From 7d0b2575416aec2717e8665287d0ab77826a0ade Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Tue, 28 Apr 2015 17:27:02 +0000 Subject: Fix ldbl-128 roundl for exponents in [31, 47] (bug 18346). The implementation of roundl for ldbl-128 involves undefined behavior for arguments with exponents from 31 to 47 inclusive, from the shift: u_int64_t i = -1ULL >> (j0 - 48); For example, on mips64, this means roundl (0xffffffffffff.8p0L) wrongly returns its argument, which is not an integer. A condition checking for exponents < 31 should actually be checking for exponents < 48, and this patch makes it do so. (That condition is for whether the bit representing 0.5 is in the high 64-bit half of the floating-point number. The value 31 might have arisen from an incorrect conversion of the ldbl-96 version to handle ldbl-128.) This was originally reported as a GCC libquadmath bug . Tested for mips64; also tested for x86_64 and x86 to make sure the new tests pass there. [BZ #18346] * sysdeps/ieee754/ldbl-128/s_roundl.c (__roundl): Handle all exponents less than 48 as cases where high part of mantissa needs examining to determine whether argument is integral. * math/libm-test.inc (round_test_data): Add more tests. --- NEWS | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'NEWS') diff --git a/NEWS b/NEWS index 72e15f523f..fc3911dc29 100644 --- a/NEWS +++ b/NEWS @@ -16,7 +16,7 @@ Version 2.22 17967, 17969, 17978, 17987, 17991, 17996, 17998, 17999, 18019, 18020, 18029, 18030, 18032, 18036, 18038, 18039, 18042, 18043, 18046, 18047, 18068, 18080, 18093, 18100, 18104, 18110, 18111, 18128, 18138, 18185, - 18197, 18206, 18210, 18211, 18247, 18287, 18333. + 18197, 18206, 18210, 18211, 18247, 18287, 18333, 18346. * Cache information can be queried via sysconf() function on s390 e.g. with _SC_LEVEL1_ICACHE_SIZE as argument. -- cgit 1.4.1