https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104581
--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Biener <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:fe79d652c96b53384ddfa43e312cb0010251391b commit r12-7293-gfe79d652c96b53384ddfa43e312cb0010251391b Author: Richard Biener <rguent...@suse.de> Date: Thu Feb 17 14:40:16 2022 +0100 target/104581 - compile-time regression in mode-switching The x86 backend piggy-backs on mode-switching for insertion of vzeroupper. A recent improvement there was implemented in a way to walk possibly the whole basic-block for all DF reg def definitions in its mode_needed hook which is called for each instruction in a basic-block during mode-switching local analysis. The following mostly reverts this improvement. It needs to be re-done in a way more consistent with a local dataflow which probably means making targets aware of the state of the local dataflow analysis. 2022-02-17 Richard Biener <rguent...@suse.de> PR target/104581 * config/i386/i386.cc (ix86_avx_u128_mode_source): Remove. (ix86_avx_u128_mode_needed): Return AVX_U128_DIRTY instead of calling ix86_avx_u128_mode_source which would eventually have returned AVX_U128_ANY in some very special case. * gcc.target/i386/pr101456-1.c: XFAIL.
