ports/sysdeps/mips/__longjmp.c

   1 /* Copyright (C) 1992-2013 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Brendan Kehoe (brendan@zen.org).
   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 <setjmp.h>
  20 #include <stdlib.h>
  21
  22 #ifndef __GNUC__
  23   #error This file uses GNU C extensions; you must compile with GCC.
  24 #endif
  25
  26 void
  27 __longjmp (env_arg, val_arg)
  28      __jmp_buf env_arg;
  29      int val_arg;
  30 {
  31   /* gcc 1.39.19 miscompiled the longjmp routine (as it did setjmp before
  32      the hack around it); force it to use $a1 for the longjmp value.
  33      Without this it saves $a1 in a register which gets clobbered
  34      along the way.  */
  35   register struct __jmp_buf_internal_tag *env asm ("a0");
  36   register int val asm ("a1");
  37 #ifdef CHECK_SP
  38   register long sp asm ("$29");
  39   CHECK_SP (env[0].__sp, sp, long);
  40 #endif
  41
  42 #ifdef __mips_hard_float
  43   /* Pull back the floating point callee-saved registers.  */
  44   asm volatile ("l.d $f20, %0" : : "m" (env[0].__fpregs[0]));
  45   asm volatile ("l.d $f22, %0" : : "m" (env[0].__fpregs[1]));
  46   asm volatile ("l.d $f24, %0" : : "m" (env[0].__fpregs[2]));
  47   asm volatile ("l.d $f26, %0" : : "m" (env[0].__fpregs[3]));
  48   asm volatile ("l.d $f28, %0" : : "m" (env[0].__fpregs[4]));
  49   asm volatile ("l.d $f30, %0" : : "m" (env[0].__fpregs[5]));
  50
  51   /* Get and reconstruct the floating point csr.  */
  52   asm volatile ("lw $2, %0" : : "m" (env[0].__fpc_csr));
  53   asm volatile ("ctc1 $2, $31");
  54 #endif
  55
  56   /* Get the GP. */
  57   asm volatile ("lw $gp, %0" : : "m" (env[0].__gp));
  58
  59   /* Get the callee-saved registers.  */
  60   asm volatile ("lw $16, %0" : : "m" (env[0].__regs[0]));
  61   asm volatile ("lw $17, %0" : : "m" (env[0].__regs[1]));
  62   asm volatile ("lw $18, %0" : : "m" (env[0].__regs[2]));
  63   asm volatile ("lw $19, %0" : : "m" (env[0].__regs[3]));
  64   asm volatile ("lw $20, %0" : : "m" (env[0].__regs[4]));
  65   asm volatile ("lw $21, %0" : : "m" (env[0].__regs[5]));
  66   asm volatile ("lw $22, %0" : : "m" (env[0].__regs[6]));
  67   asm volatile ("lw $23, %0" : : "m" (env[0].__regs[7]));
  68
  69   /* Get the PC.  */
  70   asm volatile ("lw $25, %0" : : "m" (env[0].__pc));
  71
  72   /* Restore the stack pointer and the FP.  They have to be restored
  73      last and in a single asm as gcc, depending on options used, may
  74      use either of them to access env.  */
  75   asm volatile ("lw $29, %0\n\t"
  76                 "lw $30, %1\n\t" : : "m" (env[0].__sp), "m" (env[0].__fp));
  77
  78 /* Give setjmp 1 if given a 0, or what they gave us if non-zero.  */
  79   if (val == 0)
  80     asm volatile ("li $2, 1");
  81   else
  82     asm volatile ("move $2, %0" : : "r" (val));
  83
  84   asm volatile ("jr $25");
  85
  86   /* Avoid `volatile function does return' warnings.  */
  87   for (;;);
  88 }