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| author | Joseph Myers <joseph@codesourcery.com> | 2015-08-07 23:10:35 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2015-08-07 23:10:35 +0000 |
| commit | 37550cb3d6591a8f443467707ec80b4ab5c2e157 (patch) | |
| tree | 934ef1da0ab3a2cd9d0a23b1645392914e95afcc /sysdeps/ieee754/ldbl-128ibm | |
| parent | db2bcbcb631f1c1aa023ef9f23a968e1ac288423 (diff) | |
| download | glibc-37550cb3d6591a8f443467707ec80b4ab5c2e157.tar.gz | |
Fix tan missing underflows (bug 16517).
Similar to various other bugs in this area, some tan implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #16517]
* sysdeps/ieee754/dbl-64/s_tan.c: Include <float.h>.
(tan): Force underflow exception for arguments with small absolute
value.
* sysdeps/ieee754/flt-32/k_tanf.c: Include <float.h>.
(__kernel_tanf): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128/k_tanl.c: Include <float.h>.
(__kernel_tanl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128ibm/k_tanl.c: Include <float.h>.
(__kernel_tanl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-96/k_tanl.c: Include <float.h>.
(__kernel_tanl): Force underflow exception for arguments with
small absolute value.
* math/auto-libm-test-in: Add more tests of tan.
* math/auto-libm-test-out: Regenerated.
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/k_tanl.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/k_tanl.c b/sysdeps/ieee754/ldbl-128ibm/k_tanl.c index 7f1caeebdf..e50cc88da4 100644 --- a/sysdeps/ieee754/ldbl-128ibm/k_tanl.c +++ b/sysdeps/ieee754/ldbl-128ibm/k_tanl.c @@ -56,6 +56,7 @@ * = 1 - 2*(tan(y) - (tan(y)^2)/(1+tan(y))) */ +#include <float.h> #include <libc-internal.h> #include <math.h> #include <math_private.h> @@ -98,8 +99,17 @@ __kernel_tanl (long double x, long double y, int iy) { if ((ix | lx | (iy + 1)) == 0) return one / fabs (x); + else if (iy == 1) + { + if (fabsl (x) < LDBL_MIN) + { + long double force_underflow = x * x; + math_force_eval (force_underflow); + } + return x; + } else - return (iy == 1) ? x : -one / x; + return -one / x; } } if (ix >= 0x3fe59420) /* |x| >= 0.6743316650390625 */ |