• ozymandias117@lemmy.world
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      1 day ago

      -O2 vs -O3 adds -fgcse-after-reload -fipa-cp-clone -floop-interchange -floop-unroll-and-jam -fpeel-loops -fpredictive-commoning -fsplit-loops -fsplit-paths -ftree-loop-distribution -ftree-partial-pre -funswitch-loops -fvect-cost-model=dynamic -fversion-loops-for-strides

      I don’t think any of these optimizations require more modern hardware?

      • themoken@startrek.website
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        1 day ago

        Right. GCC -f optimizations are basically like “how hard are we going to try to be clever” and are, I believe, orthogonal to the actual instructions used. Machine dependent args start with -m, like -march or -mavx etc.

        • ozymandias117@lemmy.world
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          1 day ago

          I was reasonably certain, but left it open in case OP knew of some edge case where flags that are intended to be machine independent caused bugs on different architectures