Re: [PATCH] i386: Don't emit pushf; pop for __builtin_ia32_readeflags_u* with unused lhs [PR104971]

2022-03-19 Thread Uros Bizjak via Gcc-patches
On Sat, Mar 19, 2022 at 8:39 AM Jakub Jelinek wrote: > > Hi! > > __builtin_ia32_readeflags_u* aren't marked const or pure I think > intentionally, so that they aren't CSEd from different regions of a function > etc. because we don't and can't easily track all dependencies between > it and

[PATCH] i386: Don't emit pushf;pop for __builtin_ia32_readeflags_u* with unused lhs [PR104971]

2022-03-19 Thread Jakub Jelinek via Gcc-patches
Hi! __builtin_ia32_readeflags_u* aren't marked const or pure I think intentionally, so that they aren't CSEd from different regions of a function etc. because we don't and can't easily track all dependencies between it and surrounding code (if somebody looks at the condition flags, it is