bpo-37774: use Py_LIKELY/Py_UNLIKELY for vectorcall #15144
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Include/pymacro.h
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I think __GNUC__ > 2 is redundant.
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Redundant because Python won't compile with GCC 2.x anyway?
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Because:
- I don't know GCC 2.x supports all of C99 features we use in PEP 7.
- I don't know how to use GCC 2 to compile Python in recent days.
- I don't know who try to compile Python with GCC 2.
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I found this page: https://gcc.gnu.org/c99status.html
We use some GCC>=3.0 features already.
- designated initializers
- new block scopes for selection and iteration statements
- stdbool.h (GCC 2.95 had
<stdbool.h>, but based on an early draft with major differences from C99 semantics.)
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I don't think these macros are useful for PGO build. In case of obmalloc.c, it only affects non-PGO build. |
jdemeyer
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Rebased to latest master, fixed conflicts in @markshannon: what's your opinion on this? It achieves the same speedup as #14735 but in a more structural way. |
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@markshannon do you have time for a review of this PR? Thank you |
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This has three approvals - should it be merged once the conflicts are resolved? |
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As @methane has said, given PGO does this for us, what's the point? Having said that. I'd be OK with https://github.com/python/cpython/pull/15144/files#diff-7f17c8d8448b7b6f90549035d2147a9fR4978 being added, as performance is deliberately being sacrificed when As for the others, probably not. |
markshannon
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markshannon
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I see no benefit to this.
I'd rather leave this sort of tweaking to tools as they can adapt as the surrounding code changes.
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@jdemeyer do you mind if I close this? |
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This is rather out of date now, so I'm closing it. |
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Closing as there are conflicts and the benefit is unclear. |
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CC @markshannon @methane
https://bugs.python.org/issue37774