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[PATCH] Move multiprecision constant mpone into static scope
- From: Siddhesh Poyarekar <siddhesh at redhat dot com>
- To: libc-alpha at sourceware dot org
- Date: Thu, 20 Dec 2012 18:58:07 +0530
- Subject: [PATCH] Move multiprecision constant mpone into static scope
Hi,
The constant representation of 1 in the multiprecision implementation
in libm is repeated in a bunch of places as a local variable. This is
slow in comparison to having it declared in static scope (and hence
instantiated only once). Attached patch does exactly that. I have
verified that this does not cause any regressions in the testsuite.
As for verification of performance, I have tested this with the pow
function using the test case described in this blog:
http://entropymine.com/imageworsener/slowpow/
using the following commandline:
time ./powtest 1000000 1.0000000000000020 1.5000000050000000
The patch takes off approx 0.1 second with the patch. OK for 2.18?
Siddhesh
ChangeLog:
2012-12-20 Siddhesh Poyarekar <siddhesh@redhat.com>
* sysdeps/ieee754/dbl-64/mpa.c [! NO__CONST]: New constant
MPONE.
* sysdeps/ieee754/dbl-64/mpa.h: Declare MPONE.
* sysdeps/ieee754/dbl-64/mpatan.c (__mpatan): Remove local
variable MPONE.
* sysdeps/ieee754/dbl-64/mpatan2.c (__mpatan2): Likewise.
* sysdeps/ieee754/dbl-64/mpexp.c (__mpexp): Likewise.
* sysdeps/ieee754/dbl-64/mplog.c (__mplog): Remove mplog.h
include directive. Remove local variable MPONE.
* sysdeps/ieee754/dbl-64/mplog.h: Remove.
* sysdeps/x86_64/fpu/multiarch/mpa-avx.c: Define NO__CONST.
* sysdeps/x86_64/fpu/multiarch/mpa-fma4.c: Likewise.
diff --git a/sysdeps/ieee754/dbl-64/mpa.c b/sysdeps/ieee754/dbl-64/mpa.c
index 7e0ee44..b5d25ed 100644
--- a/sysdeps/ieee754/dbl-64/mpa.c
+++ b/sysdeps/ieee754/dbl-64/mpa.c
@@ -51,6 +51,10 @@
# define SECTION
#endif
+#ifndef NO__CONST
+const mp_no mpone = {1, {1.0, 1.0}};
+#endif
+
#ifndef NO___ACR
/* mcr() compares the sizes of the mantissas of two multiple precision */
/* numbers. Mantissas are compared regardless of the signs of the */
diff --git a/sysdeps/ieee754/dbl-64/mpa.h b/sysdeps/ieee754/dbl-64/mpa.h
index 26ae2ac..4fdecb6 100644
--- a/sysdeps/ieee754/dbl-64/mpa.h
+++ b/sysdeps/ieee754/dbl-64/mpa.h
@@ -54,6 +54,8 @@ typedef struct {/* This structure holds the details of a multi-precision */
typedef union { int i[2]; double d; } number;
+extern const mp_no mpone;
+
#define X x->d
#define Y y->d
#define Z z->d
diff --git a/sysdeps/ieee754/dbl-64/mpatan.c b/sysdeps/ieee754/dbl-64/mpatan.c
index 80637e5..d897bbb 100644
--- a/sysdeps/ieee754/dbl-64/mpatan.c
+++ b/sysdeps/ieee754/dbl-64/mpatan.c
@@ -48,9 +48,6 @@ __mpatan(mp_no *x, mp_no *y, int p) {
int i,m,n;
double dx;
mp_no
- mpone = {0,{0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
- 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
- 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0}},
mptwo = {0,{0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0}},
@@ -60,7 +57,7 @@ __mpatan(mp_no *x, mp_no *y, int p) {
mp_no mps,mpsm,mpt,mpt1,mpt2,mpt3;
- /* Choose m and initiate mpone, mptwo & mptwoim1 */
+ /* Choose m and initiate mptwo & mptwoim1 */
if (EX>0) m=7;
else if (EX<0) m=0;
else {
@@ -68,8 +65,8 @@ __mpatan(mp_no *x, mp_no *y, int p) {
for (m=6; m>0; m--)
{if (dx>__atan_xm[m].d) break;}
}
- mpone.e = mptwo.e = mptwoim1.e = 1;
- mpone.d[0] = mpone.d[1] = mptwo.d[0] = mptwoim1.d[0] = ONE;
+ mptwo.e = mptwoim1.e = 1;
+ mptwo.d[0] = mptwoim1.d[0] = ONE;
mptwo.d[1] = TWO;
/* Reduce x m times */
diff --git a/sysdeps/ieee754/dbl-64/mpatan2.c b/sysdeps/ieee754/dbl-64/mpatan2.c
index e9c9745..42cb6a7 100644
--- a/sysdeps/ieee754/dbl-64/mpatan2.c
+++ b/sysdeps/ieee754/dbl-64/mpatan2.c
@@ -51,14 +51,10 @@ __mpatan2(mp_no *y, mp_no *x, mp_no *z, int p) {
static const double ZERO = 0.0, ONE = 1.0;
- mp_no mpone = {0,{0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
- 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
- 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0}};
mp_no mpt1,mpt2,mpt3;
if (X[0] <= ZERO) {
- mpone.e = 1; mpone.d[0] = mpone.d[1] = ONE;
__dvd(x,y,&mpt1,p); __mul(&mpt1,&mpt1,&mpt2,p);
if (mpt1.d[0] != ZERO) mpt1.d[0] = ONE;
__add(&mpt2,&mpone,&mpt3,p); __mpsqrt(&mpt3,&mpt2,p);
diff --git a/sysdeps/ieee754/dbl-64/mpexp.c b/sysdeps/ieee754/dbl-64/mpexp.c
index 6b1fcf2..2762ba9 100644
--- a/sysdeps/ieee754/dbl-64/mpexp.c
+++ b/sysdeps/ieee754/dbl-64/mpexp.c
@@ -56,9 +56,6 @@ __mpexp(mp_no *x, mp_no *y, int p) {
{ 0, 0, 0, 0, 0, 0,23,28,33,38,42,47,52,57,62,66, 0, 0},
{ 0, 0, 0, 0, 0, 0, 0, 0,27, 0, 0,39,43,47,51,55,59,63},
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,43,47,50,54}};
- mp_no mpone = {0,{0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
- 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
- 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0}};
mp_no mpk = {0,{0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0}};
@@ -84,7 +81,6 @@ __mpexp(mp_no *x, mp_no *y, int p) {
__mul(x,&mpt1,&mps,p);
/* Evaluate the polynomial. Put result in mpt2 */
- mpone.e=1; mpone.d[0]=ONE; mpone.d[1]=ONE;
mpk.e = 1; mpk.d[0] = ONE; mpk.d[1]=__mpexp_nn[n].d;
__dvd(&mps,&mpk,&mpt1,p);
__add(&mpone,&mpt1,&mpak,p);
diff --git a/sysdeps/ieee754/dbl-64/mplog.c b/sysdeps/ieee754/dbl-64/mplog.c
index 8255e2a..c0606c6 100644
--- a/sysdeps/ieee754/dbl-64/mplog.c
+++ b/sysdeps/ieee754/dbl-64/mplog.c
@@ -40,21 +40,13 @@
void __mpexp(mp_no *, mp_no *, int);
void __mplog(mp_no *x, mp_no *y, int p) {
-#include "mplog.h"
int i,m;
-#if 0
- int j,k,m1,m2,n;
- double a,b;
-#endif
static const int mp[33] = {0,0,0,0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,
4,4,4,4,4,4,4,4,4,4,4,4,4,4};
- mp_no mpone = {0,{0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
- 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
- 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0}};
mp_no mpt1,mpt2;
- /* Choose m and initiate mpone */
- m = mp[p]; mpone.e = 1; mpone.d[0]=mpone.d[1]=ONE;
+ /* Choose m */
+ m = mp[p];
/* Perform m newton iterations to solve for y: exp(y)-x=0. */
/* The iterations formula is: y(n+1)=y(n)+(x*exp(-y(n))-1). */
diff --git a/sysdeps/ieee754/dbl-64/mplog.h b/sysdeps/ieee754/dbl-64/mplog.h
deleted file mode 100644
index b967f52..0000000
--- a/sysdeps/ieee754/dbl-64/mplog.h
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * IBM Accurate Mathematical Library
- * Written by International Business Machines Corp.
- * Copyright (C) 2001 Free Software Foundation, Inc.
- *
- * This program 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.
- *
- * This program 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 this program; if not, see <http://www.gnu.org/licenses/>.
- */
-
-/******************************************************************/
-/* */
-/* MODULE_NAME:mplog.h */
-/* */
-/* common data and variables prototype and definition */
-/******************************************************************/
-
-#ifndef MPLOG_H
-#define MPLOG_H
-
-#ifdef BIG_ENDI
- static const number
-/**/ one = {{0x3ff00000, 0x00000000} }; /* 1 */
-
-#else
-#ifdef LITTLE_ENDI
- static const number
-/**/ one = {{0x00000000, 0x3ff00000} }; /* 1 */
-
-#endif
-#endif
-
-#define ONE one.d
-
-#endif
diff --git a/sysdeps/x86_64/fpu/multiarch/mpa-avx.c b/sysdeps/x86_64/fpu/multiarch/mpa-avx.c
index a92dbed..d3f4d7a 100644
--- a/sysdeps/x86_64/fpu/multiarch/mpa-avx.c
+++ b/sysdeps/x86_64/fpu/multiarch/mpa-avx.c
@@ -7,6 +7,7 @@
#define NO___CPY 1
#define NO___MP_DBL 1
#define NO___ACR 1
+#define NO__CONST 1
#define SECTION __attribute__ ((section (".text.avx")))
#include <sysdeps/ieee754/dbl-64/mpa.c>
diff --git a/sysdeps/x86_64/fpu/multiarch/mpa-fma4.c b/sysdeps/x86_64/fpu/multiarch/mpa-fma4.c
index f8ed8f3..6abb671 100644
--- a/sysdeps/x86_64/fpu/multiarch/mpa-fma4.c
+++ b/sysdeps/x86_64/fpu/multiarch/mpa-fma4.c
@@ -7,6 +7,7 @@
#define NO___CPY 1
#define NO___MP_DBL 1
#define NO___ACR 1
+#define NO__CONST 1
#define SECTION __attribute__ ((section (".text.fma4")))
#include <sysdeps/ieee754/dbl-64/mpa.c>