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| author | Victor Stinner <victor.stinner@haypocalc.com> | 2011-05-09 10:45:41 (GMT) |
|---|---|---|
| committer | Victor Stinner <victor.stinner@haypocalc.com> | 2011-05-09 10:45:41 (GMT) |
| commit | 8f9f8d612a1ee264a465f493b1ce6215418128de (patch) | |
| tree | 932bbe3ba95806fc499f853fe25c2ec3726c6afa /Modules/mathmodule.c | |
| parent | 936d518dc8fb8fb094de1391d5a0703287db694e (diff) | |
| download | cpython-8f9f8d612a1ee264a465f493b1ce6215418128de.zip cpython-8f9f8d612a1ee264a465f493b1ce6215418128de.tar.gz cpython-8f9f8d612a1ee264a465f493b1ce6215418128de.tar.bz2 | |
Issue #11888: Use system log2() when available
I expect the system libc to use more accurate functions than Python. The GNU
libc uses for example FYL2X and FYL2XP1 hardware instructions on Intel FPU.
Diffstat (limited to 'Modules/mathmodule.c')
| -rw-r--r-- | Modules/mathmodule.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c index 14d008a..cebb4ff 100644 --- a/Modules/mathmodule.c +++ b/Modules/mathmodule.c @@ -602,6 +602,9 @@ m_log2(double x) } if (x > 0.0) { +#ifdef HAVE_LOG2 + return log2(x); +#else double m; int e; m = frexp(x, &e); @@ -617,6 +620,7 @@ m_log2(double x) else { return log(m) / log(2.0) + e; } +#endif } else if (x == 0.0) { errno = EDOM; |