt
+  %conv = uitofp i16 %shl to half
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arsenm wrote:
> Are the nuws relevant?
They get added anyways for `(shl 1, cnt)`. They are used to make non-zero status easy to determine.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D154677/new/

https://reviews.llvm.org/D154677