Commit Graph

7 Commits

Author SHA1 Message Date
Wilco Dijkstra
220622dde5 Add libm_alias_finite for _finite symbols
This patch adds a new macro, libm_alias_finite, to define all _finite
symbol.  It sets all _finite symbol as compat symbol based on its first
version (obtained from the definition at built generated first-versions.h).

The <fn>f128_finite symbols were introduced in GLIBC 2.26 and so need
special treatment in code that is shared between long double and float128.
It is done by adding a list, similar to internal symbol redifinition,
on sysdeps/ieee754/float128/float128_private.h.

Alpha also needs some tricky changes to ensure we still emit 2 compat
symbols for sqrt(f).

Passes buildmanyglibc.

Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2020-01-03 10:02:04 -03:00
Joseph Myers
aaee3cd88e Move math_narrow_eval to separate math-narrow-eval.h.
This patch continues cleaning up the math_private.h header, which
contains lots of different definitions many of which are only needed
by a limited subset of files using that header (and some of which are
overridden by architectures that only want to override selected parts
of the header), by moving the math_narrow_eval macro out to a separate
math-narrow-eval.h header, only included by those files that need it.
That header is placed in include/ (since it's used in stdlib/, not
just files built in math/, but no sysdeps variants are needed at
present).

Tested for x86_64, and with build-many-glibcs.py.  (Installed stripped
shared libraries change because of line numbers in assertions in
strtod_l.c.)

	* include/math-narrow-eval.h: New file.  Contents moved from ....
	* sysdeps/generic/math_private.h: ... here.
	(math_narrow_eval): Remove macro.  Moved to math-narrow-eval.h.
	[FLT_EVAL_METHOD != 0] (excess_precision): Likewise.
	* math/s_fdim_template.c: Include <math-narrow-eval.h>.
	* stdlib/strtod_l.c: Likewise.
	* sysdeps/i386/fpu/s_f32xaddf64.c: Likewise.
	* sysdeps/i386/fpu/s_f32xsubf64.c: Likewise.
	* sysdeps/i386/fpu/s_fdim.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_cosh.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_gamma_r.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_j1.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_jn.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_lgamma_r.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_sinh.c: Likewise.
	* sysdeps/ieee754/dbl-64/gamma_productf.c: Likewise.
	* sysdeps/ieee754/dbl-64/k_rem_pio2.c: Likewise.
	* sysdeps/ieee754/dbl-64/lgamma_neg.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_erf.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_llrint.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_lrint.c: Likewise.
	* sysdeps/ieee754/flt-32/e_coshf.c: Likewise.
	* sysdeps/ieee754/flt-32/e_exp2f.c: Likewise.
	* sysdeps/ieee754/flt-32/e_expf.c: Likewise.
	* sysdeps/ieee754/flt-32/e_gammaf_r.c: Likewise.
	* sysdeps/ieee754/flt-32/e_j1f.c: Likewise.
	* sysdeps/ieee754/flt-32/e_jnf.c: Likewise.
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c: Likewise.
	* sysdeps/ieee754/flt-32/e_sinhf.c: Likewise.
	* sysdeps/ieee754/flt-32/k_rem_pio2f.c: Likewise.
	* sysdeps/ieee754/flt-32/lgamma_negf.c: Likewise.
	* sysdeps/ieee754/flt-32/s_erff.c: Likewise.
	* sysdeps/ieee754/flt-32/s_llrintf.c: Likewise.
	* sysdeps/ieee754/flt-32/s_lrintf.c: Likewise.
	* sysdeps/ieee754/ldbl-96/gamma_product.c: Likewise.
2018-05-09 00:15:10 +00:00
Joseph Myers
c8235dda72 Avoid excess range overflowing results from cosh, sinh, lgamma (bug 18980).
Various i386 libm functions return values with excess range and
precision; Wilco Dijkstra's patches to make isfinite etc. expand
inline cause this pre-existing issue to result in test failures (when
e.g. a result that overflows float but not long double gets counted as
overflowing for some purposes but not others).

This patch addresses those cases arising from functions defined in C,
adding a math_narrow_eval macro that forces values to memory to
eliminate excess precision if FLT_EVAL_METHOD indicates this is
needed, and is a no-op otherwise.  I'll convert existing uses of
volatile and asm for this purpose to use the new macro later, once
i386 has clean test results again (which requires fixes for .S files
as well).

Tested for x86_64 and x86.  Committed.

	[BZ #18980]
	* sysdeps/generic/math_private.h: Include <float.h>.
	(math_narrow_eval): New macro.
	[FLT_EVAL_METHOD != 0] (excess_precision): Likewise.
	* sysdeps/ieee754/dbl-64/e_cosh.c (__ieee754_cosh): Use
	math_narrow_eval on overflowing return value.
	* sysdeps/ieee754/dbl-64/e_lgamma_r.c (__ieee754_lgamma_r):
	Likewise.
	* sysdeps/ieee754/dbl-64/e_sinh.c (__ieee754_sinh): Likewise.
	* sysdeps/ieee754/flt-32/e_coshf.c (__ieee754_coshf): Likewise.
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r):
	Likewise.
	* sysdeps/ieee754/flt-32/e_sinhf.c (__ieee754_sinhf): Likewise.
2015-09-18 20:00:48 +00:00
Joseph Myers
4648909d56 Fix cosh spurious underflows from expm1 (bug 16354), inaccurate results near 0 (bug 17061).
This patch fixes bug 16354, spurious underflows from cosh when a tiny
argument is passed to expm1 and expm1 correctly underflows although
the final result of cosh should be 1.  As noted in that bug, some
cases are latent because of expm1 implementations not raising
underflow (bug 16353), but all the implementations are fixed
similarly.  They already contained checks for tiny arguments, but the
checks were too late to avoid underflow from expm1 (although they
would avoid underflow from subsequent squaring of the result of
expm1); they are moved before the expm1 calls.

The thresholds used for considering arguments tiny are not
particularly consistent in how they relate to the precision of the
floating-point format in question.  They are, however, all sufficient
to ensure that the round-to-nearest result of cosh is indeed 1 below
the threshold (although sometimes they are smaller than necessary).
But the previous logic did not return 1, but the previously computed 1
+ expm1(abs(x)) value.  And the thresholds in the ldbl-128 and
ldbl-128ibm code (0x1p-71L - I suspect 0x3f8b was intended in the code
instead of 0x3fb8 - and (roughly) 0x1p-55L) are not sufficient for
that value to be 1.  So by moving the test for tiny arguments, and
consequently returning 1 directly now the expm1 value hasn't been
computed by that point, this patch also fixes bug 17061, the (large
number of ulps) inaccuracy for small arguments in those
implementations.  Tests for that bug are duly added.

Tested x86_64 and x86 and ulps updated accordingly.  Also tested for
mips64 and powerpc32 to validate the ldbl-128 and ldbl-128ibm changes.

	[BZ #16354]
	[BZ #17061]
	* sysdeps/ieee754/dbl-64/e_cosh.c (__ieee754_cosh): Check for
	small arguments before calling __expm1.
	* sysdeps/ieee754/flt-32/e_coshf.c (__ieee754_coshf): Check for
	small arguments before calling __expm1f.
	* sysdeps/ieee754/ldbl-128/e_coshl.c (__ieee754_coshl): Check for
	small arguments before calling __expm1l.
	* sysdeps/ieee754/ldbl-128ibm/e_coshl.c (__ieee754_coshl):
	Likewise.
	* sysdeps/ieee754/ldbl-96/e_coshl.c (__ieee754_coshl): Likewise.
	* math/auto-libm-test-in: Add more cosh tests.  Do not allow
	spurious underflow for some cosh tests.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
2014-06-23 20:20:10 +00:00
Richard Henderson
1ed0291c31 Use <> for math.h and math_private.h everywhere.
Entire tree edited via find | grep | sed.
2012-03-09 16:09:10 -08:00
Ulrich Drepper
0ac5ae2335 Optimize libm
libm is now somewhat integrated with gcc's -ffinite-math-only option
and lots of the wrapper functions have been optimized.
2011-10-12 11:27:51 -04:00
Ulrich Drepper
abfbdde177 Update. 1999-07-14 00:54:57 +00:00