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Commit8a934d6

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Use isinf builtin for clang, for performance.
When compiling with clang glibc's definition of isinf() ends upleading to and external libc function call. That's because there was abug in the builtin in an old gcc version, and clang claimscompatibility with an older version. That causes clang to bemeasurably slower for floating point heavy workloads than gcc.To fix simply redirect isinf when using clang and clang confirms ithas __builtin_isinf().
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‎src/include/port.h

Lines changed: 14 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -343,7 +343,20 @@ extern intgetpeereid(int sock, uid_t *uid, gid_t *gid);
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#ifndefHAVE_ISINF
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externintisinf(doublex);
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#endif
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#else
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/*
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* Glibc doesn't use the builtin for clang due to a *gcc* bug in a version
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* newer than the gcc compatibility clang claims to have. This would cause a
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* *lot* of superflous function calls, therefore revert when using clang.
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*/
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#ifdef__clang__
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/* needs to be separate to not confuse other compilers */
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#if__has_builtin(__builtin_isinf)
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#undef isinf
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#defineisinf __builtin_isinf
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#endif/* __has_builtin(isinf) */
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#endif/* __clang__ */
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#endif/* !HAVE_ISINF */
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#ifndefHAVE_MKDTEMP
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externchar*mkdtemp(char*path);

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