[PATCH] D128591: Transforms: refactor pow(x, n) expansion where n is a constant integer value

[Sanjay Patel via Phabricator via llvm-commits]

spatel added inline comments.


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Comment at: llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp:1917
 
   // pow(x, n) -> x * x * x * ...
   const APFloat *ExpoF;
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Delete stale code comment.


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Comment at: llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp:1950
 
+    // pow(x, n) -> powi(x, n) if n is a constant signed integer value
     APSInt IntExpo(TLI->getIntSize(), /*isUnsigned=*/false);
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Add another line for the sqrt variant like:
 // pow(x, n) -> powi(x, n) * sqrt(x) if n has exactly a 0.5 fraction


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Comment at: llvm/test/CodeGen/AArch64/powi.ll:7
+
+define float @powi_f32(float %x) nounwind {
+; CHECK-LABEL: powi_f32:
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These tests results are independent of this patch, so this could be committed as a preliminary "NFC" patch. 

We intentionally don't have regression tests that check end-to-end results of IR optimization + codegen because we want focused/unit testing at this level. The end-to-end tests live in test-suite instead (and could begin from C source too).


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D128591/new/

https://reviews.llvm.org/D128591