From 6c9678ebd42358f931100130a368fafe375a0ba2 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Tue, 6 Oct 2015 17:37:49 +0000 Subject: Fix ldbl-128ibm expl overflow in non-default rounding modes (bug 19078). The ldbl-128ibm expl wrapper checks the argument to determine when to call __kernel_standard_l, thereby overriding overflowing results from __ieee754_expl that could otherwise (given appropriately patched libgcc) be correct for the rounding mode. This patch changes it to check the result of __ieee754_expl instead, as other versions of this wrapper do. Tested for powerpc. [BZ #19078] * sysdeps/ieee754/ldbl-128ibm/w_expl.c (o_thres): Remove variable. (u_thres): Likewise. (__expl): Determine whether to call __kernel_standard_l based on value of result, not argument. --- ChangeLog | 6 ++++++ NEWS | 2 +- sysdeps/ieee754/ldbl-128ibm/w_expl.c | 7 ++----- 3 files changed, 9 insertions(+), 6 deletions(-) diff --git a/ChangeLog b/ChangeLog index 2752bd2323..9b762b3a0c 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,11 @@ 2015-10-06 Joseph Myers + [BZ #19078] + * sysdeps/ieee754/ldbl-128ibm/w_expl.c (o_thres): Remove variable. + (u_thres): Likewise. + (__expl): Determine whether to call __kernel_standard_l based on + value of result, not argument. + * math/libm-test.inc (scalb_test_data): Add more expectations for the "inexact" exception. diff --git a/NEWS b/NEWS index e3c0795fe5..5ad75a32fd 100644 --- a/NEWS +++ b/NEWS @@ -18,7 +18,7 @@ Version 2.23 18820, 18823, 18824, 18825, 18857, 18863, 18870, 18872, 18873, 18875, 18887, 18921, 18951, 18952, 18956, 18961, 18966, 18967, 18969, 18970, 18977, 18980, 18981, 18985, 19003, 19012, 19016, 19018, 19032, 19046, - 19049, 19050, 19059, 19071, 19076, 19077. + 19049, 19050, 19059, 19071, 19076, 19077, 19078. * The obsolete header has been removed. Programs that require this header must be updated to use instead. diff --git a/sysdeps/ieee754/ldbl-128ibm/w_expl.c b/sysdeps/ieee754/ldbl-128ibm/w_expl.c index fb5c8d3629..c9d44b61dd 100644 --- a/sysdeps/ieee754/ldbl-128ibm/w_expl.c +++ b/sysdeps/ieee754/ldbl-128ibm/w_expl.c @@ -2,9 +2,6 @@ #include #include -static const long double o_thres = 709.78271289338399678773454114191496482L; -static const long double u_thres = -744.44007192138126231410729844608163411L; - long double __expl(long double x) /* wrapper exp */ { long double z; @@ -13,9 +10,9 @@ long double __expl(long double x) /* wrapper exp */ return z; if (isfinite(x)) { - if (x >= o_thres) + if (!isfinite (z)) return __kernel_standard_l(x,x,206); /* exp overflow */ - else if (x <= u_thres) + else if (z == 0.0L) return __kernel_standard_l(x,x,207); /* exp underflow */ } return z; -- cgit 1.4.1