[PATCH] D145510: [SCEV] Fix finite loop non-strict predicate simplification (PR60944)

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

I'm seeing a regression for the following loop:

  define void @foo1(ptr %A, i32 %m, i32 %n) mustprogress {
  entry:
    br label %for.body
  
  for.body:                                         ; preds = %entry, %for.body
    %i.06 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
    %inc = add i32 %i.06, 1
    %cmp.not = icmp ugt i32 %inc, %m
    br i1 %cmp.not, label %for.end, label %for.body
  
  for.end:                                          ; preds = %for.body
    ret void
  }

We used to produce a backedge-taken count of `%m`, but now we produce `(-1 + (1 umax (1 + %m)))`.


Repository:
  rG LLVM Github Monorepo

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https://reviews.llvm.org/D145510