From 8e27e3cc453849158e069dbed0eea7b8113ab8ff Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Thu, 22 Nov 2012 14:57:22 +0000 Subject: Fix ldbl-128ibm hypotl inaccuracy for arguments with large ratio (bug 14868). --- ChangeLog | 5 +++++ NEWS | 2 +- math/libm-test.inc | 2 ++ sysdeps/ieee754/ldbl-128ibm/e_hypotl.c | 2 +- 4 files changed, 9 insertions(+), 2 deletions(-) diff --git a/ChangeLog b/ChangeLog index c2421fa..69dd8fe 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,10 @@ 2012-11-22 Joseph Myers + [BZ #14868] + * sysdeps/ieee754/ldbl-128ibm/e_hypotl.c (__ieee754_hypotl): + Return a+b for ratio over 2**120, not 2**60. + * math/libm-test.inc (hypot_test): Add another test. + * math/libm-test.inc (clog_test): Use UNDERFLOW_EXCEPTION_LDOUBLE_IBM on two tests. (clog10_test): Likewise. diff --git a/NEWS b/NEWS index c17a557..94e1260 100644 --- a/NEWS +++ b/NEWS @@ -21,7 +21,7 @@ Version 2.17 14638, 14645, 14648, 14652, 14660, 14661, 14669, 14672, 14683, 14694, 14716, 14719, 14743, 14767, 14783, 14784, 14785, 14793, 14796, 14797, 14801, 14805, 14807, 14809, 14811, 14815, 14821, 14822, 14824, 14828, - 14831, 14835, 14838, 14856, 14863, 14865, 14866. + 14831, 14835, 14838, 14856, 14863, 14865, 14866, 14868. * Port to ARM AArch64 contributed by Linaro. diff --git a/math/libm-test.inc b/math/libm-test.inc index 74ef15b..21f4646 100644 --- a/math/libm-test.inc +++ b/math/libm-test.inc @@ -5730,6 +5730,8 @@ hypot_test (void) TEST_ff_f (hypot, 0.75L, 1.25L, 1.45773797371132511771853821938639577L); + TEST_ff_f (hypot, 1.0L, 0x1p-61L, 1.0L); + #if !(defined TEST_FLOAT && defined TEST_INLINE) TEST_ff_f (hypot, 0x3p125L, 0x4p125L, 0x5p125L); TEST_ff_f (hypot, 0x1.234566p-126L, 0x1.234566p-126L, 1.891441686191081936598531534017449451173e-38L); diff --git a/sysdeps/ieee754/ldbl-128ibm/e_hypotl.c b/sysdeps/ieee754/ldbl-128ibm/e_hypotl.c index 00bfb15..ce21194 100644 --- a/sysdeps/ieee754/ldbl-128ibm/e_hypotl.c +++ b/sysdeps/ieee754/ldbl-128ibm/e_hypotl.c @@ -61,7 +61,7 @@ __ieee754_hypotl(long double x, long double y) if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;} a = fabsl(a); /* a <- |a| */ b = fabsl(b); /* b <- |b| */ - if((ha-hb)>0x3c0000000000000LL) {return a+b;} /* x/y > 2**60 */ + if((ha-hb)>0x780000000000000LL) {return a+b;} /* x/y > 2**120 */ k=0; kld = 1.0L; if(ha > 0x5f30000000000000LL) { /* a>2**500 */ -- cgit v1.1