1  /* Copyright (C) 1989-2023 Free Software Foundation, Inc.
       2  
       3  This file is part of GCC.
       4  
       5  GCC is free software; you can redistribute it and/or modify it under
       6  the terms of the GNU General Public License as published by the Free
       7  Software Foundation; either version 3, or (at your option) any later
       8  version.
       9  
      10  GCC is distributed in the hope that it will be useful, but WITHOUT ANY
      11  WARRANTY; without even the implied warranty of MERCHANTABILITY or
      12  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      13  for more details.
      14  
      15  Under Section 7 of GPL version 3, you are granted additional
      16  permissions described in the GCC Runtime Library Exception, version
      17  3.1, as published by the Free Software Foundation.
      18  
      19  You should have received a copy of the GNU General Public License and
      20  a copy of the GCC Runtime Library Exception along with this program;
      21  see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      22  <http://www.gnu.org/licenses/>.  */
      23  
      24  #include "soft-fp.h"
      25  #include "quad-float128.h"
      26  
      27  /* __powikf3 can be compiled 3 different ways:
      28  
      29     1) If the assembler does not have support for the IEEE 128-bit insns
      30     (xsaddqp, etc.) it is just compiled as __powikf2.
      31  
      32     2) If the assembler has IEEE 128-bit floating point support, and __powikf2
      33     is not previously defined, it is defined as __powikf2_sw.
      34  
      35     3) If the assembler has IEEE 128-bit floating point support, and __powikf2
      36     is included by _powikf2-hw.c, which defines __powikf2 as __powikf2_hw.  The
      37     __powikf2_hw.c is compiled with -mcpu=power9 and it automatically uses the
      38     IEEE 128-bit instructions.
      39  
      40     For #2/#3, float128-ifunc.c defines an ifunc function for __powikf2, that
      41     will use the software version on power7/power8 systems, and the hardware
      42     version on power9 systems.
      43  
      44     The code is cloned from the code in libgcc2.c (which handles the standard
      45     SF, DF, TF, and XF types).  */
      46  
      47  #if defined(FLOAT128_HW_INSNS) && !defined(__powikf2)
      48  #define __powikf2 __powikf2_sw
      49  #endif
      50  
      51  TFtype
      52  __powikf2 (TFtype x, SItype_ppc m)
      53  {
      54    unsigned int n = m < 0 ? -m : m;
      55    TFtype y = n % 2 ? x : 1;
      56    while (n >>= 1)
      57      {
      58        x = x * x;
      59        if (n % 2)
      60  	y = y * x;
      61      }
      62    return m < 0 ? 1/y : y;
      63  }