[PATCH] D110488: [InstCombine] Canonicalize ((X & -X) - 1) --> (~X & (X - 1)) (PR51784)

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp:1424
+    Constant *AllOnes = ConstantInt::getAllOnesValue(RHS->getType());
+    return BinaryOperator::CreateAnd(Builder.CreateXor(A, AllOnes),
+                                     Builder.CreateAdd(A, AllOnes));
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spatel wrote:
> xbolva00 wrote:
> > Nondet output? Different evaluation order of args between compilers
> Good catch - yeah, use local variables to ensure that the xor and add are inserted in a fixed order.
yup - I've reverted and have a fix testing on wsl2 now


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  https://reviews.llvm.org/D110488/new/

https://reviews.llvm.org/D110488