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author | Joseph Myers <joseph@codesourcery.com> | 2015-06-23 22:24:20 +0000 |
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committer | Joseph Myers <joseph@codesourcery.com> | 2015-06-23 22:24:20 +0000 |
commit | ad39cce0da0161dba69781c53349acf2e23f156c (patch) | |
tree | 1c7b29a8fe9358aa720485ca439db53d6749b379 /sysdeps/ieee754/ldbl-128ibm | |
parent | 8b1bab5ffa235bc494c33fdbe4c9994202936cfc (diff) | |
download | glibc-ad39cce0da0161dba69781c53349acf2e23f156c.tar.gz glibc-ad39cce0da0161dba69781c53349acf2e23f156c.tar.xz glibc-ad39cce0da0161dba69781c53349acf2e23f156c.zip |
Fix sin, sincos missing underflows (bug 16526, bug 16538).
Similar to various other bugs in this area, some sin and sincos 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 #16526] [BZ #16538] * sysdeps/ieee754/dbl-64/s_sin.c: Include <float.h>. (__sin): Force underflow exception for arguments with small absolute value. * sysdeps/ieee754/flt-32/k_sinf.c: Include <float.h>. (__kernel_sinf): Force underflow exception for arguments with small absolute value. * sysdeps/ieee754/ldbl-128/k_sincosl.c: Include <float.h>. (__kernel_sincosl): Force underflow exception for arguments with small absolute value. * sysdeps/ieee754/ldbl-128/k_sinl.c: Include <float.h>. (__kernel_sinl): Force underflow exception for arguments with small absolute value. * sysdeps/ieee754/ldbl-128ibm/k_sincosl.c: Include <float.h>. (__kernel_sincosl): Force underflow exception for arguments with small absolute value. * sysdeps/ieee754/ldbl-128ibm/k_sinl.c: Include <float.h>. (__kernel_sinl): Force underflow exception for arguments with small absolute value. * sysdeps/ieee754/ldbl-96/k_sinl.c: Include <float.h>. (__kernel_sinl): Force underflow exception for arguments with small absolute value. * sysdeps/powerpc/fpu/k_sinf.c: Include <float.h>. (__kernel_sinf): Force underflow exception for arguments with small absolute value. * math/auto-libm-test-in: Add more tests of sin and sincos. * math/auto-libm-test-out: Regenerated.
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm')
-rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/k_sincosl.c | 20 | ||||
-rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/k_sinl.c | 10 |
2 files changed, 23 insertions, 7 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c b/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c index f831e3f1f3..0a76e1c7e7 100644 --- a/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c +++ b/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c @@ -17,6 +17,7 @@ License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ +#include <float.h> #include <math.h> #include <math_private.h> @@ -112,12 +113,19 @@ __kernel_sincosl(long double x, long double y, long double *sinx, long double *c /* Argument is small enough to approximate it by a Chebyshev polynomial of degree 16(17). */ if (tix < 0x3c600000) /* |x| < 2^-57 */ - if (!((int)x)) /* generate inexact */ - { - *sinx = x; - *cosx = ONE; - return; - } + { + if (fabsl (x) < LDBL_MIN) + { + long double force_underflow = x * x; + math_force_eval (force_underflow); + } + if (!((int)x)) /* generate inexact */ + { + *sinx = x; + *cosx = ONE; + return; + } + } z = x * x; *sinx = x + (x * (z*(SIN1+z*(SIN2+z*(SIN3+z*(SIN4+ z*(SIN5+z*(SIN6+z*(SIN7+z*SIN8))))))))); diff --git a/sysdeps/ieee754/ldbl-128ibm/k_sinl.c b/sysdeps/ieee754/ldbl-128ibm/k_sinl.c index d6602fe365..2050cd2b49 100644 --- a/sysdeps/ieee754/ldbl-128ibm/k_sinl.c +++ b/sysdeps/ieee754/ldbl-128ibm/k_sinl.c @@ -17,6 +17,7 @@ License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ +#include <float.h> #include <math.h> #include <math_private.h> @@ -93,7 +94,14 @@ __kernel_sinl(long double x, long double y, int iy) /* Argument is small enough to approximate it by a Chebyshev polynomial of degree 17. */ if (tix < 0x3c600000) /* |x| < 2^-57 */ - if (!((int)x)) return x; /* generate inexact */ + { + if (fabsl (x) < LDBL_MIN) + { + long double force_underflow = x * x; + math_force_eval (force_underflow); + } + if (!((int)x)) return x; /* generate inexact */ + } z = x * x; return x + (x * (z*(SIN1+z*(SIN2+z*(SIN3+z*(SIN4+ z*(SIN5+z*(SIN6+z*(SIN7+z*SIN8))))))))); |