Min-Yih Hsu 2291d0aba9 [DAGCombiner] Turn (neg (max x, (neg x))) into (min x, (neg x)) (#120666) ...

This pattern was originally spotted in 429.mcf by @topperc.

We already have a DAGCombiner pattern to turn `(neg (abs x))` into `(min
x, (neg x))`. But in some cases `(neg (max x, (neg x)))` is formed by an
expanded `abs` followed by a `neg` that is generated only after the
`abs` expansion. This patch adds a separate pattern to match cases like
this, as well as its inverse pattern: `(neg (min X, (neg X))) --> (max
X, (neg X))`.

This pattern is applicable to both signed and unsigned min/max.

2025-01-02 16:28:55 -08:00

507 KiB

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