Implementations of cexpl()

The change implements cexpl() for both ld80 and ld128 architectures.
Testing was done on x86_64 and aarch64 systems.

Along the way sincos[fl]() use an optimization that reduces the argument
to being done one rather than twice.  This optimization actually pointed
to a bug in the ld128 version of sincosl(), which is now fixed.  In
addition, the minmax polynomial coefficients for sincosl() have been
updated.

A concise log of the file-by-file changes follows.

* include/complex.h:
  . Add a prototype for cexpl().

* lib/msun/Makefile:
  . Add s_cexpl.c to the build.
  . Setup a link for cexpl.3 to cexp.3.

* lib/msun/Symbol.map:
  . Expose cexpl symbol in libm shared library.

* lib/msun/ld128/s_cexpl.c:
  * Implementation of cexpl() for 128-bit long double architectures.
    Tested on an aarch64 system.

* lib/msun/ld80/s_cexpl.c:
  * Implementation of cexpl() for Intel 80-bit long double.

* lib/msun/man/cexp.3:
  . Document cexpl().

* lib/msun/man/complex.3:
  . Add a BUGS section about cpow[fl].

* lib/msun/src/s_cexp.c:
  . Include float.h for weak references on 53-bit long double targets.
  . Use sincos() to reduce argument reduction cost.

* lib/msun/src/s_cexpf.c:
  . Use sincosf() to reduce argument reduction cost.

* lib/msun/src/k_sincosl.h:
  . Catch up with the new minmax polynomial coefficients for the kernel for
    the 128-bit cosl() implementation.
  . BUG FIX: *cs was used where *sn should have been.  This means that sinl()
    was no computed correctly when iy != 0.

* lib/msun/src/s_cosl.c:
  . Include fpmath.h to get access to IEEEl2bits.
  . Replace M_PI_4 with pio4,  a 64-bit or 113-bit approximation for pi / 4.

PR:	216862
MFC after:	1 week
This commit is contained in:
Steve Kargl 2021-11-05 04:04:01 +02:00 committed by Konstantin Belousov
parent 8b57ee7e01
commit 046e2d5db1
11 changed files with 265 additions and 31 deletions

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@ -98,6 +98,8 @@ double complex ccosh(double complex);
float complex ccoshf(float complex);
double complex cexp(double complex);
float complex cexpf(float complex);
long double complex
cexpl(long double complex);
double cimag(double complex) __pure2;
float cimagf(float complex) __pure2;
long double cimagl(long double complex) __pure2;

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@ -117,7 +117,7 @@ COMMON_SRCS+= catrigl.c \
e_lgammal.c e_lgammal_r.c e_powl.c \
e_remainderl.c e_sinhl.c e_sqrtl.c \
invtrig.c k_cosl.c k_sinl.c k_tanl.c \
s_asinhl.c s_atanl.c s_cbrtl.c s_ceill.c \
s_asinhl.c s_atanl.c s_cbrtl.c s_ceill.c s_cexpl.c \
s_clogl.c s_cosl.c s_cospil.c s_cprojl.c \
s_csqrtl.c s_erfl.c s_exp2l.c s_expl.c s_floorl.c s_fmal.c \
s_fmaxl.c s_fminl.c s_frexpl.c s_logbl.c s_logl.c s_nanl.c \
@ -189,7 +189,7 @@ MLINKS+=ccos.3 ccosf.3 ccos.3 csin.3 ccos.3 csinf.3 ccos.3 ctan.3 ccos.3 ctanf.3
MLINKS+=ccosh.3 ccoshf.3 ccosh.3 csinh.3 ccosh.3 csinhf.3 \
ccosh.3 ctanh.3 ccosh.3 ctanhf.3
MLINKS+=ceil.3 ceilf.3 ceil.3 ceill.3
MLINKS+=cexp.3 cexpf.3
MLINKS+=cexp.3 cexpf.3 cexp.3 cexpl.3
MLINKS+=cimag.3 cimagf.3 cimag.3 cimagl.3 \
cimag.3 conj.3 cimag.3 conjf.3 cimag.3 conjl.3 \
cimag.3 cproj.3 cimag.3 cprojf.3 cimag.3 cprojl.3 \

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@ -307,6 +307,7 @@ FBSD_1.5 {
/* First added in 14.0-CURRENT */
FBSD_1.7 {
cexpl;
cospi;
cospif;
cospil;

94
lib/msun/ld128/s_cexpl.c Normal file
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@ -0,0 +1,94 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2019 Steven G. Kargl <kargl@FreeBSD.ORG>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <complex.h>
#include <float.h>
#include <math.h>
#include "fpmath.h"
#include "math_private.h"
#include "k_expl.h"
/* XXX cexpl() should be converted to use bits likeo src/s_cexp.c. */
static const long double
cexp_ovfl = 2.27892930024498818830197576893019292e+04L,
exp_ovfl = 1.13565234062941439494919310779707649e+04L;
long double complex
cexpl(long double complex z)
{
long double c, exp_x, s, x, y;
x = creall(z);
y = cimagl(z);
/* cexp(x + I 0) = exp(x) + I 0 */
if (y == 0)
return (CMPLXL(expl(x), y));
/* cexp(0 + I y) = cos(y) + I sin(y) */
if (x == 0) {
sincosl(y, &s, &c);
return (CMPLXL(c, s));
}
if (!isfinite(y)) {
if (isfinite(x) || isnan(x)) {
/* cexp(finite|NaN +- I Inf|NaN) = NaN + I NaN */
return (CMPLXL(y - y, y - y));
} else if (isinf(x) && copysignl(1.L, x) < 0) {
/* cexp(-Inf +- I Inf|NaN) = 0 + I 0 */
return (CMPLXL(0.0, 0.0));
} else {
/* cexp(+Inf +- I Inf|NaN) = Inf + I NaN */
return (CMPLXL(x, y - y));
}
}
if (x > exp_ovfl && x < cexp_ovfl) {
/*
* x is between exp_ovfl and cexp_ovfl, so we must scale to
* avoid overflow in exp(x).
*/
return (__ldexp_cexpl(z, 0));
} else {
/*
* Cases covered here:
* - x < exp_ovfl and exp(x) won't overflow (common case)
* - x > cexp_ovfl, so exp(x) * s overflows for all s > 0
* - x = +-Inf (generated by exp())
* - x = NaN (spurious inexact exception from y)
*/
exp_x = expl(x);
sincosl(y, &s, &c);
return (CMPLXL(exp_x * c, exp_x * s));
}
}

107
lib/msun/ld80/s_cexpl.c Normal file
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@ -0,0 +1,107 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2011 David Schultz <das@FreeBSD.ORG>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* src/s_cexp.c converted to long double complex by Steven G. Kargl
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <complex.h>
#include <float.h>
#ifdef __i386__
#include <ieeefp.h>
#endif
#include "fpmath.h"
#include "math.h"
#include "math_private.h"
#include "k_expl.h"
long double complex
cexpl (long double complex z)
{
long double c, exp_x, s, x, y;
uint64_t lx, ly;
uint16_t hx, hy;
ENTERI();
x = creall(z);
y = cimagl(z);
EXTRACT_LDBL80_WORDS(hy, ly, y);
hy &= 0x7fff;
/* cexp(x + I 0) = exp(x) + I 0 */
if ((hy | ly) == 0)
RETURNI(CMPLXL(expl(x), y));
EXTRACT_LDBL80_WORDS(hx, lx, x);
/* cexp(0 + I y) = cos(y) + I sin(y) */
if (((hx & 0x7fff) | lx) == 0) {
sincosl(y, &s, &c);
RETURNI(CMPLXL(c, s));
}
if (hy >= 0x7fff) {
if ((hx & 0x7fff) < 0x7fff || ((hx & 0x7fff) == 0x7fff &&
(lx & 0x7fffffffffffffffULL) != 0)) {
/* cexp(finite|NaN +- I Inf|NaN) = NaN + I NaN */
RETURNI(CMPLXL(y - y, y - y));
} else if (hx & 0x8000) {
/* cexp(-Inf +- I Inf|NaN) = 0 + I 0 */
RETURNI(CMPLXL(0.0, 0.0));
} else {
/* cexp(+Inf +- I Inf|NaN) = Inf + I NaN */
RETURNI(CMPLXL(x, y - y));
}
}
/*
* exp_ovfl = 11356.5234062941439497
* cexp_ovfl = 22755.3287906024445633
*/
if ((hx == 0x400c && lx > 0xb17217f7d1cf79acULL) ||
(hx == 0x400d && lx < 0xb1c6a8573de9768cULL)) {
/*
* x is between exp_ovfl and cexp_ovfl, so we must scale to
* avoid overflow in exp(x).
*/
RETURNI(__ldexp_cexpl(z, 0));
} else {
/*
* Cases covered here:
* - x < exp_ovfl and exp(x) won't overflow (common case)
* - x > cexp_ovfl, so exp(x) * s overflows for all s > 0
* - x = +-Inf (generated by exp())
* - x = NaN (spurious inexact exception from y)
*/
exp_x = expl(x);
sincosl(y, &s, &c);
RETURNI(CMPLXL(exp_x * c, exp_x * s));
}
}

View File

@ -24,12 +24,13 @@
.\"
.\" $FreeBSD$
.\"
.Dd March 6, 2011
.Dd November 3, 2021
.Dt CEXP 3
.Os
.Sh NAME
.Nm cexp ,
.Nm cexpf
.Nm cexpf ,
.Nm cexpl
.Nd complex exponential functions
.Sh LIBRARY
.Lb libm
@ -39,11 +40,14 @@
.Fn cexp "double complex z"
.Ft float complex
.Fn cexpf "float complex z"
.Ft long double complex
.Fn cexpl "long double complex z"
.Sh DESCRIPTION
The
.Fn cexp
.Fn cexp ,
.Fn cexpf ,
and
.Fn cexpf
.Fn cexpl
functions compute the complex exponential of
.Fa z ,
also known as
@ -106,8 +110,9 @@ is not finite, the sign of the result is indeterminate.
.Xr math 3
.Sh STANDARDS
The
.Fn cexp
.Fn cexp ,
.Fn cexpf ,
and
.Fn cexpf
.Fn cexpl
functions conform to
.St -isoC-99 .

View File

@ -24,7 +24,7 @@
.\"
.\" $FreeBSD$
.\"
.Dd June 19, 2018
.Dd November 3, 2021
.Dt COMPLEX 3
.Os
.Sh NAME
@ -121,3 +121,9 @@ The
.In complex.h
functions described here conform to
.St -isoC-99 .
.Sh BUGS
The power functions,
.Fn cpowf, cpow ,
and
.Fn cpowl ,
are implemented, but the code was neither reviewed nor tested.

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@ -76,13 +76,6 @@ __kernel_sincosl(long double x, long double y, int iy, long double *sn,
#elif LDBL_MANT_DIG == 113 /* ld128 version of k_sincosl.c. */
static const long double
C1 = 0.04166666666666666666666666666666658424671L,
C2 = -0.001388888888888888888888888888863490893732L,
C3 = 0.00002480158730158730158730158600795304914210L,
C4 = -0.2755731922398589065255474947078934284324e-6L,
C5 = 0.2087675698786809897659225313136400793948e-8L,
C6 = -0.1147074559772972315817149986812031204775e-10L,
C7 = 0.4779477332386808976875457937252120293400e-13L,
S1 = -0.16666666666666666666666666666666666606732416116558L,
S2 = 0.0083333333333333333333333333333331135404851288270047L,
S3 = -0.00019841269841269841269841269839935785325638310428717L,
@ -93,15 +86,25 @@ S7 = -0.76471637318198151807063387954939213287488216303768e-12L,
S8 = 0.28114572543451292625024967174638477283187397621303e-14L;
static const double
C8 = -0.1561920696721507929516718307820958119868e-15,
C9 = 0.4110317413744594971475941557607804508039e-18,
C10 = -0.8896592467191938803288521958313920156409e-21,
C11 = 0.1601061435794535138244346256065192782581e-23,
S9 = -0.82206352458348947812512122163446202498005154296863e-17,
S10 = 0.19572940011906109418080609928334380560135358385256e-19,
S11 = -0.38680813379701966970673724299207480965452616911420e-22,
S12 = 0.64038150078671872796678569586315881020659912139412e-25;
static const long double
C1 = 4.16666666666666666666666666666666667e-02L,
C2 = -1.38888888888888888888888888888888834e-03L,
C3 = 2.48015873015873015873015873015446795e-05L,
C4 = -2.75573192239858906525573190949988493e-07L,
C5 = 2.08767569878680989792098886701451072e-09L,
C6 = -1.14707455977297247136657111139971865e-11L,
C7 = 4.77947733238738518870113294139830239e-14L,
C8 = -1.56192069685858079920640872925306403e-16L,
C9 = 4.11031762320473354032038893429515732e-19L,
C10= -8.89679121027589608738005163931958096e-22L,
C11= 1.61171797801314301767074036661901531e-24L,
C12= -2.46748624357670948912574279501044295e-27L;
static inline void
__kernel_sincosl(long double x, long double y, int iy, long double *sn,
long double *cs)
@ -120,12 +123,12 @@ __kernel_sincosl(long double x, long double y, int iy, long double *sn,
if (iy == 0)
*sn = x + v * (S1 + z * r);
else
*cs = x - ((z * (y / 2 - v * r) - y) - v * S1);
*sn = x - ((z * (y / 2 - v * r) - y) - v * S1);
hz = z / 2;
w = 1 - hz;
r = z * (C1 + z * (C2 + z * (C3 + z * (C4 + z * (C5 + z * (C6 +
z * (C7 + z * (C8 + z * (C9 + z * (C10 + z * C11))))))))));
z * (C7 + z * (C8 + z * (C9 + z * (C10 + z * (C11+z*C12)))))))))));
*cs = w + (((1 - w) - hz) + (z * r - x * y));
}

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@ -30,6 +30,7 @@
__FBSDID("$FreeBSD$");
#include <complex.h>
#include <float.h>
#include <math.h>
#include "math_private.h"
@ -41,7 +42,7 @@ cexp_ovfl = 0x4096b8e4; /* (MAX_EXP - MIN_DENORM_EXP) * ln2 */
double complex
cexp(double complex z)
{
double x, y, exp_x;
double c, exp_x, s, x, y;
uint32_t hx, hy, lx, ly;
x = creal(z);
@ -55,8 +56,10 @@ cexp(double complex z)
return (CMPLX(exp(x), y));
EXTRACT_WORDS(hx, lx, x);
/* cexp(0 + I y) = cos(y) + I sin(y) */
if (((hx & 0x7fffffff) | lx) == 0)
return (CMPLX(cos(y), sin(y)));
if (((hx & 0x7fffffff) | lx) == 0) {
sincos(y, &s, &c);
return (CMPLX(c, s));
}
if (hy >= 0x7ff00000) {
if (lx != 0 || (hx & 0x7fffffff) != 0x7ff00000) {
@ -86,6 +89,11 @@ cexp(double complex z)
* - x = NaN (spurious inexact exception from y)
*/
exp_x = exp(x);
return (CMPLX(exp_x * cos(y), exp_x * sin(y)));
sincos(y, &s, &c);
return (CMPLX(exp_x * c, exp_x * s));
}
}
#if (LDBL_MANT_DIG == 53)
__weak_reference(cexp, cexpl);
#endif

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@ -41,7 +41,7 @@ cexp_ovfl = 0x43400074; /* (MAX_EXP - MIN_DENORM_EXP) * ln2 */
float complex
cexpf(float complex z)
{
float x, y, exp_x;
float c, exp_x, s, x, y;
uint32_t hx, hy;
x = crealf(z);
@ -55,8 +55,10 @@ cexpf(float complex z)
return (CMPLXF(expf(x), y));
GET_FLOAT_WORD(hx, x);
/* cexp(0 + I y) = cos(y) + I sin(y) */
if ((hx & 0x7fffffff) == 0)
return (CMPLXF(cosf(y), sinf(y)));
if ((hx & 0x7fffffff) == 0) {
sincosf(y, &s, &c);
return (CMPLXF(c, s));
}
if (hy >= 0x7f800000) {
if ((hx & 0x7fffffff) != 0x7f800000) {
@ -86,6 +88,7 @@ cexpf(float complex z)
* - x = NaN (spurious inexact exception from y)
*/
exp_x = expf(x);
return (CMPLXF(exp_x * cosf(y), exp_x * sinf(y)));
sincosf(y, &s, &c);
return (CMPLXF(exp_x * c, exp_x * s));
}
}

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@ -39,12 +39,17 @@ __FBSDID("$FreeBSD$");
#include <ieeefp.h>
#endif
#include "fpmath.h"
#include "math.h"
#include "math_private.h"
#if LDBL_MANT_DIG == 64
#include "../ld80/e_rem_pio2l.h"
static const union IEEEl2bits
pio4u = LD80C(0xc90fdaa22168c235, -00001, 7.85398163397448309628e-01L);
#define pio4 (pio4u.e)
#elif LDBL_MANT_DIG == 113
#include "../ld128/e_rem_pio2l.h"
long double pio4 = 7.85398163397448309615660845819875721e-1L;
#else
#error "Unsupported long double format"
#endif
@ -71,7 +76,7 @@ cosl(long double x)
ENTERI();
/* Optimize the case where x is already within range. */
if (z.e < M_PI_4)
if (z.e < pio4)
RETURNI(__kernel_cosl(z.e, 0));
e0 = __ieee754_rem_pio2l(x, y);