[PATCH] D92739: [ValueTracking] Branch on poison is UB

[Nikita Popov via Phabricator via llvm-commits]

nikic added inline comments.


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Comment at: llvm/test/Transforms/LoopUnroll/runtime-small-upperbound.ll:3
 ; RUN: opt -S -loop-unroll -unroll-runtime %s -o - | FileCheck %s
-; RUN: opt -S -loop-unroll -unroll-runtime -unroll-max-upperbound=6 %s -o - | FileCheck %s --check-prefix=UPPER
+; RUN: opt -S -loop-unroll -unroll-runtime -unroll-max-upperbound=4 %s -o - | FileCheck %s --check-prefix=UPPER
 
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There is a comment below that says:

> ; Check that loop in hoge_5, with a runtime upperbound of 5, is unrolled when -unroll-max-upperbound=4

But the option actually used `-unroll-max-upperbound=6`. Previously SCEV didn't realize that the upperbound is actually 5, so this worked out fine. Now that it does, we have to use the correct value for the option.


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Comment at: llvm/test/Transforms/LoopVectorize/consecutive-ptr-uniforms.ll:66
   %tmp3 = add i32 %tmp0, %tmp2
-  %i.next = add nuw nsw i64 %i, -1
+  %i.next = add nsw i64 %i, -1
   %cond = icmp sgt i64 %i.next, 0
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An add of `-1` can clearly not be nuw. Presumably someone manually adjusted the `forward` case to go in the reverse direction, but retained the no longer applicable nuw flag.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D92739/new/

https://reviews.llvm.org/D92739