Re: [PATCH] x86: Don't set AVX_U128_DIRTY when all bits are zero

2021-07-15 Thread Hongtao Liu via Gcc-patches
On Fri, Jul 16, 2021 at 1:30 AM H.J. Lu via Gcc-patches wrote: > > In a single SET, all bits of the source YMM/ZMM register are zero when > > 1. The source is contant zero. > 2. The source YMM/ZMM operand are defined from contant zero. > > and we don't set AVX_U128_DIRTY. > > gcc/ > > PR t

[PATCH] x86: Don't set AVX_U128_DIRTY when all bits are zero

2021-07-15 Thread H.J. Lu via Gcc-patches
In a single SET, all bits of the source YMM/ZMM register are zero when 1. The source is contant zero. 2. The source YMM/ZMM operand are defined from contant zero. and we don't set AVX_U128_DIRTY. gcc/ PR target/101456 * config/i386/i386.c (ix86_avx_u128_mode_needed): Don't set