platform_bionic/libm/fake_long_double.c
Adhemerval Zanella f6b101d3ec Use double-precision routines from arm-optimized-routines
This patch ues exp, exp2, log, log2, and pow from arm optimized
routines.  For pow on x86_64, although slight slower it simplifies
the code required on both bionic and arm-optimized-routines (so
there is no need to select and export the symbol based on
architecture).

Performance-wise the improvements are:

  x86_64    throughput    latency
  exp            1.16x      1.16x
  log            1.08x      0.95x
  exp2           1.27x      1.55x
  log2           1.40x      1.43x
  pow            0.77x      0.89x *

  * I tried to check if AVX2/FMA but without success.

  aarch64   throughput     latency
  exp            2.33x      2.16x
  exp2           1.99x      1.50x
  log            1.79x      1.43x
  log2           2.15x      1.80x
  pow            3.81x      3.07x

Test: ran bionic tests on static mode.
Change-Id: Ib16bf3280c5329fd257a3b3f0b6c4f2f3cb34deb
2018-08-09 11:22:24 -03:00

56 lines
2.5 KiB
C

/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define _GNU_SOURCE
#include <float.h>
#include <math.h>
#if !defined(__LP64__)
// The BSD "long double" functions are broken when sizeof(long double) == sizeof(double).
// Android works around those cases by replacing the broken functions with our own trivial stubs
// that call the regular "double" function.
long double copysignl(long double a1, long double a2) { return copysign(a1, a2); }
long double fmaxl(long double a1, long double a2) { return fmax(a1, a2); }
long double fmodl(long double a1, long double a2) { return fmod(a1, a2); }
long double fminl(long double a1, long double a2) { return fmin(a1, a2); }
int ilogbl(long double a1) { return ilogb(a1); }
long long llrintl(long double a1) { return llrint(a1); }
#if !defined(__i386__) // x86 has an assembler lrint/lrintl.
long lrintl(long double a1) { return lrint(a1); }
#endif
long long llroundl(long double a1) { return llround(a1); }
long lroundl(long double a1) { return lround(a1); }
long double modfl(long double a1, long double* a2) { double i; double f = modf(a1, &i); *a2 = i; return f; }
float nexttowardf(float a1, long double a2) { return nextafterf(a1, (float) a2); }
long double powl(long double x, long double y) { return pow(x, y); }
long double roundl(long double a1) { return round(a1); }
void sincosl(long double x, long double* s, long double* c) { sincos(x, (double*) s, (double*) c); }
#endif // __LP64__
// FreeBSD doesn't have an ld128 implementations of tgammal, so both LP32 and LP64 need this.
long double tgammal(long double x) { return tgamma(x); }
// external/arm-optimized-routines does not provide the long double
// wrappers for the routines it implements.
#if (LDBL_MANT_DIG == 53)
long double expl(long double x) { return exp(x); }
long double exp2l(long double x) { return exp2(x); }
long double logl(long double x) { return log(x); }
long double log2l(long double x) { return log2(x); }
#endif