Re: [PATCH] Optimize (ne:SI (subreg:QI (ashift:SI x 7) 0) 0) as (and:SI x 1).

On 10/10/23 08:41, Michael Matz wrote: On Tue, 10 Oct 2023, Roger Sayle wrote: This patch is the middle-end piece of an improvement to PRs 101955 and 106245, that adds a missing simplification to the RTL optimizers. This transformation is to simplify (char)(x << 7) != 0 as x & 1. Random

Re: [PATCH] Optimize (ne:SI (subreg:QI (ashift:SI x 7) 0) 0) as (and:SI x 1).

On Tue, 10 Oct 2023, Roger Sayle wrote: > > This patch is the middle-end piece of an improvement to PRs 101955 and > 106245, that adds a missing simplification to the RTL optimizers. > This transformation is to simplify (char)(x << 7) != 0 as x & 1. Random observation: So, why restrict to

Re: [PATCH] Optimize (ne:SI (subreg:QI (ashift:SI x 7) 0) 0) as (and:SI x 1).

On 10/10/23 06:28, Roger Sayle wrote: This patch is the middle-end piece of an improvement to PRs 101955 and 106245, that adds a missing simplification to the RTL optimizers. This transformation is to simplify (char)(x << 7) != 0 as x & 1. Technically, the cast can be any truncation, where

[PATCH] Optimize (ne:SI (subreg:QI (ashift:SI x 7) 0) 0) as (and:SI x 1).

This patch is the middle-end piece of an improvement to PRs 101955 and 106245, that adds a missing simplification to the RTL optimizers. This transformation is to simplify (char)(x << 7) != 0 as x & 1. Technically, the cast can be any truncation, where shift is by one less than the narrower