From 9a71f1fcf53615c00b5f9e5da4bba92bccb0efb4 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Thu, 14 May 2015 23:51:09 +0000 Subject: Fix atanf spurious underflows (bug 18196). The sysdeps/ieee754/flt-32 version of atanf produces spurious underflow exceptions for some large arguments, because of computations that compute x^-4. This patch fixes this by adjusting the threshold for large arguments (for which +/- pi/2 can just be returned, the correct result being roughly +/- pi/2 - 1/x) from 2^34 to 2^25. Tested for x86_64 and x86. [BZ #18196] * sysdeps/ieee754/flt-32/s_atanf.c (__atanf): Use 2^25 not 2^34 as threshold for large arguments. * math/auto-libm-test-in: Add another test of atan. * math/auto-libm-test-out: Regenerated. --- math/auto-libm-test-in | 1 + 1 file changed, 1 insertion(+) (limited to 'math/auto-libm-test-in') diff --git a/math/auto-libm-test-in b/math/auto-libm-test-in index 7e5c7bb..1deb99a 100644 --- a/math/auto-libm-test-in +++ b/math/auto-libm-test-in @@ -239,6 +239,7 @@ atan 0x1p-5 atan 2.5 atan 10 atan 1e6 +atan 0x1p31 atan 0x1p-100 atan 0x1p-600 atan 0x1p-10000 -- cgit v1.1