gcc/libgcc/config/rs6000/_powikf2.c

64 lines
2.1 KiB
C

/* Copyright (C) 1989-2020 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC 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 General Public License
for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#include "soft-fp.h"
#include "quad-float128.h"
/* __powikf3 can be compiled 3 different ways:
1) If the assembler does not have support for the IEEE 128-bit insns
(xsaddqp, etc.) it is just compiled as __powikf2.
2) If the assembler has IEEE 128-bit floating point support, and __powikf2
is not previously defined, it is defined as __powikf2_sw.
3) If the assembler has IEEE 128-bit floating point support, and __powikf2
is included by _powikf2-hw.c, which defines __powikf2 as __powikf2_hw. The
__powikf2_hw.c is compiled with -mcpu=power9 and it automatically uses the
IEEE 128-bit instructions.
For #2/#3, float128-ifunc.c defines an ifunc function for __powikf2, that
will use the software version on power7/power8 systems, and the hardware
version on power9 systems.
The code is cloned from the code in libgcc2.c (which handles the standard
SF, DF, TF, and XF types). */
#if defined(FLOAT128_HW_INSNS) && !defined(__powikf2)
#define __powikf2 __powikf2_sw
#endif
TFtype
__powikf2 (TFtype x, SItype_ppc m)
{
unsigned int n = m < 0 ? -m : m;
TFtype y = n % 2 ? x : 1;
while (n >>= 1)
{
x = x * x;
if (n % 2)
y = y * x;
}
return m < 0 ? 1/y : y;
}