libgcc/config/msp430/lib2shift.c

   1 /* Shift functions for the GCC support library for the MSP430
   2    Copyright (C) 2011-2024 Free Software Foundation, Inc.
   3    Contributed by Red Hat.
   4
   5    This file is part of GCC.
   6
   7    GCC is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3, or (at your option)
  10    any later version.
  11
  12    GCC is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    Under Section 7 of GPL version 3, you are granted additional
  18    permissions described in the GCC Runtime Library Exception, version
  19    3.1, as published by the Free Software Foundation.
  20
  21    You should have received a copy of the GNU General Public License and
  22    a copy of the GCC Runtime Library Exception along with this program;
  23    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24    <http://www.gnu.org/licenses/>.  */
  25 \f
  26 typedef          int  sint32_type   __attribute__ ((mode (SI)));
  27 typedef unsigned int  uint32_type   __attribute__ ((mode (SI)));
  28 typedef          int  sint16_type   __attribute__ ((mode (HI)));
  29 typedef unsigned int  uint16_type   __attribute__ ((mode (HI)));
  30
  31 uint32_type __ashlsi3 (uint32_type, signed char);
  32 sint32_type __ashrsi3 (sint32_type, signed char);
  33 int         __clrsbhi2 (sint16_type);
  34 extern int  __clrsbsi2 (sint32_type);
  35
  36 typedef struct
  37 {
  38   union
  39   {
  40     uint32_type u;
  41     uint16_type h[2];
  42   } u;
  43 } dd;
  44
  45 uint32_type
  46 __ashlsi3 (uint32_type in, signed char bit)
  47 {
  48   uint16_type h, l;
  49   dd d;
  50
  51   if (bit > 32)
  52     return 0;
  53   if (bit < 0)
  54     return in;
  55
  56   d.u.u = in;
  57   h = d.u.h[1];
  58   l = d.u.h[0];
  59
  60   if (bit > 15)
  61     {
  62       h = l;
  63       l = 0;
  64       bit -= 16;
  65     }
  66
  67   while (bit)
  68     {
  69       h = (h << 1) | (l >> 15);
  70       l <<= 1;
  71       bit --;
  72     }
  73
  74   d.u.h[1] = h;
  75   d.u.h[0] = l;
  76   return d.u.u;
  77 }
  78
  79 sint32_type
  80 __ashrsi3 (sint32_type in, signed char bit)
  81 {
  82   sint16_type h;
  83   uint16_type l;
  84   dd d;
  85
  86   if (bit > 32)
  87     return 0;
  88   if (bit < 0)
  89     return in;
  90
  91   d.u.u = in;
  92   h = d.u.h[1];
  93   l = d.u.h[0];
  94
  95   while (bit)
  96     {
  97       l = (h << 15) | (l >> 1);
  98       h >>= 1;
  99       bit --;
 100     }
 101
 102   d.u.h[1] = h;
 103   d.u.h[0] = l;
 104   return d.u.u;
 105 }
 106
 107 int
 108 __clrsbhi2 (sint16_type x)
 109 {
 110   if (x == 0)
 111     return 15;
 112   return __clrsbsi2 ((sint32_type) x) - 16;
 113 }