https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70064
--- Comment #7 from Zdenek Sojka <zsojka at seznam dot cz> --- (In reply to Uroš Bizjak from comment #4) > (In reply to Zdenek Sojka from comment #0) > > Created attachment 37854 [details] > > autoreduced testcase > > > > The testcase is likely very fragile due to the set of compiler flags and > > quite big testcase itself. Neither seems to be easily reducible. > > > > Output: > > $ i686-pc-linux-gnu-gcc -Os -march=athlon-tbird -fPIC -fsched-pressure > > -fsched-stalled-insns -fschedule-insns -fno-tree-reassoc > > -momit-leaf-frame-pointer -mpclmul -mred-zone -mno-stv > > -fira-algorithm=priority --param=max-sched-ready-insns=0 testcase.c > > -Wno-psabi > > Oh... Red zone is not allowed on x86_32 linux. Ok, thanks, I thought -mred-zone is a no-op, if unsupported; but apparently it is not. I wonder if the testcase fails just because the red zone is unsupported on the architecture, or if there is actually a bug that data in the red zone are not invalidated due to the call. (technically, one can define his own x86 ABI with -mred-zone and, say, -mregparm=3 (which is supported))