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| author | Dimitry Andric <dim@FreeBSD.org> | 2021-02-10 22:28:43 +0000 |
|---|---|---|
| committer | Dimitry Andric <dim@FreeBSD.org> | 2021-02-18 18:08:27 +0000 |
| commit | 97232b0dc03146c0e6466a4886edaaca4f95c3a7 (patch) | |
| tree | 02a4f16abc1f37f7d98b5b990eb66aa6151cc931 | |
| parent | c558999977fb759a64eede4cca96bee71a6a77d4 (diff) | |
| download | src-97232b0dc03146c0e6466a4886edaaca4f95c3a7.tar.gz src-97232b0dc03146c0e6466a4886edaaca4f95c3a7.zip | |
Fix incorrect hypotl(3) result with subnormal numbers
This adjusts the factor used to scale the subnormal numbers, so it
becomes the right value after adjusting its exponent. Thanks to Steve
Kargl for finding the most elegant fix.
Also enable the hypot tests, and add a test case for this bug.
PR: 253313
(cherry picked from commit d3338f3355a612cf385632291f46c5777bba8d18)
Fix lib/msun/test builds on platforms without 80-bit long doubles
After d3338f3355a612cf385632291f46c5777bba8d18, the lib/msun test case
'hypotl_near_underflow' would fail to compile on platforms where long
doubles weren't 80 bit, like on x86. Disable this particular test on
such platforms for now.
PR: 253313
(cherry picked from commit 25120662284466ecef976df8f86e97bafdedf991)
| -rw-r--r-- | contrib/netbsd-tests/lib/libm/t_hypot.c | 24 | ||||
| -rw-r--r-- | lib/msun/src/e_hypotl.c | 2 | ||||
| -rw-r--r-- | lib/msun/tests/Makefile | 1 |
3 files changed, 26 insertions, 1 deletions
diff --git a/contrib/netbsd-tests/lib/libm/t_hypot.c b/contrib/netbsd-tests/lib/libm/t_hypot.c index deb7e86ad5ac..cbb056ee470e 100644 --- a/contrib/netbsd-tests/lib/libm/t_hypot.c +++ b/contrib/netbsd-tests/lib/libm/t_hypot.c @@ -70,12 +70,36 @@ ATF_TC_BODY(pr50698, tc) ATF_CHECK(!isnan(val)); } +#if __LDBL_MANT_DIG__ == 64 +ATF_TC(hypotl_near_underflow); +ATF_TC_HEAD(hypotl_near_underflow, tc) +{ + atf_tc_set_md_var(tc, "descr", "Test hypotl near underflow"); +} + +ATF_TC_BODY(hypotl_near_underflow, tc) +{ + volatile long double a = 0x1.b2933cafa0bb7p-16383L; + volatile long double b = 0x1.fffffffffffffp-16351L; + volatile long double e = 0x1.fffffffffffffp-16351L; + volatile long double ulp = __LDBL_EPSILON__; + + volatile long double val = hypotl(a, b); + + ATF_CHECK(!isinf(val)); + ATF_CHECK(fabsl(val - e) <= 2 * ulp); +} +#endif /* __LDBL_MANT_DIG__ == 64 */ + ATF_TP_ADD_TCS(tp) { ATF_TP_ADD_TC(tp, hypot_integer); ATF_TP_ADD_TC(tp, hypotf_integer); ATF_TP_ADD_TC(tp, pr50698); +#if __LDBL_MANT_DIG__ == 64 + ATF_TP_ADD_TC(tp, hypotl_near_underflow); +#endif /* __LDBL_MANT_DIG__ == 64 */ return atf_no_error(); } diff --git a/lib/msun/src/e_hypotl.c b/lib/msun/src/e_hypotl.c index 9189b1fab54d..fc43538dfa65 100644 --- a/lib/msun/src/e_hypotl.c +++ b/lib/msun/src/e_hypotl.c @@ -82,7 +82,7 @@ hypotl(long double x, long double y) man_t manh, manl; GET_LDBL_MAN(manh,manl,b); if((manh|manl)==0) return a; - t1=0; + t1=1; SET_HIGH_WORD(t1,ESW(MAX_EXP-2)); /* t1=2^(MAX_EXP-2) */ b *= t1; a *= t1; diff --git a/lib/msun/tests/Makefile b/lib/msun/tests/Makefile index 5e9c54189bb7..67a38855309e 100644 --- a/lib/msun/tests/Makefile +++ b/lib/msun/tests/Makefile @@ -31,6 +31,7 @@ NETBSD_ATF_TESTS_C+= erf_test NETBSD_ATF_TESTS_C+= exp_test NETBSD_ATF_TESTS_C+= fmod_test NETBSD_ATF_TESTS_C+= fe_round_test +NETBSD_ATF_TESTS_C+= hypot_test NETBSD_ATF_TESTS_C+= infinity_test NETBSD_ATF_TESTS_C+= ilogb_test NETBSD_ATF_TESTS_C+= ldexp_test |