glibc/sysdeps/i386/fpu
Wilco Dijkstra c3d466cba1 Remove slow paths from pow
Remove the slow paths from pow.  Like several other double precision math
functions, pow is exactly rounded.  This is not required from math functions
and causes major overheads as it requires multiple fallbacks using higher
precision arithmetic if a result is close to 0.5ULP.  Ridiculous slowdowns
of up to 100000x have been reported when the highest precision path triggers.

All GLIBC math tests pass on AArch64 and x64 (with ULP of pow set to 1).
The worst case error is ~0.506ULP.  A simple test over a few hundred million
values shows pow is 10% faster on average.  This fixes BZ #13932.

	[BZ #13932]
	* sysdeps/ieee754/dbl-64/uexp.h (err_1): Remove.
	* benchtests/pow-inputs: Update comment for slow path cases.
	* manual/probes.texi (slowpow_p10): Delete removed probe.
	(slowpow_p10): Likewise.
	* math/Makefile: Remove halfulp.c and slowpow.c.
	* sysdeps/aarch64/libm-test-ulps: Set ULP of pow to 1.
	* sysdeps/generic/math_private.h (__exp1): Remove error argument.
	(__halfulp): Remove.
	(__slowpow): Remove.
	* sysdeps/i386/fpu/halfulp.c: Delete file.
	* sysdeps/i386/fpu/slowpow.c: Likewise.
	* sysdeps/ia64/fpu/halfulp.c: Likewise.
	* sysdeps/ia64/fpu/slowpow.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_exp.c (__exp1): Remove error argument,
	improve comments and add error analysis.
	* sysdeps/ieee754/dbl-64/e_pow.c (__ieee754_pow): Add error analysis.
	(power1): Remove function:
	(log1): Remove error argument, add error analysis.
	(my_log2): Remove function.
	* sysdeps/ieee754/dbl-64/halfulp.c: Delete file.
	* sysdeps/ieee754/dbl-64/slowpow.c: Likewise.
	* sysdeps/m68k/m680x0/fpu/halfulp.c: Likewise.
	* sysdeps/m68k/m680x0/fpu/slowpow.c: Likewise.
	* sysdeps/powerpc/power4/fpu/Makefile: Remove CPPFLAGS-slowpow.c.
	* sysdeps/x86_64/fpu/libm-test-ulps: Set ULP of pow to 1.
	* sysdeps/x86_64/fpu/multiarch/Makefile: Remove slowpow-fma.c,
	slowpow-fma4.c, halfulp-fma.c, halfulp-fma4.c.
	* sysdeps/x86_64/fpu/multiarch/e_pow-fma.c (__slowpow): Remove define.
	* sysdeps/x86_64/fpu/multiarch/e_pow-fma4.c (__slowpow): Likewise.
	* sysdeps/x86_64/fpu/multiarch/halfulp-fma.c: Delete file.
	* sysdeps/x86_64/fpu/multiarch/halfulp-fma4.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/slowpow-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/slowpow-fma4.c: Likewise.
2018-02-12 10:47:09 +00:00
..
doasin.c
e_acos.S
e_acosf.S
e_acosh.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
e_acoshf.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
e_acoshl.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
e_acosl.c
e_asin.S Refactor i386 libm code forcing underflow exceptions. 2015-09-24 21:41:00 +00:00
e_asinf.S Refactor i386 libm code forcing underflow exceptions. 2015-09-24 21:41:00 +00:00
e_atan2.S Refactor i386 libm code forcing underflow exceptions. 2015-09-24 21:41:00 +00:00
e_atan2f.S Refactor i386 libm code forcing underflow exceptions. 2015-09-24 21:41:00 +00:00
e_atan2l.c
e_atanh.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
e_atanhf.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
e_atanhl.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
e_exp2.S Avoid excess range in results from i386 exp, hypot, pow functions (bug 18980). 2015-09-18 21:53:22 +00:00
e_exp2l.S Refactor i386 libm code forcing underflow exceptions. 2015-09-24 21:41:00 +00:00
e_exp10.S Avoid excess range in results from i386 exp, hypot, pow functions (bug 18980). 2015-09-18 21:53:22 +00:00
e_exp10f.S Avoid excess range in results from i386 exp, hypot, pow functions (bug 18980). 2015-09-18 21:53:22 +00:00
e_exp10l.S
e_exp.S Avoid excess range in results from i386 exp, hypot, pow functions (bug 18980). 2015-09-18 21:53:22 +00:00
e_expl.S Use libm_alias_ldouble in sysdeps/i386/fpu. 2017-11-17 22:54:39 +00:00
e_fmod.S
e_fmodf.S
e_fmodl.c
e_hypot.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
e_hypotf.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
e_ilogb.S
e_ilogbf.S
e_ilogbl.S
e_log2.S Fix log2 (1) in round-downward mode (bug 17042). 2014-06-10 12:07:15 +00:00
e_log2l.S Fix i386/x86_64 log2l (sNaN) (bug 20235). 2016-06-09 18:04:30 +00:00
e_log10.S Fix log10 (1) in round-downward mode (bug 16977). 2014-05-23 12:07:50 +00:00
e_log10f.S Fix log10 (1) in round-downward mode (bug 16977). 2014-05-23 12:07:50 +00:00
e_log10l.S Fix i386/x86_64 log10l (sNaN) (bug 20228). 2016-06-08 22:59:18 +00:00
e_log.S Fix i386/x86_64 log* (1) zero sign for -ffinite-math-only (bug 19213). 2015-11-05 21:56:31 +00:00
e_logl.S Fix i386/x86_64 logl (sNaN) (bug 20227). 2016-06-08 22:24:06 +00:00
e_pow.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
e_powl.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
e_rem_pio2.c
e_remainder.S
e_remainderf.S
e_remainderl.S
e_scalb.S Avoid excess range in results from i386 scalb functions (bug 18981). 2015-09-18 20:34:59 +00:00
e_scalbf.S Avoid excess range in results from i386 scalb functions (bug 18981). 2015-09-18 20:34:59 +00:00
e_scalbl.S Fix i386/x86_64 scalbl with sNaN input (bug 20296). 2016-06-23 22:17:41 +00:00
e_sqrt.S Fix x86 sqrt rounding (bug 14032). 2013-11-29 16:31:16 +00:00
e_sqrtf.S
e_sqrtl.c
fclrexcpt.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fedisblxcpt.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
feenablxcpt.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fegetenv.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fegetexcept.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fegetmode.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fegetround.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
feholdexcpt.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fenv_private.h Add build infrastructure for narrowing libm functions. 2018-02-09 21:18:52 +00:00
fesetenv.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fesetexcept.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fesetmode.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fesetround.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
feupdateenv.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fgetexcptflg.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fraiseexcpt.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fsetexcptflg.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
ftestexcept.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
i386-math-asm.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
Implies
libm-test-ulps i386: Regenerate libm-test-ulps for for gcc 7 on i686 2018-01-06 22:11:40 +01:00
libm-test-ulps-name Do not hardcode platform names in manual/libm-err-tab.pl (bug 14139). 2016-11-04 16:49:06 +00:00
math_private.h Fix math_private.h multiple include guards. 2015-11-20 23:46:23 +00:00
math-tests.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
mpatan2.c
mpatan.c
mpexp.c
mplog.c
mpsqrt.c
s_asinh.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_asinhf.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_asinhl.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_atan.S Use libm_alias_double for i386. 2017-11-28 18:15:44 +00:00
s_atanf.S Use libm_alias_float for i386. 2017-11-29 00:10:35 +00:00
s_atanl.c Use libm_alias_ldouble in sysdeps/i386/fpu. 2017-11-17 22:54:39 +00:00
s_cbrt.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_cbrtf.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_cbrtl.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_ceil.S Use libm_alias_double for i386. 2017-11-28 18:15:44 +00:00
s_ceilf.S Use libm_alias_float for i386. 2017-11-29 00:10:35 +00:00
s_ceill.S Use libm_alias_ldouble in sysdeps/i386/fpu. 2017-11-17 22:54:39 +00:00
s_copysign.S Use libm_alias_double for i386. 2017-11-28 18:15:44 +00:00
s_copysignf.S Use libm_alias_float for i386. 2017-11-29 00:10:35 +00:00
s_copysignl.S Use libm_alias_ldouble in sysdeps/i386/fpu. 2017-11-17 22:54:39 +00:00
s_expm1.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_expm1f.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_expm1l.S
s_f32xaddf64.c Add narrowing add functions. 2018-02-10 02:08:43 +00:00
s_fabs.S Use libm_alias_double for i386. 2017-11-28 18:15:44 +00:00
s_fabsf.S Use libm_alias_float for i386. 2017-11-29 00:10:35 +00:00
s_fabsl.S Use libm_alias_ldouble in sysdeps/i386/fpu. 2017-11-17 22:54:39 +00:00
s_fdim.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_finite.S
s_finitef.S
s_finitel.S
s_floor.S Use libm_alias_double for i386. 2017-11-28 18:15:44 +00:00
s_floorf.S Use libm_alias_float for i386. 2017-11-29 00:10:35 +00:00
s_floorl.S Use libm_alias_ldouble in sysdeps/i386/fpu. 2017-11-17 22:54:39 +00:00
s_fmax.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_fmaxf.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_fmaxl.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_fmin.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_fminf.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_fminl.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_fpclassifyl.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_frexp.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_frexpf.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_frexpl.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_isinfl.c
s_isnanl.c Consistently use uintN_t not u_intN_t in libm. 2017-08-03 19:55:04 +00:00
s_llrint.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_llrintf.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_llrintl.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_log1p.S Refactor i386 libm code forcing underflow exceptions. 2015-09-24 21:41:00 +00:00
s_log1pf.S Refactor i386 libm code forcing underflow exceptions. 2015-09-24 21:41:00 +00:00
s_log1pl.S Fix i386/x86_64 log1pl (sNaN) (bug 20229). 2016-06-08 23:11:42 +00:00
s_logb.S Use libm_alias_double for i386. 2017-11-28 18:15:44 +00:00
s_logbf.S Use libm_alias_float for i386. 2017-11-29 00:10:35 +00:00
s_logbl.c Use libm_alias_ldouble in sysdeps/i386/fpu. 2017-11-17 22:54:39 +00:00
s_lrint.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_lrintf.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_lrintl.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_nearbyint.S Use libm_alias_double for i386. 2017-11-28 18:15:44 +00:00
s_nearbyintf.S Use libm_alias_float for i386. 2017-11-29 00:10:35 +00:00
s_nearbyintl.S Use libm_alias_ldouble in sysdeps/i386/fpu. 2017-11-17 22:54:39 +00:00
s_nextafterl.c Use libm_alias_ldouble in sysdeps/i386/fpu. 2017-11-17 22:54:39 +00:00
s_nexttoward.c Consistently use uintN_t not u_intN_t in libm. 2017-08-03 19:55:04 +00:00
s_nexttowardf.c Consistently use uintN_t not u_intN_t in libm. 2017-08-03 19:55:04 +00:00
s_remquo.S Use libm_alias_double for i386. 2017-11-28 18:15:44 +00:00
s_remquof.S Use libm_alias_float for i386. 2017-11-29 00:10:35 +00:00
s_remquol.S Use libm_alias_ldouble in sysdeps/i386/fpu. 2017-11-17 22:54:39 +00:00
s_rint.S Use libm_alias_double for i386. 2017-11-28 18:15:44 +00:00
s_rintf.S Use libm_alias_float for i386. 2017-11-29 00:10:35 +00:00
s_rintl.c Use libm_alias_ldouble in sysdeps/i386/fpu. 2017-11-17 22:54:39 +00:00
s_scalbln.c
s_scalblnf.c
s_scalblnl.c
s_scalbn.S Avoid excess range in results from i386 scalb functions (bug 18981). 2015-09-18 20:34:59 +00:00
s_scalbnf.S Avoid excess range in results from i386 scalb functions (bug 18981). 2015-09-18 20:34:59 +00:00
s_scalbnl.S Make scalbn set errno (bug 6803). 2015-09-16 21:11:00 +00:00
s_significand.S
s_significandf.S
s_significandl.c
s_trunc.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_truncf.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
s_truncl.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
slowexp.c Revert exp reimplementation (causes test failures). 2017-12-19 18:11:37 +00:00
t_exp.c
Versions
w_sqrt_compat.c Move wrappers to libm-compat-calls-auto 2017-01-04 16:25:04 -02:00
w_sqrt.c Prefer new libm function wrappers for !LIBM_SVID_COMPAT. 2017-09-05 23:35:55 +00:00