libphobos/libdruntime/config/mips/switchcontext.S

   1 /* MIPS support code for fibers and multithreading.
   2    Copyright (C) 2019-2020 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 Under Section 7 of GPL version 3, you are granted additional
  17 permissions described in the GCC Runtime Library Exception, version
  18 3.1, as published by the Free Software Foundation.
  19
  20 You should have received a copy of the GNU General Public License and
  21 a copy of the GCC Runtime Library Exception along with this program;
  22 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 <http://www.gnu.org/licenses/>.  */
  24
  25 #include "../common/threadasm.S"
  26
  27 #if _MIPS_SIM == _ABIO32
  28
  29 /**
  30  * Performs a context switch.
  31  *
  32  * $a0 - void** - ptr to old stack pointer
  33  * $a1 - void*  - new stack pointer
  34  *
  35  */
  36     .text
  37     .globl fiber_switchContext
  38     .align 2
  39     .ent fiber_switchContext,0
  40 fiber_switchContext:
  41     .cfi_startproc
  42     addiu $sp, $sp, -(10 * 4)
  43
  44     // fp regs and return address are stored below the stack
  45     // because we don't want the GC to scan them.
  46
  47 #ifdef __mips_hard_float
  48 #define ALIGN8(val) (val + (-val & 7))
  49 #define BELOW (ALIGN8(6 * 8 + 4))
  50     sdc1 $f20, (0 * 8 - BELOW)($sp)
  51     sdc1 $f22, (1 * 8 - BELOW)($sp)
  52     sdc1 $f24, (2 * 8 - BELOW)($sp)
  53     sdc1 $f26, (3 * 8 - BELOW)($sp)
  54     sdc1 $f28, (4 * 8 - BELOW)($sp)
  55     sdc1 $f30, (5 * 8 - BELOW)($sp)
  56 #endif
  57     sw $ra, -4($sp)
  58
  59     sw $s0, (0 * 4)($sp)
  60     sw $s1, (1 * 4)($sp)
  61     sw $s2, (2 * 4)($sp)
  62     sw $s3, (3 * 4)($sp)
  63     sw $s4, (4 * 4)($sp)
  64     sw $s5, (5 * 4)($sp)
  65     sw $s6, (6 * 4)($sp)
  66     sw $s7, (7 * 4)($sp)
  67     sw $s8, (8 * 4)($sp)
  68     sw $gp, (9 * 4)($sp)
  69
  70     // swap stack pointer
  71     sw $sp, 0($a0)
  72     move $sp, $a1
  73
  74 #ifdef __mips_hard_float
  75     ldc1 $f20, (0 * 8 - BELOW)($sp)
  76     ldc1 $f22, (1 * 8 - BELOW)($sp)
  77     ldc1 $f24, (2 * 8 - BELOW)($sp)
  78     ldc1 $f26, (3 * 8 - BELOW)($sp)
  79     ldc1 $f28, (4 * 8 - BELOW)($sp)
  80     ldc1 $f30, (5 * 8 - BELOW)($sp)
  81 #endif
  82     lw $ra, -4($sp)
  83
  84     lw $s0, (0 * 4)($sp)
  85     lw $s1, (1 * 4)($sp)
  86     lw $s2, (2 * 4)($sp)
  87     lw $s3, (3 * 4)($sp)
  88     lw $s4, (4 * 4)($sp)
  89     lw $s5, (5 * 4)($sp)
  90     lw $s6, (6 * 4)($sp)
  91     lw $s7, (7 * 4)($sp)
  92     lw $s8, (8 * 4)($sp)
  93     lw $gp, (9 * 4)($sp)
  94
  95     addiu $sp, $sp, (10 * 4)
  96
  97     jr $ra // return
  98     .cfi_endproc
  99     .end fiber_switchContext
 100     .size fiber_switchContext,.-fiber_switchContext
 101
 102 #endif