[Bug rtl-optimization/86107] [9 Regression] ICE: in ix86_mitigate_rop, at config/i386/i386.c:42301 with -O -funroll-loops -mavx5124fmaps -mmitigate-rop --param=hot-bb-frequency-fraction=1

[ubizjak at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86107

--- Comment #5 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to rsandifo@gcc.gnu.org from comment #4)

> > but should not fail verification even for !TARGET_INTER_UNIT_MOVES_TO_VEC
> > targets. As a matter of fact, the compilation works with -mtune=intel.
> 
> This is by design when the insn belongs to a block that is being
> optimised for speed rather than size.  It isn't recog per se that
> fails, but the validate_change stuff, which is designed for doing
> optional optimisations rather than required changes.

Please note that regrename_do_replace fails, since the mentioned instruction
does not validate, although the compiler just wants to rename %bx to %dx in
(insn 1264); a simple register rename should not make the new insn invalid.