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powerpc: hypot refactor and optimization 

The powerpc hypot is slight optimized by:

  - Commit 8df4e219e4, both isnan and isinf are always inlined and thus
    the check TEST_INF_NAN does not make sense anymore.  The generic
    check for POWER7 should be faster on all powerpc configuration.

  - The redundant check 'y > two60factor && (x / y) > two60' is removed.

Both changes leads to unrequired ifunc especialization for power7 and
thus they are removed.  Finally The code is also cleanup a bit by inlining
the constants floating points.

The performance changes using the hypot benchtests are:

  - POWER9 without patch:
    "hypot": {
     "overflow": {
      "duration": 4.98585e+09,
      "iterations": 4.84932e+08,
      "max": 46.551,
      "min": 10.229,
      "mean": 10.2815
     },
     "higher_two500": {
      "duration": 5.00192e+09,
      "iterations": 4.24843e+08,
      "max": 33.319,
      "min": 11.606,
      "mean": 11.7736
     },
     "subnormal": {
      "duration": 5.0075e+09,
      "iterations": 4.06792e+08,
      "max": 22.178,
      "min": 12.15,
      "mean": 12.3097
     },
     "less_two500": {
      "duration": 5.00685e+09,
      "iterations": 4.08772e+08,
      "max": 22.784,
      "min": 12.052,
      "mean": 12.2485
     },
     "default": {
      "duration": 5.06002e+09,
      "iterations": 4.09894e+08,
      "max": 20.648,
      "min": 11.874,
      "mean": 12.3447
     }
    }

  - POWER9 with patch:
    "hypot": {
     "overflow": {
      "duration": 4.91848e+09,
      "iterations": 7.28039e+08,
      "max": 47.958,
      "min": 6.436,
      "mean": 6.75579
     },
     "higher_two500": {
      "duration": 4.9359e+09,
      "iterations": 6.63376e+08,
      "max": 20.783,
      "min": 7.321,
      "mean": 7.44057
     },
     "subnormal": {
      "duration": 4.9479e+09,
      "iterations": 6.19772e+08,
      "max": 18.856,
      "min": 7.817,
      "mean": 7.98341
     },
     "less_two500": {
      "duration": 4.94275e+09,
      "iterations": 6.3889e+08,
      "max": 17.452,
      "min": 7.597,
      "mean": 7.73647
     },
     "default": {
      "duration": 5.03645e+09,
      "iterations": 5.70718e+08,
      "max": 18.904,
      "min": 8.55,
      "mean": 8.82476
     }
    }

  - POWER7 without patch
    "hypot": {
     "overflow": {
      "duration": 4.86637e+09,
      "iterations": 6.43196e+08,
      "max": 53.958,
      "min": 7.328,
      "mean": 7.56592
     },
     "higher_two500": {
      "duration": 4.99842e+09,
      "iterations": 3.11012e+08,
      "max": 78.227,
      "min": 15.696,
      "mean": 16.0715
     },
     "subnormal": {
      "duration": 4.99841e+09,
      "iterations": 3.08935e+08,
      "max": 51.392,
      "min": 15.983,
      "mean": 16.1795
     },
     "less_two500": {
      "duration": 5.00108e+09,
      "iterations": 2.99464e+08,
      "max": 73.247,
      "min": 16.416,
      "mean": 16.7001
     },
     "default": {
      "duration": 5.04645e+09,
      "iterations": 3.52608e+08,
      "max": 70.073,
      "min": 13.38,
      "mean": 14.3118
     }
    }

  - POWER7 with patch
    "hypot": {
     "overflow": {
      "duration": 4.80785e+09,
      "iterations": 8.00001e+08,
      "max": 66.262,
      "min": 5.888,
      "mean": 6.00981
     },
     "higher_two500": {
      "duration": 4.9859e+09,
      "iterations": 3.39449e+08,
      "max": 5148.44,
      "min": 14.539,
      "mean": 14.6882
     },
     "subnormal": {
      "duration": 4.9905e+09,
      "iterations": 3.28874e+08,
      "max": 64.905,
      "min": 14.971,
      "mean": 15.1745
     },
     "less_two500": {
      "duration": 4.99494e+09,
      "iterations": 3.19755e+08,
      "max": 103.696,
      "min": 14.972,
      "mean": 15.6211
     },
     "default": {
      "duration": 5.03951e+09,
      "iterations": 4.02502e+08,
      "max": 61.008,
      "min": 12.368,
      "mean": 12.5205
     }
    }

Checked on powerpc-linux-gnu (built without --with-cpu, with
--with-cpu=power4 and with --with-cpu=power5+ and --disable-multi-arch),
powerpc64-linux-gnu (built without --with-cp and with --with-cpu=power5+
and --disable-multi-arch).

	* sysdeps/powerpc/fpu/e_hypot.c (two60, two500, two600, two1022,
	twoM500, twoM600, two60factor, pdnum): Remove.
	(TEST_INFO_NAN, GET_TW0_HIGH_WORD): Remove macro.
	(__ieee754_hypot): Replace static variables with inline definition,
	remove ununsed branches.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
	(libm-sysdep_routines): Remove e_hypot-* objects.
	(CFLAGS-e_hypot-power7.c, CFLAGS-e_hypotf-power7.c): Remove rule.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypot-power7.c: Remove
	file.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypot-ppc64.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypot.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypotf-power7.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypotf-ppc64.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypotf.c: Likewise.

Reviewed-by: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>
This commit is contained in:
Adhemerval Zanella 2019-03-18 17:40:50 +00:00
parent f215dbbdf1
commit 69461d9896
9 changed files with 39 additions and 232 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
ChangeLog
View File

@ -1,5 +1,21 @@
2019-07-08 Adhemerval Zanella <adhemerval.zanella@linaro.org>
* sysdeps/powerpc/fpu/e_hypot.c (two60, two500, two600, two1022,
twoM500, twoM600, two60factor, pdnum): Remove.
(TEST_INFO_NAN, GET_TW0_HIGH_WORD): Remove macro.
(__ieee754_hypot): Replace static variables with inline definition,
remove ununsed branches.
* sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
(libm-sysdep_routines): Remove e_hypot-* objects.
(CFLAGS-e_hypot-power7.c, CFLAGS-e_hypotf-power7.c): Remove rule.
* sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypot-power7.c: Remove
file.
* sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypot-ppc64.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypot.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypotf-power7.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypotf-ppc64.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypotf.c: Likewise.
* benchtests/Makefile (bench-math): Add hypot.
* benchtests/hypot-inputs: New file.

94
sysdeps/powerpc/fpu/e_hypot.c
View File

@ -22,15 +22,6 @@
#include <math-underflow.h>
#include <stdint.h>
static const double two60 = 1.152921504606847e+18;
static const double two500 = 3.2733906078961419e+150;
static const double two600 = 4.149515568880993e+180;
static const double two1022 = 4.49423283715579e+307;
static const double twoM500 = 3.054936363499605e-151;
static const double twoM600 = 2.4099198651028841e-181;
static const double two60factor = 1.5592502418239997e+290;
static const double pdnum = 2.225073858507201e-308;
/* __ieee754_hypot(x,y)
*
* This a FP only version without any FP->INT conversion.
@ -39,53 +30,18 @@ static const double pdnum = 2.225073858507201e-308;
* is needed.
*/
#ifdef _ARCH_PWR7
/* POWER7 isinf and isnan optimization are fast. */
# define TEST_INF_NAN(x, y) \
if ((isinf(x) || isinf(y)) \
&& !issignaling (x) && !issignaling (y)) \
return INFINITY; \
if (isnan(x) || isnan(y)) \
return x + y;
# else
/* For POWER6 and below isinf/isnan triggers LHS and PLT calls are
* costly (especially for POWER6). */
# define GET_TW0_HIGH_WORD(d1,d2,i1,i2) \
do { \
ieee_double_shape_type gh_u1; \
ieee_double_shape_type gh_u2; \
gh_u1.value = (d1); \
gh_u2.value = (d2); \
(i1) = gh_u1.parts.msw & 0x7fffffff; \
(i2) = gh_u2.parts.msw & 0x7fffffff; \
} while (0)
# define TEST_INF_NAN(x, y) \
do { \
uint32_t hx, hy; \
GET_TW0_HIGH_WORD(x, y, hx, hy); \
if (hy > hx) { \
uint32_t ht = hx; hx = hy; hy = ht; \
} \
if (hx >= 0x7ff00000) { \
if ((hx == 0x7ff00000 || hy == 0x7ff00000) \
&& !issignaling (x) && !issignaling (y)) \
return INFINITY; \
return x + y; \
} \
} while (0)
#endif
double
__ieee754_hypot (double x, double y)
{
if ((isinf (x) || isinf (y))
&& !issignaling (x) && !issignaling (y))
return INFINITY;
if (isnan (x) || isnan (y))
return x + y;
x = fabs (x);
y = fabs (y);
TEST_INF_NAN (x, y);
if (y > x)
{
double t = x;
@ -94,40 +50,34 @@ __ieee754_hypot (double x, double y)
}
if (y == 0.0)
return x;
/* if y is higher enough, y * 2^60 might overflow. The tests if
y >= 1.7976931348623157e+308/2^60 (two60factor) and uses the
appropriate check to avoid the overflow exception generation. */
if (y > two60factor)
if (y <= 0x1.fffffffffffffp+963 && x > (y * 0x1p+60))
return x + y;
if (x > 0x1p+500)
{
if ((x / y) > two60)
return x + y;
x *= 0x1p-600;
y *= 0x1p-600;
return sqrt (x * x + y * y) / 0x1p-600;
}
else
if (y < 0x1p-500)
{
if (x > (y * two60))
return x + y;
}
if (x > two500)
{
x *= twoM600;
y *= twoM600;
return sqrt (x * x + y * y) / twoM600;
}
if (y < twoM500)
{
if (y <= pdnum)
if (y <= 0x0.fffffffffffffp-1022)
{
x *= two1022;
y *= two1022;
double ret = sqrt (x * x + y * y) / two1022;
x *= 0x1p+1022;
y *= 0x1p+1022;
double ret = sqrt (x * x + y * y) / 0x1p+1022;
math_check_force_underflow_nonneg (ret);
return ret;
}
else
{
x *= two600;
y *= two600;
return sqrt (x * x + y * y) / two600;
x *= 0x1p+600;
y *= 0x1p+600;
return sqrt (x * x + y * y) / 0x1p+600;
}
}
return sqrt (x * x + y * y);

5
sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
View File

@ -8,8 +8,7 @@ sysdep_calls := s_modf-power5+ s_modf-ppc64 \
sysdep_routines += $(sysdep_calls)
libm-sysdep_routines += s_logb-power7 s_logbf-power7 \
s_logbl-power7 s_logb-ppc64 s_logbf-ppc64 \
s_logbl-ppc64 e_hypot-ppc64 \
e_hypot-power7 e_hypotf-ppc64 e_hypotf-power7 \
s_logbl-ppc64 \
$(sysdep_calls:s_%=m_%)
CFLAGS-s_logbf-power7.c = -mcpu=power7
@ -17,8 +16,6 @@ CFLAGS-s_logbl-power7.c = -mcpu=power7
CFLAGS-s_logb-power7.c = -mcpu=power7
CFLAGS-s_modf-power5+.c = -mcpu=power5+
CFLAGS-s_modff-power5+.c = -mcpu=power5+
CFLAGS-e_hypot-power7.c = -mcpu=power7
CFLAGS-e_hypotf-power7.c = -mcpu=power7
# These files quiet sNaNs in a way that is optimized away without
# -fsignaling-nans.

19
sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypot-power7.c
View File

@ -1,19 +0,0 @@
/* __ieee_hypot() POWER7 version.
Copyright (C) 2013-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <sysdeps/powerpc/powerpc32/power4/fpu/multiarch/e_hypot-power7.c>

26
sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypot-ppc64.c
View File

@ -1,26 +0,0 @@
/* __ieee_hypot() PowerPC64 version.
Copyright (C) 2013-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <math.h>
#undef strong_alias
#define strong_alias(a, b)
#define __ieee754_hypot __ieee754_hypot_ppc64
#include <sysdeps/powerpc/fpu/e_hypot.c>

33
sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypot.c
View File

@ -1,33 +0,0 @@
/* Multiple versions of ieee754_hypot.
Copyright (C) 2013-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <math.h>
#include <math_private.h>
#include <math_ldbl_opt.h>
#include <shlib-compat.h>
#include "init-arch.h"
extern __typeof (__ieee754_hypot) __ieee754_hypot_ppc64 attribute_hidden;
extern __typeof (__ieee754_hypot) __ieee754_hypot_power7 attribute_hidden;
libc_ifunc (__ieee754_hypot,
(hwcap & PPC_FEATURE_ARCH_2_06)
? __ieee754_hypot_power7
: __ieee754_hypot_ppc64);
strong_alias (__ieee754_hypot, __hypot_finite)

19
sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypotf-power7.c
View File

@ -1,19 +0,0 @@
/* __ieee_hypotf() POWER7 version.
Copyright (C) 2013-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <sysdeps/powerpc/powerpc32/power4/fpu/multiarch/e_hypotf-power7.c>

26
sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypotf-ppc64.c
View File

@ -1,26 +0,0 @@
/* __ieee_hypot() PowerPC64 version.
Copyright (C) 2013-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <math.h>
#undef strong_alias
#define strong_alias(a, b)
#define __ieee754_hypotf __ieee754_hypotf_ppc64
#include <sysdeps/powerpc/fpu/e_hypotf.c>

33
sysdeps/powerpc/powerpc64/fpu/multiarch/e_hypotf.c
View File

@ -1,33 +0,0 @@
/* Multiple versions of ieee754_hypot.
Copyright (C) 2013-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <math.h>
#include <math_private.h>
#include <math_ldbl_opt.h>
#include <shlib-compat.h>
#include "init-arch.h"
extern __typeof (__ieee754_hypotf) __ieee754_hypotf_ppc64 attribute_hidden;
extern __typeof (__ieee754_hypotf) __ieee754_hypotf_power7 attribute_hidden;
libc_ifunc (__ieee754_hypotf,
(hwcap & PPC_FEATURE_ARCH_2_06)
? __ieee754_hypotf_power7
: __ieee754_hypotf_ppc64);
strong_alias (__ieee754_hypotf, __hypotf_finite)