[PATCH] D102116: [LoopIdiom] 'logical right-shift until zero' ('count active bits') "on steroids" idiom recognition.

[Roman Lebedev via llvm-commits]

Thanks, fixed in aa3dac95edbfb892b6236341b431b222f7bd0926!
Roman

On Mon, May 24, 2021 at 9:26 AM Mikael Holmén via Phabricator
<reviews at reviews.llvm.org> wrote:
>
> uabelho added a comment.
>
> Hi,
>
> THere seems to be something problematic with this patch.
> With
>
>   opt -enable-new-pm=0 -o /dev/null bbi-56362_2.ll -loop-idiom
>
> I get
>
>   Instruction does not dominate all uses!
>     %1 = load i16, i16* getelementptr inbounds ({ i16, i16 }, { i16, i16 }* @v_92, i32 0, i32 0), align 1
>     %.numleadingzeros = call i16 @llvm.ctlz.i16(i16 %1, i1 false)
>   in function main
>
> and with
>
>   opt -enable-new-pm=1 -o /dev/null bbi-56362_2.ll -loop-idiom
>
> I get
>
>   opt: ../lib/Transforms/Scalar/LoopPassManager.cpp:253: auto llvm::FunctionToLoopPassAdaptor::run(llvm::Function &, llvm::FunctionAnalysisManager &)::(anonymous class)::operator()(llvm::StringRef, llvm::Any) const: Assertion `L->isRecursivelyLCSSAForm(LAR.DT, LI) && "Loops must remain in LCSSA form!"' failed.
>
> F17004376: bbi-56362_2.ll <https://reviews.llvm.org/F17004376>
>
>
> Repository:
>   rG LLVM Github Monorepo
>
> CHANGES SINCE LAST ACTION
>   https://reviews.llvm.org/D102116/new/
>
> https://reviews.llvm.org/D102116
>