https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93934
--- Comment #18 from Uroš Bizjak <ubizjak at gmail dot com> --- The following patch fixes the PR, see the comment inline: --cut here-- diff --git a/gcc/config/i386/i386-expand.c b/gcc/config/i386/i386-expand.c index 6e2b7920d2b..b87490fe544 100644 --- a/gcc/config/i386/i386-expand.c +++ b/gcc/config/i386/i386-expand.c @@ -4094,6 +4094,15 @@ ix86_expand_fp_movcc (rtx operands[]) && !TARGET_64BIT)) return false; + /* Disable SFmode and DFmode x87 FCMOV with trapping math + to prevent speculative load using FLDL/FLDS from uninitialized + memory location, which can contain sNaN value. FLDL/FLDS traps + on sNaN, see PR93934. */ + + if ((mode == SFmode || mode == DFmode) + && flag_trapping_math) + return false; + /* The floating point conditional move instructions don't directly support conditions resulting from a signed integer comparison. */ --cut here--