Perhaps this is a question for the gcc development list, but I thought I'd try here first. I am trying to figure out why GCC 12.1 generated object code is executing a hair slower than GCC 8.3.0 generated object code. I did run gcc with -fverbose-asm and -S, examined the assembly, and saw that -march=x86_64 -mtune=generic was used for compilation options. Reading the documentation. I see that -mtune=generic can change from GCC release to release based on the most prevalent processors in use at the time. I did poke around at the gcc source code and (gcc/config/i386/*) to see if I could figure out what changed from release to release and admit defeat. Does anyone have a quick rundown on what would have changed between GCC 8.3.0 and 12.1.0 in terms of what -mtune=generic does for optimizations? Thanks, Tom
