This is needed to benchmark instruction that touch EFLAGS (e.g. STD: set direction flag).
our internal buildbots at Azul has failed because of an older assembler. We’ve taken in all commits/reverts/relands w.r.t this change upto Nov 4th.
The specific failure is:
/tmp/cc2lBtEi.s: Assembler messages:
/tmp/cc2lBtEi.s:541: Error: no such instruction: `fxsave64 16(%rax)'
/tmp/cc2lBtEi.s:566: Error: no such instruction: `fxrstor64 16(%rdi)'
/tmp/cc2lBtEi.s:592: Error: no such instruction: `fxrstor64 16(%rdi)'
make: *** [tools/llvm-exegesis/lib/X86/CMakeFiles/LLVMExegesisX86.dir/Target.cpp.o] Error 1
Any suggestions to fix this apart from an upgrade (which seems to be a very invasive change on our machines)?
We use the GNU assembler and it is configured for 64 bit machines. Here's the details from one of the machines:
as --version GNU assembler version 126.96.36.199.2-5.47.el6_9.1 20100205 Copyright 2009 Free Software Foundation, Inc. This program is free software; you may redistribute it under the terms of the GNU General Public License version 3 or later. This program has absolutely no warranty. This assembler was configured for a target of `x86_64-redhat-linux'
Also, note that I tagged this against the incorrect review. The change causing the failures is https://reviews.llvm.org/D90592. I'm going to paste this there and we can continue discussion there.