sysdeps/alpha/reml.S

   1 /* Copyright (C) 2004-2016 Free Software Foundation, Inc.
   2    Contributed by Richard Henderson  <rth@twiddle.net>
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library.  If not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include "div_libc.h"
  20
  21 /* 32-bit signed int remainder.  This is not a normal C function.  Argument
  22    registers are t10 and t11, the result goes in t12.  Only t12 and AT may
  23    be clobbered.
  24
  25    The FPU can handle the division for all input values except zero.
  26    All we have to do is compute the remainder via multiply-and-subtract.
  27
  28    The FPCR save/restore is due to the fact that the EV6 _will_ set FPCR_INE
  29    for cvttq/c even without /sui being set.  It will not, however, properly
  30    raise the exception, so we don't have to worry about FPCR_INED being clear
  31    and so dying by SIGFPE.  */
  32
  33 #ifndef EXTEND
  34 #define EXTEND(S,D)     sextl S, D
  35 #endif
  36
  37         .text
  38         .align  4
  39         .globl  __reml
  40         .type   __reml, @funcnoplt
  41         .usepv  __reml, no
  42
  43         cfi_startproc
  44         cfi_return_column (RA)
  45 __reml:
  46         lda     sp, -FRAME(sp)
  47         cfi_def_cfa_offset (FRAME)
  48         CALL_MCOUNT
  49         stt     $f0, 0(sp)
  50         excb
  51         beq     Y, DIVBYZERO
  52
  53         stt     $f1, 8(sp)
  54         stt     $f2, 16(sp)
  55         cfi_rel_offset ($f0, 0)
  56         cfi_rel_offset ($f1, 8)
  57         cfi_rel_offset ($f2, 16)
  58         mf_fpcr $f2
  59
  60         EXTEND  (X, RV)
  61         EXTEND  (Y, AT)
  62         _ITOFT2 RV, $f0, 24, AT, $f1, 32
  63         cvtqt   $f0, $f0
  64         cvtqt   $f1, $f1
  65         divt/c  $f0, $f1, $f0
  66         cvttq/c $f0, $f0
  67         excb
  68         mt_fpcr $f2
  69         _FTOIT  $f0, RV, 24
  70
  71         ldt     $f0, 0(sp)
  72         mull    RV, Y, RV
  73         ldt     $f1, 8(sp)
  74         ldt     $f2, 16(sp)
  75         lda     sp, FRAME(sp)
  76         cfi_restore ($f0)
  77         cfi_restore ($f1)
  78         cfi_restore ($f2)
  79         cfi_def_cfa_offset (0)
  80         subl    X, RV, RV
  81         ret     $31, (RA), 1
  82
  83         cfi_endproc
  84         .size   __reml, .-__reml
  85
  86         DO_DIVBYZERO