Commit Graph

3 Commits

Author SHA1 Message Date
Szabolcs Nagy
a502c5294b Remove the error handling wrapper from pow
Introduce new pow symbol version that doesn't do SVID compatible error
handling.  The standard errno and fp exception based error handling is
inline in the new code and does not have significant overhead.

The wrapper is disabled for sysdeps/ieee754/dbl-64 by using empty
w_pow.c and enabled for targets with their own pow implementation or
ifunc dispatch on __ieee754_pow by including math/w_pow.c.

The compatibility symbol version still uses the wrapper with SVID error
handling around the new code.  There is no new symbol version nor
compatibility code on !LIBM_SVID_COMPAT targets (e.g. riscv).

On targets where previously powl was an alias of pow, now it points to
the compatibility symbol with the wrapper, because it still need the
SVID compatible error handling.  This affects NO_LONG_DOUBLE (e.g. arm)
and LONG_DOUBLE_COMPAT (e.g. alpha) targets as well.

The __pow_finite symbol is now an alias of pow.  Both __pow_finite and
pow set errno and thus not const functions.

The ia64 asm is changed so the compat and new symbol versions map to the
same address.

On x86_64 #include <math.h> was added before macro definitions that
may affect that header.

Tested with build-many-glibcs.py.

	* math/Versions (GLIBC_2.29): Add pow.
	* math/w_pow_compat.c (__pow_compat): Change to versioned compat
	symbol.
	* math/w_pow.c: New file.
	* sysdeps/i386/fpu/w_pow.c: New file.
	* sysdeps/ia64/fpu/e_pow.S: Add versioned symbols.
	* sysdeps/ieee754/dbl-64/e_pow.c (__ieee754_pow): Rename to __pow
	and add necessary aliases.
	* sysdeps/ieee754/dbl-64/w_pow.c: New file.
	* sysdeps/m68k/m680x0/fpu/w_pow.c: New file.
	* sysdeps/mach/hurd/i386/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/alpha/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/arm/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/hppa/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/i386/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/ia64/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/nios2/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist: Update.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/sh/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Update.
	* sysdeps/x86_64/fpu/multiarch/e_pow-fma.c (__ieee754_pow): Rename to
	__pow.
	* sysdeps/x86_64/fpu/multiarch/e_pow-fma4.c (__ieee754_pow): Likewise.
	* sysdeps/x86_64/fpu/multiarch/e_pow.c (__ieee754_pow): Likewise.
	* sysdeps/x86_64/fpu/multiarch/w_pow.c: New file.
2018-11-21 09:58:36 +00:00
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
H.J. Lu
57a72fa350 x86-64: Add FMA multiarch functions to libm
This patch adds multiarch functions optimized with -mfma -mavx2 to libm.
e_pow-fma.c is compiled with $(config-cflags-nofma) due to PR 19003.

	* sysdeps/x86_64/fpu/multiarch/Makefile (libm-sysdep_routines):
	Add e_exp-fma, e_log-fma, e_pow-fma, s_atan-fma, e_asin-fma,
	e_atan2-fma, s_sin-fma, s_tan-fma, mplog-fma, mpa-fma,
	slowexp-fma, slowpow-fma, sincos32-fma, doasin-fma, dosincos-fma,
	halfulp-fma, mpexp-fma, mpatan2-fma, mpatan-fma, mpsqrt-fma,
	and mptan-fma.
	(CFLAGS-doasin-fma.c): New.
	(CFLAGS-dosincos-fma.c): Likewise.
	(CFLAGS-e_asin-fma.c): Likewise.
	(CFLAGS-e_atan2-fma.c): Likewise.
	(CFLAGS-e_exp-fma.c): Likewise.
	(CFLAGS-e_log-fma.c): Likewise.
	(CFLAGS-e_pow-fma.c): Likewise.
	(CFLAGS-halfulp-fma.c): Likewise.
	(CFLAGS-mpa-fma.c): Likewise.
	(CFLAGS-mpatan-fma.c): Likewise.
	(CFLAGS-mpatan2-fma.c): Likewise.
	(CFLAGS-mpexp-fma.c): Likewise.
	(CFLAGS-mplog-fma.c): Likewise.
	(CFLAGS-mpsqrt-fma.c): Likewise.
	(CFLAGS-mptan-fma.c): Likewise.
	(CFLAGS-s_atan-fma.c): Likewise.
	(CFLAGS-sincos32-fma.c): Likewise.
	(CFLAGS-slowexp-fma.c): Likewise.
	(CFLAGS-slowpow-fma.c): Likewise.
	(CFLAGS-s_sin-fma.c): Likewise.
	(CFLAGS-s_tan-fma.c): Likewise.
	* sysdeps/x86_64/fpu/multiarch/doasin-fma.c: New file.
	* sysdeps/x86_64/fpu/multiarch/dosincos-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/e_asin-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/e_atan2-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/e_exp-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/e_log-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/e_pow-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/halfulp-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/ifunc-avx-fma4.h: Likewise.
	* sysdeps/x86_64/fpu/multiarch/ifunc-fma4.h: Likewise.
	* sysdeps/x86_64/fpu/multiarch/mpa-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/mpatan-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/mpatan2-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/mpexp-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/mplog-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/mpsqrt-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/mptan-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_atan-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_sin-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_tan-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/sincos32-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/slowexp-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/slowpow-fma.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/e_asin.c: Rewrite.
	* sysdeps/x86_64/fpu/multiarch/e_atan2.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/e_exp.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/e_log.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/e_pow.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_atan.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_sin.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_tan.c: Likewise.
2017-08-07 08:20:56 -07:00