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| author | Joseph Myers <joseph@codesourcery.com> | 2015-04-08 17:14:12 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2015-04-08 17:14:12 +0000 |
| commit | ae63c7ebedcaa57017df4cb8ff0494a4705321ee (patch) | |
| tree | 4f2b413430bffe2a9c5354c5bd4e731106d7b832 /sysdeps | |
| parent | d5856d06c3ef62907f2865c502ada4baf3c9efa1 (diff) | |
| download | glibc-ae63c7ebedcaa57017df4cb8ff0494a4705321ee.tar glibc-ae63c7ebedcaa57017df4cb8ff0494a4705321ee.tar.gz glibc-ae63c7ebedcaa57017df4cb8ff0494a4705321ee.tar.bz2 glibc-ae63c7ebedcaa57017df4cb8ff0494a4705321ee.zip | |
Fix dbl-64 atan in non-default rounding modes (bug 18197).
The dbl-64 implementation of atan does computations that expect to run
in round-to-nearest mode, and in other modes the errors can accumulate
to more than the maximum accepted 9ulp. This patch makes it use
FE_TONEAREST internally, similar to other functions with such issues.
Tested for x86_64 and x86; no ulps updates needed.
[BZ #18197]
* sysdeps/ieee754/dbl-64/s_atan.c: Include <fenv.h>.
(atan): Set FE_TONEAREST mode for internal computations.
* math/auto-libm-test-in: Add more tests of atan.
* math/auto-libm-test-out: Regenerated.
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/s_atan.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/sysdeps/ieee754/dbl-64/s_atan.c b/sysdeps/ieee754/dbl-64/s_atan.c index 7b598f14a9..5035ae87bc 100644 --- a/sysdeps/ieee754/dbl-64/s_atan.c +++ b/sysdeps/ieee754/dbl-64/s_atan.c @@ -41,6 +41,7 @@ #include "MathLib.h" #include "uatan.tbl" #include "atnat.h" +#include <fenv.h> #include <float.h> #include <math.h> #include <math_private.h> @@ -81,6 +82,7 @@ atan (double x) return x + x; /* Regular values of x, including denormals +-0 and +-INF */ + SET_RESTORE_ROUND (FE_TONEAREST); u = (x < 0) ? -x : x; if (u < C) { |