https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83397
Andi Kleen <andi-gcc at firstfloor dot org> changed:
What |Removed |Added
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CC| |andi-gcc at firstfloor dot org
--- Comment #4 from Andi Kleen <andi-gcc at firstfloor dot org> ---
If you want to skip the rax setup you can use -mskip-rax-setup
But in general it's dangerous because old gcc compiled code can jump to random
locations if a real varargs function gets called with undefined rax
