Joseph Myers
1f4dafa3ea
Use C11 *_TRUE_MIN macros where applicable.
...
C11 defines standard <float.h> macros *_TRUE_MIN for the least
positive subnormal value of a type. Now that we build with
-std=gnu11, we can use these macros in glibc. This patch replaces
previous uses of the GCC predefines __*_DENORM_MIN__ (used in
<float.h> to define *_TRUE_MIN), as well as *_DENORM_MIN references in
comments.
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch). Also tested for powerpc that
installed stripped shared libraries are unchanged by the patch.
* math/libm-test.inc (min_subnorm_value): Use LDBL_TRUE_MIN,
DBL_TRUE_MIN and FLT_TRUE_MIN instead of __LDBL_DENORM_MIN__,
__DBL_DENORM_MIN__ and __FLT_DENORM_MIN__.
* sysdeps/ieee754/dbl-64/s_fma.c (__fma): Refer to DBL_TRUE_MIN
instead of DBL_DENORM_MIN in comment.
* sysdeps/ieee754/ldbl-128/s_fmal.c (__fmal): Refer to
LDBL_TRUE_MIN instead of LDBL_DENORM_MIN in comment.
* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c: Include <float.h>.
(__nextafterl): Use LDBL_TRUE_MIN instead of __LDBL_DENORM_MIN__.
* sysdeps/ieee754/ldbl-96/s_fmal.c (__fmal): Refer to
LDBL_TRUE_MIN instead of LDBL_DENORM_MIN in comment.
2015-10-28 21:42:52 +00:00
Joseph Myers
d96164c330
Refactor code forcing underflow exceptions.
...
Various floating-point functions have code to force underflow
exceptions if a tiny result was computed in a way that might not have
resulted in such exceptions even though the result is inexact. This
typically uses math_force_eval to ensure that the underflowing
expression is evaluated, but sometimes uses volatile.
This patch refactors such code to use three new macros
math_check_force_underflow, math_check_force_underflow_nonneg and
math_check_force_underflow_complex (which in turn use
math_force_eval). In the limited number of cases not suited to a
simple conversion to these macros, existing uses of volatile are
changed to use math_force_eval instead. The converted code does not
always execute exactly the same sequence of operations as the original
code, but the overall effects should be the same.
Tested for x86_64, x86, mips64 and powerpc.
* sysdeps/generic/math_private.h (fabs_tg): New macro.
(min_of_type): Likewise.
(math_check_force_underflow): Likewise.
(math_check_force_underflow_nonneg): Likewise.
(math_check_force_underflow_complex): Likewise.
* math/e_exp2l.c (__ieee754_exp2l): Use
math_check_force_underflow_nonneg.
* math/k_casinh.c (__kernel_casinh): Likewise.
* math/k_casinhf.c (__kernel_casinhf): Likewise.
* math/k_casinhl.c (__kernel_casinhl): Likewise.
* math/s_catan.c (__catan): Use
math_check_force_underflow_complex.
* math/s_catanf.c (__catanf): Likewise.
* math/s_catanh.c (__catanh): Likewise.
* math/s_catanhf.c (__catanhf): Likewise.
* math/s_catanhl.c (__catanhl): Likewise.
* math/s_catanl.c (__catanl): Likewise.
* math/s_ccosh.c (__ccosh): Likewise.
* math/s_ccoshf.c (__ccoshf): Likewise.
* math/s_ccoshl.c (__ccoshl): Likewise.
* math/s_cexp.c (__cexp): Likewise.
* math/s_cexpf.c (__cexpf): Likewise.
* math/s_cexpl.c (__cexpl): Likewise.
* math/s_clog.c (__clog): Use math_check_force_underflow_nonneg.
* math/s_clog10.c (__clog10): Likewise.
* math/s_clog10f.c (__clog10f): Likewise.
* math/s_clog10l.c (__clog10l): Likewise.
* math/s_clogf.c (__clogf): Likewise.
* math/s_clogl.c (__clogl): Likewise.
* math/s_csin.c (__csin): Use math_check_force_underflow_complex.
* math/s_csinf.c (__csinf): Likewise.
* math/s_csinh.c (__csinh): Likewise.
* math/s_csinhf.c (__csinhf): Likewise.
* math/s_csinhl.c (__csinhl): Likewise.
* math/s_csinl.c (__csinl): Likewise.
* math/s_csqrt.c (__csqrt): Use math_check_force_underflow.
* math/s_csqrtf.c (__csqrtf): Likewise.
* math/s_csqrtl.c (__csqrtl): Likewise.
* math/s_ctan.c (__ctan): Use math_check_force_underflow_complex.
* math/s_ctanf.c (__ctanf): Likewise.
* math/s_ctanh.c (__ctanh): Likewise.
* math/s_ctanhf.c (__ctanhf): Likewise.
* math/s_ctanhl.c (__ctanhl): Likewise.
* math/s_ctanl.c (__ctanl): Likewise.
* stdlib/strtod_l.c (round_and_return): Use math_force_eval
instead of volatile.
* sysdeps/ieee754/dbl-64/e_asin.c (__ieee754_asin): Use
math_check_force_underflow.
* sysdeps/ieee754/dbl-64/e_atanh.c (__ieee754_atanh): Likewise.
* sysdeps/ieee754/dbl-64/e_exp.c (__ieee754_exp): Do not use
volatile when forcing underflow.
* sysdeps/ieee754/dbl-64/e_exp2.c (__ieee754_exp2): Use
math_check_force_underflow_nonneg.
* sysdeps/ieee754/dbl-64/e_gamma_r.c (__ieee754_gamma_r):
Likewise.
* sysdeps/ieee754/dbl-64/e_j1.c (__ieee754_j1): Use
math_check_force_underflow.
* sysdeps/ieee754/dbl-64/e_jn.c (__ieee754_jn): Likewise.
* sysdeps/ieee754/dbl-64/e_sinh.c (__ieee754_sinh): Likewise.
* sysdeps/ieee754/dbl-64/s_asinh.c (__asinh): Likewise.
* sysdeps/ieee754/dbl-64/s_atan.c (atan): Use
math_check_force_underflow_nonneg.
* sysdeps/ieee754/dbl-64/s_erf.c (__erf): Use
math_check_force_underflow.
* sysdeps/ieee754/dbl-64/s_expm1.c (__expm1): Likewise.
* sysdeps/ieee754/dbl-64/s_fma.c (__fma): Use math_force_eval
instead of volatile.
* sysdeps/ieee754/dbl-64/s_log1p.c (__log1p): Use
math_check_force_underflow.
* sysdeps/ieee754/dbl-64/s_sin.c (__sin): Likewise.
* sysdeps/ieee754/dbl-64/s_tan.c (tan): Use
math_check_force_underflow_nonneg.
* sysdeps/ieee754/dbl-64/s_tanh.c (__tanh): Use
math_check_force_underflow.
* sysdeps/ieee754/flt-32/e_asinf.c (__ieee754_asinf): Likewise.
* sysdeps/ieee754/flt-32/e_atanhf.c (__ieee754_atanhf): Likewise.
* sysdeps/ieee754/flt-32/e_exp2f.c (__ieee754_exp2f): Use
math_check_force_underflow_nonneg.
* sysdeps/ieee754/flt-32/e_gammaf_r.c (__ieee754_gammaf_r):
Likewise.
* sysdeps/ieee754/flt-32/e_j1f.c (__ieee754_j1f): Use
math_check_force_underflow.
* sysdeps/ieee754/flt-32/e_jnf.c (__ieee754_jnf): Likewise.
* sysdeps/ieee754/flt-32/e_sinhf.c (__ieee754_sinhf): Likewise.
* sysdeps/ieee754/flt-32/k_sinf.c (__kernel_sinf): Likewise.
* sysdeps/ieee754/flt-32/k_tanf.c (__kernel_tanf): Likewise.
* sysdeps/ieee754/flt-32/s_asinhf.c (__asinhf): Likewise.
* sysdeps/ieee754/flt-32/s_atanf.c (__atanf): Likewise.
* sysdeps/ieee754/flt-32/s_erff.c (__erff): Likewise.
* sysdeps/ieee754/flt-32/s_expm1f.c (__expm1f): Likewise.
* sysdeps/ieee754/flt-32/s_log1pf.c (__log1pf): Likewise.
* sysdeps/ieee754/flt-32/s_tanhf.c (__tanhf): Likewise.
* sysdeps/ieee754/ldbl-128/e_asinl.c (__ieee754_asinl): Likewise.
* sysdeps/ieee754/ldbl-128/e_atanhl.c (__ieee754_atanhl):
Likewise.
* sysdeps/ieee754/ldbl-128/e_expl.c (__ieee754_expl): Use
math_check_force_underflow_nonneg.
* sysdeps/ieee754/ldbl-128/e_gammal_r.c (__ieee754_gammal_r):
Likewise.
* sysdeps/ieee754/ldbl-128/e_j1l.c (__ieee754_j1l): Use
math_check_force_underflow.
* sysdeps/ieee754/ldbl-128/e_jnl.c (__ieee754_jnl): Likewise.
* sysdeps/ieee754/ldbl-128/e_sinhl.c (__ieee754_sinhl): Likewise.
* sysdeps/ieee754/ldbl-128/k_sincosl.c (__kernel_sincosl):
Likewise.
* sysdeps/ieee754/ldbl-128/k_sinl.c (__kernel_sinl): Likewise.
* sysdeps/ieee754/ldbl-128/k_tanl.c (__kernel_tanl): Likewise.
* sysdeps/ieee754/ldbl-128/s_asinhl.c (__asinhl): Likewise.
* sysdeps/ieee754/ldbl-128/s_atanl.c (__atanl): Likewise.
* sysdeps/ieee754/ldbl-128/s_erfl.c (__erfl): Likewise.
* sysdeps/ieee754/ldbl-128/s_expm1l.c (__expm1l): Likewise.
* sysdeps/ieee754/ldbl-128/s_fmal.c (__fmal): Use math_force_eval
instead of volatile.
* sysdeps/ieee754/ldbl-128/s_log1pl.c (__log1pl): Use
math_check_force_underflow.
* sysdeps/ieee754/ldbl-128/s_tanhl.c (__tanhl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_asinl.c (__ieee754_asinl): Use
math_check_force_underflow.
* sysdeps/ieee754/ldbl-128ibm/e_atanhl.c (__ieee754_atanhl):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c (__ieee754_gammal_r):
Use math_check_force_underflow_nonneg.
* sysdeps/ieee754/ldbl-128ibm/e_jnl.c (__ieee754_jnl): Use
math_check_force_underflow.
* sysdeps/ieee754/ldbl-128ibm/e_sinhl.c (__ieee754_sinhl):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/k_sincosl.c (__kernel_sincosl):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/k_sinl.c (__kernel_sinl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/k_tanl.c (__kernel_tanl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_asinhl.c (__asinhl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_atanl.c (__atanl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_erfl.c (__erfl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_tanhl.c (__tanhl): Likewise.
* sysdeps/ieee754/ldbl-96/e_asinl.c (__ieee754_asinl): Likewise.
* sysdeps/ieee754/ldbl-96/e_atanhl.c (__ieee754_atanhl): Likewise.
* sysdeps/ieee754/ldbl-96/e_gammal_r.c (__ieee754_gammal_r): Use
math_check_force_underflow_nonneg.
* sysdeps/ieee754/ldbl-96/e_j1l.c (__ieee754_j1l): Use
math_check_force_underflow.
* sysdeps/ieee754/ldbl-96/e_jnl.c (__ieee754_jnl): Likewise.
* sysdeps/ieee754/ldbl-96/e_sinhl.c (__ieee754_sinhl): Likewise.
* sysdeps/ieee754/ldbl-96/k_sinl.c (__kernel_sinl): Likewise.
* sysdeps/ieee754/ldbl-96/k_tanl.c (__kernel_tanl): Use
math_check_force_underflow_nonneg.
* sysdeps/ieee754/ldbl-96/s_asinhl.c (__asinhl): Use
math_check_force_underflow.
* sysdeps/ieee754/ldbl-96/s_erfl.c (__erfl): Likewise.
* sysdeps/ieee754/ldbl-96/s_fmal.c (__fmal): Use math_force_eval
instead of volatile.
* sysdeps/ieee754/ldbl-96/s_tanhl.c (__tanhl): Use
math_check_force_underflow.
2015-09-23 22:42:30 +00:00
Joseph Myers
739babd775
Fix fma spurious underflows (bug 18824).
...
Various fma implementations have logic that, when computing fma (x, y,
z) where z is large (so care needs taking to avoid internal overflow)
but x * y is small, scale x * y up instead of down to avoid internal
underflows resulting from scaling down. (In these cases, x * y is
small enough that only its sign actually matters rather than the exact
value.)
The threshold for scaling up instead of down was correct for "if the
unscaled values were multiplied, the low part of the multiplication
could underflow", and the scaling was sufficient to ensure that the
low part of the multiplication did not underflow (given that cases of
very small x * y - less than half the least subnormal - were
previously dealt with). However, the choice in the functions wasn't
between scaling up or no scaling, but between scaling up and scaling
down (scaling down actually being needed when x * y isn't so small
compared to z and so the exact value does matter). Thus a larger
threshold is needed to ensure that scaling down doesn't produce values
the multiplication of whose low parts underflows. This patch
increases the thresholds accordingly.
Tested for x86_64, x86 and mips64 (with the MIPS version of s_fmal.c
removed so that the ldbl-128 version gets tested instead of the
soft-fp one).
[BZ #18824 ]
* sysdeps/ieee754/dbl-64/s_fma.c (__fma): Increase threshold for
scaling x * y up instead of down.
* sysdeps/ieee754/ldbl-128/s_fmal.c (__fmal): Likewise.
* sysdeps/ieee754/ldbl-96/s_fmal.c (__fmal): Likewise.
* math/auto-libm-test-in: Add more tests of fma.
* math/auto-libm-test-out: Regenerated.
2015-08-14 17:15:06 +00:00
Joseph Myers
b168057aaa
Update copyright dates with scripts/update-copyrights.
2015-01-02 16:29:47 +00:00
Richard Henderson
4896f04920
Force eval for fma implementations
2014-08-01 12:13:50 -10:00
Ondřej Bílka
a1ffb40e32
Use glibc_likely instead __builtin_expect.
2014-02-10 15:07:12 +01:00
Allan McRae
d4697bc93d
Update copyright notices with scripts/update-copyrights
2014-01-01 22:00:23 +10:00
Joseph Myers
568035b787
Update copyright notices with scripts/update-copyrights.
2013-01-02 19:05:09 +00:00
Joseph Myers
82477c28f4
Fix fma underflows with small x * y (bug 14793).
2012-11-06 14:12:54 +00:00
Joseph Myers
a0c2940d67
Fix fma overflow results outside round-to-nearest mode (bug 14797).
2012-11-04 19:26:02 +00:00
Joseph Myers
5b5b04d628
Make fma use of Dekker and Knuth algorithms use round-to-nearest (bug 14796).
2012-11-03 19:48:53 +00:00
Joseph Myers
473611b22d
Fix fma (a, b, c) for small a * b (bugs 14784, 14785).
2012-11-01 16:47:26 +00:00
Joseph Myers
ef82f4da79
Fix fma underflow exceptions in after-rounding edge cases.
2012-10-31 13:01:17 +00:00
Joseph Myers
8627a2329c
Fix fma missing underflows and bad results for some subnormal results (bugs 14152, 14783).
2012-10-30 13:54:50 +00:00
Joseph Myers
bec749fda1
Fix sign of inexact zero return from fma (bug 14645).
2012-10-01 08:30:06 +00:00
Joseph Myers
8ec5b01346
Fix sign of exact zero return from fma (bug 14638).
2012-09-29 18:31:54 +00:00
Aurelien Jarno
efb734887e
Add a barrier in the double fma implementation.
2012-06-01 19:01:17 +00:00
Richard Henderson
0fe0f1f86f
Create and use libc_feupdateenv_test.
...
We can reduce the number of STMXCSR, and often we can avoid the
call to __feraiseexcept.
2012-03-19 06:50:41 -07:00
Paul Eggert
59ba27a63a
Replace FSF snail mail address with URLs.
2012-02-09 23:18:22 +00:00
Ulrich Drepper
d9a8d0abcc
Use new internal libc_fe* interfaces in more functions
2011-10-18 15:11:31 -04:00
Jakub Jelinek
3e692e0518
Implement fmal, some fma bugfixes
2010-10-15 15:26:06 -04:00
Jakub Jelinek
f3f7372de1
Fix some more dbl-64/s_fma.c issue
2010-10-15 15:25:14 -04:00
Jakub Jelinek
5e908464b9
Implement accurate fma.
2010-10-13 22:27:03 -04:00