Set errno for atan2 underflow (bug 16349)
Commit Message
This patch fixes bug 16349, missing errno setting for atan2 underflow,
by adding appropriate checks to the existing wrappers. (As in other
cases, the __kernel_standard support for calling matherr is considered
to be for existing code expecting existing rules for what's considered
an error, even if those don't correspond to a general logical scheme
for what counts as what kind of error, so __set_errno calls are added
directly without any changes to __kernel_standard.)
Tested x86_64 and x86.
(auto-libm-test-out diffs omitted below.)
2014-03-25 Joseph Myers <joseph@codesourcery.com>
[BZ #16349]
* math/w_atan2.c: Include <errno.h>.
(__atan2): Set errno for result underflowing to zero.
* math/w_atan2f.c: Include <errno.h>.
(__atan2f): Set errno for result underflowing to zero.
* math/w_atan2l.c: Include <errno.h>.
(__atan2l): Set errno for result underflowing to zero.
* math/auto-libm-test-in: Don't allow missing errno for some atan2
tests.
* math/auto-libm-test-out: Regenerated.
Comments
Ping. This patch
<https://sourceware.org/ml/libc-alpha/2014-03/msg00786.html> is pending
review.
On 03/25/2014 05:07 PM, Joseph S. Myers wrote:
> This patch fixes bug 16349, missing errno setting for atan2 underflow,
> by adding appropriate checks to the existing wrappers. (As in other
> cases, the __kernel_standard support for calling matherr is considered
> to be for existing code expecting existing rules for what's considered
> an error, even if those don't correspond to a general logical scheme
> for what counts as what kind of error, so __set_errno calls are added
> directly without any changes to __kernel_standard.)
>
> Tested x86_64 and x86.
>
> (auto-libm-test-out diffs omitted below.)
>
> 2014-03-25 Joseph Myers <joseph@codesourcery.com>
>
> [BZ #16349]
> * math/w_atan2.c: Include <errno.h>.
> (__atan2): Set errno for result underflowing to zero.
> * math/w_atan2f.c: Include <errno.h>.
> (__atan2f): Set errno for result underflowing to zero.
> * math/w_atan2l.c: Include <errno.h>.
> (__atan2l): Set errno for result underflowing to zero.
> * math/auto-libm-test-in: Don't allow missing errno for some atan2
> tests.
> * math/auto-libm-test-out: Regenerated.
ok, thanks,
Andreas
@@ -157,13 +157,12 @@ atan2 -min -max
atan2 min_subnorm -max
atan2 -min_subnorm -max
# Bug 15319: underflow exception may be missing.
-# Bug 16349: errno setting may be missing.
atan2 1 max missing-underflow
atan2 -1 max missing-underflow
-atan2 min max missing-underflow missing-errno
-atan2 -min max missing-underflow missing-errno
-atan2 min_subnorm max missing-underflow missing-errno
-atan2 -min_subnorm max missing-underflow missing-errno
+atan2 min max missing-underflow
+atan2 -min max missing-underflow
+atan2 min_subnorm max missing-underflow
+atan2 -min_subnorm max missing-underflow
atanh 0
atanh -0
@@ -20,6 +20,7 @@
* wrapper atan2(y,x)
*/
+#include <errno.h>
#include <math.h>
#include <math_private.h>
@@ -27,10 +28,15 @@
double
__atan2 (double y, double x)
{
+ double z;
+
if (__builtin_expect (x == 0.0 && y == 0.0, 0) && _LIB_VERSION == _SVID_)
return __kernel_standard (y, x, 3); /* atan2(+-0,+-0) */
- return __ieee754_atan2 (y, x);
+ z = __ieee754_atan2 (y, x);
+ if (__glibc_unlikely (z == 0.0 && y != 0.0 && __finite (x)))
+ __set_errno (ERANGE);
+ return z;
}
weak_alias (__atan2, atan2)
#ifdef NO_LONG_DOUBLE
@@ -20,6 +20,7 @@
* wrapper atan2f(y,x)
*/
+#include <errno.h>
#include <math.h>
#include <math_private.h>
@@ -27,9 +28,14 @@
float
__atan2f (float y, float x)
{
+ float z;
+
if (__builtin_expect (x == 0.0f && y == 0.0f, 0) && _LIB_VERSION == _SVID_)
return __kernel_standard_f (y, x, 103); /* atan2(+-0,+-0) */
- return __ieee754_atan2f (y, x);
+ z = __ieee754_atan2f (y, x);
+ if (__glibc_unlikely (z == 0.0f && y != 0.0f && __finitef (x)))
+ __set_errno (ERANGE);
+ return z;
}
weak_alias (__atan2f, atan2f)
@@ -20,6 +20,7 @@
* wrapper atan2l(y,x)
*/
+#include <errno.h>
#include <math.h>
#include <math_private.h>
@@ -27,9 +28,14 @@
long double
__atan2l (long double y, long double x)
{
+ long double z;
+
if (__builtin_expect (x == 0.0L && y == 0.0L, 0) && _LIB_VERSION == _SVID_)
return __kernel_standard_l (y, x, 203); /* atan2(+-0,+-0) */
- return __ieee754_atan2l (y, x);
+ z = __ieee754_atan2l (y, x);
+ if (__glibc_unlikely (z == 0.0L && y != 0.0L && __finitel (x)))
+ __set_errno (ERANGE);
+ return z;
}
weak_alias (__atan2l, atan2l)