[Windows] allow clang to build tailcall vm, use __preserve_none for Call VM if available with msvc#21563
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henderkes wants to merge 2 commits intophp:masterfrom
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[Windows] allow clang to build tailcall vm, use __preserve_none for Call VM if available with msvc#21563henderkes wants to merge 2 commits intophp:masterfrom
henderkes wants to merge 2 commits intophp:masterfrom
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Not the largest improvement (~5-8% in my testing), but msvc's __preserve_none is not stable enough to use the tailcall vm with
[[msvc::musttail]].The tailcall VM for clang is a nice 25-30% improvement, but it still lags far behind msvc.
I'm not 100% sure if switching the call vm to __preserve_none could have any ill effects - Edit: forgot about the JIT... will take a while to track that down. If it's even feasible, I've never looked at the jit code.
PS: removing
/GUARD:CF(fromPHP_SECURITY_FLAGS) gives a 40% performance uplift in phoronix phpbench. I'm guessing disabling that isn't a good idea?