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authorJoseph Myers <joseph@codesourcery.com>2015-06-23 22:24:20 +0000
committerJoseph Myers <joseph@codesourcery.com>2015-06-23 22:24:20 +0000
commitad39cce0da0161dba69781c53349acf2e23f156c (patch)
tree1c7b29a8fe9358aa720485ca439db53d6749b379 /sysdeps/ieee754/ldbl-96/k_sinl.c
parent8b1bab5ffa235bc494c33fdbe4c9994202936cfc (diff)
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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-96/k_sinl.c')
-rw-r--r--sysdeps/ieee754/ldbl-96/k_sinl.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/sysdeps/ieee754/ldbl-96/k_sinl.c b/sysdeps/ieee754/ldbl-96/k_sinl.c
index 179262a735..b7b5ae359d 100644
--- a/sysdeps/ieee754/ldbl-96/k_sinl.c
+++ b/sysdeps/ieee754/ldbl-96/k_sinl.c
@@ -20,6 +20,7 @@
 /* The polynomials have not been optimized for extended-precision and
    may contain more terms than needed.  */
 
+#include <float.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -94,7 +95,14 @@ __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 (absx < 0x1p-33L)
-	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)))))))));