[PATCH] D79409: [InstCombine] Remove hasNoInfs check for pow(C, y) -> exp2(log2(C)*y)

[Jay Foad via Phabricator via llvm-commits]

foad added a comment.

In D79409#2023671 <https://reviews.llvm.org/D79409#2023671>, @evandro wrote:

> `exp2(log2(x) * -∞)` → `exp2(±∞)` → ∞ if `x < 2` or 0 if `x > 2`
>  `exp2(log2(x) * +∞)` → `exp2(±∞)` → 0 if `x < 2` or ∞ if `x > 2`


No, the sign of log2(x) depends on whether x is less or greater than 1, not less or greater than 2.


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https://reviews.llvm.org/D79409