Commit Graph

17 Commits

Author SHA1 Message Date
Joseph Myers
e44acb2063 Use floor functions not __floor functions in glibc libm.
Similar to the changes that were made to call sqrt functions directly
in glibc, instead of __ieee754_sqrt variants, so that the compiler
could inline them automatically without needing special inline
definitions in lots of math_private.h headers, this patch makes libm
code call floor functions directly instead of __floor variants,
removing the inlines / macros for x86_64 (SSE4.1) and powerpc
(POWER5).

The redirection used to ensure that __ieee754_sqrt does still get
called when the compiler doesn't inline a built-in function expansion
is refactored so it can be applied to other functions; the refactoring
is arranged so it's not limited to unary functions either (it would be
reasonable to use this mechanism for copysign - removing the inline in
math_private_calls.h but also eliminating unnecessary local PLT entry
use in the cases (powerpc soft-float and e500v1, for IBM long double)
where copysign calls don't get inlined).

The point of this change is that more architectures can get floor
calls inlined where they weren't previously (AArch64, for example),
without needing special inline definitions in their math_private.h,
and existing such definitions in math_private.h headers can be
removed.

Note that it's possible that in some cases an inline may be used where
an IFUNC call was previously used - this is the case on x86_64, for
example.  I think the direct calls to floor are still appropriate; if
there's any significant performance cost from inline SSE2 floor
instead of an IFUNC call ending up with SSE4.1 floor, that indicates
that either the function should be doing something else that's faster
than using floor at all, or it should itself have IFUNC variants, or
that the compiler choice of inlining for generic tuning should change
to allow for the possibility that, by not inlining, an SSE4.1 IFUNC
might be called at runtime - but not that glibc should avoid calling
floor internally.  (After all, all the same considerations would apply
to any user program calling floor, where it might either be inlined or
left as an out-of-line call allowing for a possible IFUNC.)

Tested for x86_64, and with build-many-glibcs.py.

	* include/math.h [!_ISOMAC && !(__FINITE_MATH_ONLY__ &&
	__FINITE_MATH_ONLY__ > 0) && !NO_MATH_REDIRECT] (MATH_REDIRECT):
	New macro.
	[!_ISOMAC && !(__FINITE_MATH_ONLY__ && __FINITE_MATH_ONLY__ > 0)
	&& !NO_MATH_REDIRECT] (MATH_REDIRECT_LDBL): Likewise.
	[!_ISOMAC && !(__FINITE_MATH_ONLY__ && __FINITE_MATH_ONLY__ > 0)
	&& !NO_MATH_REDIRECT] (MATH_REDIRECT_F128): Likewise.
	[!_ISOMAC && !(__FINITE_MATH_ONLY__ && __FINITE_MATH_ONLY__ > 0)
	&& !NO_MATH_REDIRECT] (MATH_REDIRECT_UNARY_ARGS): Likewise.
	[!_ISOMAC && !(__FINITE_MATH_ONLY__ && __FINITE_MATH_ONLY__ > 0)
	&& !NO_MATH_REDIRECT] (sqrt): Redirect using MATH_REDIRECT.
	[!_ISOMAC && !(__FINITE_MATH_ONLY__ && __FINITE_MATH_ONLY__ > 0)
	&& !NO_MATH_REDIRECT] (floor): Likewise.
	* sysdeps/aarch64/fpu/s_floor.c: Define NO_MATH_REDIRECT before
	header inclusion.
	* sysdeps/aarch64/fpu/s_floorf.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_floor.c: Likewise.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_floor.c: Likewise.
	* sysdeps/ieee754/float128/s_floorf128.c: Likewise.
	* sysdeps/ieee754/flt-32/s_floorf.c: Likewise.
	* sysdeps/ieee754/ldbl-128/s_floorl.c: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_floorl.c: Likewise.
	* sysdeps/m68k/m680x0/fpu/s_floor_template.c: Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_floor.c: Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_floorf.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_floor.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_floorf.c: Likewise.
	* sysdeps/riscv/rv64/rvd/s_floor.c: Likewise.
	* sysdeps/riscv/rvf/s_floorf.c: Likewise.
	* sysdeps/sparc/sparc64/fpu/multiarch/s_floor.c: Likewise.
	* sysdeps/sparc/sparc64/fpu/multiarch/s_floorf.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_floor.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_floorf.c: Likewise.
	* sysdeps/powerpc/fpu/math_private.h [_ARCH_PWR5X] (__floor):
	Remove macro.
	[_ARCH_PWR5X] (__floorf): Likewise.
	* sysdeps/x86_64/fpu/math_private.h [__SSE4_1__] (__floor): Remove
	inline function.
	[__SSE4_1__] (__floorf): Likewise.
	* math/w_lgamma_main.c (LGFUNC (__lgamma)): Use floor functions
	instead of __floor variants.
	* math/w_lgamma_r_compat.c (__lgamma_r): Likewise.
	* math/w_lgammaf_main.c (LGFUNC (__lgammaf)): Likewise.
	* math/w_lgammaf_r_compat.c (__lgammaf_r): Likewise.
	* math/w_lgammal_main.c (LGFUNC (__lgammal)): Likewise.
	* math/w_lgammal_r_compat.c (__lgammal_r): Likewise.
	* math/w_tgamma_compat.c (__tgamma): Likewise.
	* math/w_tgamma_template.c (M_DECL_FUNC (__tgamma)): Likewise.
	* math/w_tgammaf_compat.c (__tgammaf): Likewise.
	* math/w_tgammal_compat.c (__tgammal): Likewise.
	* sysdeps/ieee754/dbl-64/e_lgamma_r.c (sin_pi): Likewise.
	* sysdeps/ieee754/dbl-64/k_rem_pio2.c (__kernel_rem_pio2):
	Likewise.
	* sysdeps/ieee754/dbl-64/lgamma_neg.c (__lgamma_neg): Likewise.
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c (sin_pif): Likewise.
	* sysdeps/ieee754/flt-32/lgamma_negf.c (__lgamma_negf): Likewise.
	* sysdeps/ieee754/ldbl-128/e_lgammal_r.c (__ieee754_lgammal_r):
	Likewise.
	* sysdeps/ieee754/ldbl-128/e_powl.c (__ieee754_powl): Likewise.
	* sysdeps/ieee754/ldbl-128/lgamma_negl.c (__lgamma_negl):
	Likewise.
	* sysdeps/ieee754/ldbl-128/s_expm1l.c (__expm1l): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_lgammal_r.c (__ieee754_lgammal_r):
	Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_powl.c (__ieee754_powl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/lgamma_negl.c (__lgamma_negl):
	Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_expm1l.c (__expm1l): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_truncl.c (__truncl): Likewise.
	* sysdeps/ieee754/ldbl-96/e_lgammal_r.c (sin_pi): Likewise.
	* sysdeps/ieee754/ldbl-96/lgamma_negl.c (__lgamma_negl): Likewise.
	* sysdeps/powerpc/power5+/fpu/s_modf.c (__modf): Likewise.
	* sysdeps/powerpc/power5+/fpu/s_modff.c (__modff): Likewise.
2018-09-14 13:09:01 +00:00
Wilco Dijkstra
126c4e3f80 Use generic sinf/cosf in lgammaf_r
The internal functions __kernel_sinf and __kernel_cosf are used only by
lgammaf_r.  Removing the internal functions and using the generic sinf
and cosf is better overall.  Benchmarking on Cortex-A72 shows the generic
sinf and cosf are 1.4x and 2.3x faster in the range |x| < PI/4, and 0.66x
and 1.1x for |x| < PI/2, so it should make lgammaf_r faster on average.

GLIBC regression tests pass on AArch64.

	* sysdeps/ieee754/flt-32/e_lgammaf_r.c (sin_pif): Use __sinf/__cosf.
	* sysdeps/ieee754/flt-32/k_cosf.c (__kernel_cosf): Remove all code.
	* sysdeps/ieee754/flt-32/k_sinf.c (__kernel_sinf): Likewise.
2018-08-15 16:01:21 +01:00
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
Wilco Dijkstra
bd8d53bb33 Use fabs(f/l) rather than __fabs
A few math functions still use __fabs(f/l) rather than fabs, which
means they won't be inlined. Rename them so they are inlined.
Also add -fno-builtin-fabsl to nofpu powerpc makefile to work around
BZ #29253.

	* sysdeps/ieee754/dbl-64/e_lgamma_r.c
	(__ieee754_lgamma_r): Use fabs rather than __fabs.
	* sysdeps/ieee754/dbl-64/e_log10.c (__ieee754_log10): Likewise.
	* sysdeps/ieee754/dbl-64/e_log2.c (__ieee754_log2): Likewise.
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c
	(__ieee754_lgammaf_r): Use fabsf rather than __fabsf.
	* sysdeps/ieee754/flt-32/e_log10f.c (__ieee754_log10f): Likewise.
	* sysdeps/ieee754/flt-32/e_log2f.c (__ieee754_log2f): Likewise.
	* sysdeps/ieee754/ldbl-128/e_lgammal_r.c
	(__ieee754_lgammal_r): Use fabsl rather than __fabsl.
	* sysdeps/ieee754/ldbl-128/e_log10l.c (__ieee754_log10l): Likewise.
	* sysdeps/ieee754/ldbl-128/e_log2l.c (__ieee754_log2l): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_lgammal_r.c
	(__ieee754_lgammal_r): Use fabsl rather than __fabsl.
	* sysdeps/ieee754/ldbl-128ibm/e_log10l.c (__ieee754_log10l): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_log2l.c (__ieee754_log2l): Likewise.
	* sysdeps/powerpc/nofpu/Makefile: Add -fno-builtin-fabsl for BZ #29253.
2017-09-29 18:54:24 +01:00
Zack Weinberg
9090848d06 Narrowing the visibility of libc-internal.h even further.
posix/wordexp-test.c used libc-internal.h for PTR_ALIGN_DOWN; similar
to what was done with libc-diag.h, I have split the definitions of
cast_to_integer, ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and PTR_ALIGN_DOWN
to a new header, libc-pointer-arith.h.

It then occurred to me that the remaining declarations in libc-internal.h
are mostly to do with early initialization, and probably most of the
files including it, even in the core code, don't need it anymore.  Indeed,
only 19 files actually need what remains of libc-internal.h.  23 others
need libc-diag.h instead, and 12 need libc-pointer-arith.h instead.
No file needs more than one of them, and 16 don't need any of them!

So, with this patch, libc-internal.h stops including libc-diag.h as
well as losing the pointer arithmetic macros, and all including files
are adjusted.

        * include/libc-pointer-arith.h: New file.  Define
	cast_to_integer, ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and
        PTR_ALIGN_DOWN here.
        * include/libc-internal.h: Definitions of above macros
	moved from here.  Don't include libc-diag.h anymore either.
	* posix/wordexp-test.c: Include stdint.h and libc-pointer-arith.h.
        Don't include libc-internal.h.

	* debug/pcprofile.c, elf/dl-tunables.c, elf/soinit.c, io/openat.c
	* io/openat64.c, misc/ptrace.c, nptl/pthread_clock_gettime.c
	* nptl/pthread_clock_settime.c, nptl/pthread_cond_common.c
	* string/strcoll_l.c, sysdeps/nacl/brk.c
	* sysdeps/unix/clock_settime.c
	* sysdeps/unix/sysv/linux/i386/get_clockfreq.c
	* sysdeps/unix/sysv/linux/ia64/get_clockfreq.c
	* sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c
	* sysdeps/unix/sysv/linux/sparc/sparc64/get_clockfreq.c:
	Don't include libc-internal.h.

	* elf/get-dynamic-info.h, iconv/loop.c
	* iconvdata/iso-2022-cn-ext.c, locale/weight.h, locale/weightwc.h
	* misc/reboot.c, nis/nis_table.c, nptl_db/thread_dbP.h
	* nscd/connections.c, resolv/res_send.c, soft-fp/fmadf4.c
	* soft-fp/fmasf4.c, soft-fp/fmatf4.c, stdio-common/vfscanf.c
	* sysdeps/ieee754/dbl-64/e_lgamma_r.c
	* sysdeps/ieee754/dbl-64/k_rem_pio2.c
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c
	* sysdeps/ieee754/flt-32/k_rem_pio2f.c
	* sysdeps/ieee754/ldbl-128/k_tanl.c
	* sysdeps/ieee754/ldbl-128ibm/k_tanl.c
	* sysdeps/ieee754/ldbl-96/e_lgammal_r.c
	* sysdeps/ieee754/ldbl-96/k_tanl.c, sysdeps/nptl/futex-internal.h:
	Include libc-diag.h instead of libc-internal.h.

        * elf/dl-load.c, elf/dl-reloc.c, locale/programs/locarchive.c
        * nptl/nptl-init.c, string/strcspn.c, string/strspn.c
	* malloc/malloc.c, sysdeps/i386/nptl/tls.h
	* sysdeps/nacl/dl-map-segments.h, sysdeps/x86_64/atomic-machine.h
	* sysdeps/unix/sysv/linux/spawni.c
        * sysdeps/x86_64/nptl/tls.h:
        Include libc-pointer-arith.h instead of libc-internal.h.

	* elf/get-dynamic-info.h, sysdeps/nacl/dl-map-segments.h
	* sysdeps/x86_64/atomic-machine.h:
        Add multiple include guard.
2017-03-01 20:33:46 -05:00
Tulio Magno Quites Machado Filho
51b34a9c47 Fix lgamma*, log10* and log2* results [BZ #21171]
lgamma(-x) should return +Inf and raise divide-by-zero.
log10(+-0) and log2(+-0) should return -Inf and raise divide-by-zero.

Tested on powerpc, powerpc64, powerpc64le and x86_64.

	[BZ #21171]
	* sysdeps/ieee754/dbl-64/e_lgamma_r.c (__ieee754_lgamma_r): Return
	+Inf and raise divide-by-zero when x is negative.
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r): Likewise.
	* sysdeps/ieee754/ldbl-128/e_lgammal_r.c (__ieee754_lgammal_r): Likewise.

	* sysdeps/ieee754/dbl-64/e_log10.c (__ieee754_log10):  Return
	-Inf and raise divide-by-zero when x = +-0.
	* sysdeps/ieee754/dbl-64/e_log2.c (__ieee754_log2): Likewise.
	* sysdeps/ieee754/flt-32/e_log10f.c (__ieee754_log10f):	Likewise.
	* sysdeps/ieee754/flt-32/e_log2f.c (__ieee754_log2f): Likewise.
	* sysdeps/ieee754/ldbl-128/e_log10l.c (__ieee754_log10l): Likewise.
	* sysdeps/ieee754/ldbl-128/e_log2l.c (__ieee754_log2l): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_log10l.c (__ieee754_log10l): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_log2l.c (__ieee754_log2l): Likewise.
2017-02-17 09:07:57 -02:00
Joseph Myers
f1d237df1e Remove GCC version conditionals on -Wmaybe-uninitialized pragmas.
One common case of __GNUC_PREREQ (4, 7) conditionals is use of
diagnostic control pragmas for -Wmaybe-uninitialized, an option
introduced in GCC 4.7 where older GCC needed -Wuninitialized to be
controlled instead if the warning appeared with older GCC.  This patch
removes such conditionals.

(There remain several older uses of -Wno-uninitialized in makefiles
that still need to be converted to diagnostic control pragmas if the
issue is still present with current sources and supported GCC
versions, and it's likely that in most cases those pragmas also will
end up controlling -Wmaybe-uninitialized.)

Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch, except for libresolv
since res_send.c contains assertions whose line numbers are changed by
the patch).

	* resolv/res_send.c (send_vc) [__GNUC_PREREQ (4, 7)]: Make code
	unconditional.
	* soft-fp/fmadf4.c [__GNUC_PREREQ (4, 7)]: Likewise.
	[!__GNUC_PREREQ (4, 7)]: Remove conditional code.
	* soft-fp/fmasf4.c [__GNUC_PREREQ (4, 7)]: Make code
	unconditional.
	[!__GNUC_PREREQ (4, 7)]: Remove conditional code.
	* soft-fp/fmatf4.c [__GNUC_PREREQ (4, 7)]: Make code
	unconditional.
	[!__GNUC_PREREQ (4, 7)]: Remove conditional code.
	* stdlib/setenv.c
	[((__GNUC__ << 16) + __GNUC_MINOR__) >= ((4 << 16) + 7)]: Make
	code unconditional.
	[!(((__GNUC__ << 16) + __GNUC_MINOR__) >= ((4 << 16) + 7))]:
	Remove conditional code.
	* sysdeps/ieee754/dbl-64/e_lgamma_r.c
	(__ieee754_lgamma_r) [__GNUC_PREREQ (4, 7)]: Make code
	unconditional.
	(__ieee754_lgamma_r) [!__GNUC_PREREQ (4, 7)]: Remove conditional
	code.
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c
	(__ieee754_lgammaf_r) [__GNUC_PREREQ (4, 7)]: Make code
	unconditional.
	(__ieee754_lgammaf_r) [!__GNUC_PREREQ (4, 7)]: Remove conditional
	code.
	* sysdeps/ieee754/ldbl-128/k_tanl.c
	(__kernel_tanl) [__GNUC_PREREQ (4, 7)]: Make code unconditional.
	(__kernel_tanl) [!__GNUC_PREREQ (4, 7)]: Remove conditional code.
	* sysdeps/ieee754/ldbl-128ibm/k_tanl.c
	(__kernel_tanl) [__GNUC_PREREQ (4, 7)]: Make code unconditional.
	(__kernel_tanl) [!__GNUC_PREREQ (4, 7)]: Remove conditional code.
	* sysdeps/ieee754/ldbl-96/e_lgammal_r.c
	(__ieee754_lgammal_r) [__GNUC_PREREQ (4, 7)]: Make code
	unconditional.
	(__ieee754_lgammal_r) [!__GNUC_PREREQ (4, 7)]: Remove conditional
	code.
	* sysdeps/ieee754/ldbl-96/k_tanl.c
	(__kernel_tanl) [__GNUC_PREREQ (4, 7)]: Make code unconditional.
	(__kernel_tanl) [!__GNUC_PREREQ (4, 7)]: Remove conditional code.
2015-10-27 23:42:20 +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
050f29c188 Fix lgamma (negative) inaccuracy (bug 2542, bug 2543, bug 2558).
The existing implementations of lgamma functions (except for the ia64
versions) use the reflection formula for negative arguments.  This
suffers large inaccuracy from cancellation near zeros of lgamma (near
where the gamma function is +/- 1).

This patch fixes this inaccuracy.  For arguments above -2, there are
no zeros and no large cancellation, while for sufficiently large
negative arguments the zeros are so close to integers that even for
integers +/- 1ulp the log(gamma(1-x)) term dominates and cancellation
is not significant.  Thus, it is only necessary to take special care
about cancellation for arguments around a limited number of zeros.

Accordingly, this patch uses precomputed tables of relevant zeros,
expressed as the sum of two floating-point values.  The log of the
ratio of two sines can be computed accurately using log1p in cases
where log would lose accuracy.  The log of the ratio of two gamma(1-x)
values can be computed using Stirling's approximation (the difference
between two values of that approximation to lgamma being computable
without computing the two values and then subtracting), with
appropriate adjustments (which don't reduce accuracy too much) in
cases where 1-x is too small to use Stirling's approximation directly.

In the interval from -3 to -2, using the ratios of sines and of
gamma(1-x) can still produce too much cancellation between those two
parts of the computation (and that interval is also the worst interval
for computing the ratio between gamma(1-x) values, which computation
becomes more accurate, while being less critical for the final result,
for larger 1-x).  Because this can result in errors slightly above
those accepted in glibc, this interval is instead dealt with by
polynomial approximations.  Separate polynomial approximations to
(|gamma(x)|-1)(x-n)/(x-x0) are used for each interval of length 1/8
from -3 to -2, where n (-3 or -2) is the nearest integer to the
1/8-interval and x0 is the zero of lgamma in the relevant half-integer
interval (-3 to -2.5 or -2.5 to -2).

Together, the two approaches are intended to give sufficient accuracy
for all negative arguments in the problem range.  Outside that range,
the previous implementation continues to be used.

Tested for x86_64, x86, mips64 and powerpc.  The mips64 and powerpc
testing shows up pre-existing problems for ldbl-128 and ldbl-128ibm
with large negative arguments giving spurious "invalid" exceptions
(exposed by newly added tests for cases this patch doesn't affect the
logic for); I'll address those problems separately.

	[BZ #2542]
	[BZ #2543]
	[BZ #2558]
	* sysdeps/ieee754/dbl-64/e_lgamma_r.c (__ieee754_lgamma_r): Call
	__lgamma_neg for arguments from -28.0 to -2.0.
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r): Call
	__lgamma_negf for arguments from -15.0 to -2.0.
	* sysdeps/ieee754/ldbl-128/e_lgammal_r.c (__ieee754_lgammal_r):
	Call __lgamma_negl for arguments from -48.0 or -50.0 to -2.0.
	* sysdeps/ieee754/ldbl-96/e_lgammal_r.c (__ieee754_lgammal_r):
	Call __lgamma_negl for arguments from -33.0 to -2.0.
	* sysdeps/ieee754/dbl-64/lgamma_neg.c: New file.
	* sysdeps/ieee754/dbl-64/lgamma_product.c: Likewise.
	* sysdeps/ieee754/flt-32/lgamma_negf.c: Likewise.
	* sysdeps/ieee754/flt-32/lgamma_productf.c: Likewise.
	* sysdeps/ieee754/ldbl-128/lgamma_negl.c: Likewise.
	* sysdeps/ieee754/ldbl-128/lgamma_productl.c: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/lgamma_negl.c: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/lgamma_productl.c: Likewise.
	* sysdeps/ieee754/ldbl-96/lgamma_negl.c: Likewise.
	* sysdeps/ieee754/ldbl-96/lgamma_product.c: Likewise.
	* sysdeps/ieee754/ldbl-96/lgamma_productl.c: Likewise.
	* sysdeps/generic/math_private.h (__lgamma_negf): New prototype.
	(__lgamma_neg): Likewise.
	(__lgamma_negl): Likewise.
	(__lgamma_product): Likewise.
	(__lgamma_productl): Likewise.
	* math/Makefile (libm-calls): Add lgamma_neg and lgamma_product.
	* math/auto-libm-test-in: Add more tests of lgamma.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2015-09-10 22:27:58 +00:00
Joseph Myers
9124ccf76a Fix lgamma implementations for -Wuninitialized.
If you remove the "override CFLAGS += -Wno-uninitialized" in
math/Makefile, you get errors from lgamma implementations of the form:

../sysdeps/ieee754/dbl-64/e_lgamma_r.c: In function '__ieee754_lgamma_r':
../sysdeps/ieee754/dbl-64/e_lgamma_r.c:297:13: error: 'nadj' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  if(hx<0) r = nadj - r;

This is one of the standard kinds of false positive uninitialized
warnings: nadj is set under a certain condition, and then later used
under the same condition.  This patch uses DIAG_* macros to suppress
the warning on the use of nadj.  The ldbl-128 / ldbl-128ibm
implementation has a substantially different structure that avoids
this issue.

Tested for x86_64.  (In fact this patch eliminates the need for that
-Wno-uninitialized on x86_64, but I want to test on more architectures
before removing it.)

	* sysdeps/ieee754/dbl-64/e_lgamma_r.c: Include <libc-internal.h>.
	(__ieee754_lgamma_r): Ignore uninitialized warnings around use of
	NADJ.
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c: Include <libc-internal.h>.
	(__ieee754_lgammaf_r): Ignore uninitialized warnings around use of
	NADJ.
	* sysdeps/ieee754/ldbl-96/e_lgammal_r.c: Include <libc-internal.h>.
	(__ieee754_lgammal_r): Ignore uninitialized warnings around use of
	NADJ.
2015-05-21 23:44:33 +00:00
Joseph Myers
ff069f024a Fix lgammaf spurious underflows (bug 18220).
The flt-32 implementation of lgammaf produces spurious underflow
exceptions for some large arguments, because of calculations involving
x^-2 multiplied by small constants.  This patch fixes this by
adjusting the threshold for a simpler computation to 2**26 (the error
in the simpler computation is on the order of 0.5 * log (x), for a
result on the order of x * log (x)).

Tested for x86_64 and x86.

	[BZ #18220]
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r): Use
	2**26 not 2**58 as threshold for returning x * (log (x) - 1).
	* math/auto-libm-test-in: Add another test of lgamma.
	* math/auto-libm-test-out: Regenerated.
2015-05-15 17:21:08 +00:00
Joseph Myers
ffa3cd7f1a Fix lgammaf spurious underflow (bug 15427). 2013-09-03 15:32:54 +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
c039eedd66 [BZ #4407]
* sysdeps/ieee754/dbl-64/e_lgamma_r.c: Fix *signgamp for -0.0.
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c: Likewise.
	* sysdeps/ieee754/ldbl-96/e_lgammal_r.c: Likewise.
	* math/libm-test.inc: Add test for this case.

	Half the patch by Christian Iseli <christian.iseli@licr.org>.
2007-10-06 18:37:30 +00:00
Ulrich Drepper
f30e0cd35e Update.
1999-10-19  Ulrich Drepper  <drepper@cygnus.com>

	* sysdeps/i386/fpu/s_nextafterl.c: Add __nextafterl and nextafterl
	aliases.

	* sysdeps/ieee754/flt-32/e_lgammaf_r.c: Don't handle -Inf special.

	* sysdeps/ieee754/flt-32/e_gammaf_r.c (__ieee754_gammaf_r): Check
	for -Inf and return NaN.

	* math/gen-libm-test.pl: Fix program name in help message.

	* math/libm-test.inc (check_complex): It's Imaginary, not Complex.

	* math/libm-test.inc (gamma_test): Result of gamma(-inf) is +inf.

	* sysdeps/i386/Implies: Correct order of libm directories.
1999-10-20 03:20:31 +00:00
Ulrich Drepper
abfbdde177 Update. 1999-07-14 00:54:57 +00:00