From 8db3cdefefe39e9d42b05b1610a63190e9f7fba4 Mon Sep 17 00:00:00 2001
From: Joseph Myers <joseph@codesourcery.com>
Date: Thu, 18 Jun 2015 23:27:41 +0000
Subject: Fix asinh missing underflows (bug 16350).

Similar to various other bugs in this area, some asinh 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 and mips64.

	[BZ #16350]
	* sysdeps/i386/fpu/s_asinh.S (__asinh): Force underflow exception
	for arguments with small absolute value.
	* sysdeps/i386/fpu/s_asinhf.S (__asinhf): Likewise.
	* sysdeps/i386/fpu/s_asinhl.S (__asinhl): Likewise.
	* sysdeps/ieee754/dbl-64/s_asinh.c: Include <float.h>.
	(__asinh): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/flt-32/s_asinhf.c: Include <float.h>.
	(__asinhf): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/ldbl-128/s_asinhl.c: Include <float.h>.
	(__asinhl): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/ldbl-128ibm/s_asinhl.c: Include <float.h>.
	(__asinhl): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/ldbl-96/s_asinhl.c: Include <float.h>.
	(__asinhl): Force underflow exception for arguments with small
	absolute value.
	* math/auto-libm-test-in: Do not mark underflow exceptions as
	possibly missing for bug 16350.
	* math/auto-libm-test-out: Regenerated.
---
 sysdeps/ieee754/dbl-64/s_asinh.c | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'sysdeps/ieee754/dbl-64')

diff --git a/sysdeps/ieee754/dbl-64/s_asinh.c b/sysdeps/ieee754/dbl-64/s_asinh.c
index a33758d3c9..ebe471015b 100644
--- a/sysdeps/ieee754/dbl-64/s_asinh.c
+++ b/sysdeps/ieee754/dbl-64/s_asinh.c
@@ -21,6 +21,7 @@
  *		 := sign(x)*log1p(|x| + x^2/(1 + sqrt(1+x^2)))
  */
 
+#include <float.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -38,6 +39,11 @@ __asinh (double x)
   ix = hx & 0x7fffffff;
   if (__glibc_unlikely (ix < 0x3e300000))                  /* |x|<2**-28 */
     {
+      if (fabs (x) < DBL_MIN)
+	{
+	  double force_underflow = x * x;
+	  math_force_eval (force_underflow);
+	}
       if (huge + x > one)
 	return x;                       /* return x inexact except 0 */
     }
-- 
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