https://sourceware.org/bugzilla/show_bug.cgi?id=27397
--- Comment #8 from Sergei Trofimovich <slyfox at inbox dot ru> --- (In reply to H.J. Lu from comment #7) > (In reply to Sergei Trofimovich from comment #6) > > (In reply to H.J. Lu from comment #5) > > > Created attachment 13220 [details] > > > An updated patch > > > > > > Try this. > > > > The user reports it's building fine for them on i486: > > https://bugs.gentoo.org/770061#c26 > > > > AFAIU event with the patch ./configure --host=i686-pc-linux-gnu if ran on > > pre-sse2 CPU, right? > > SSE2 isn't the issue. The multi-byte NOP is the issue. Oh, I thought these multibyte NOP come from SSE2 encoding. I'd like to understand why then these NOPs crash the program with SIGILL. Looking at endbr32 instruction as an example: "F3 0F 1E FB". Do I understand correctly it's supposed to be decoded by old CPUs as: prefix=F3 (REP) escape="0F 1E" (Reserved-NOP) modrm(?)=FB Do you know when these 'Reserved-NOP' were introduced as valid instruction to IA-32? I wonder why K6-III can't handle it: is it a CPU bug (imprecise implementation of reserved NOPs) or it was introduced later. -- You are receiving this mail because: You are on the CC list for the bug.
