sysdeps/mips/__longjmp.c

   1 /* Copyright (C) 1992-2019 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 static void __attribute__ ((nomips16))
  27 ____longjmp (__jmp_buf env_arg, int val_arg)
  28 {
  29   /* gcc 1.39.19 miscompiled the longjmp routine (as it did setjmp before
  30      the hack around it); force it to use $a1 for the longjmp value.
  31      Without this it saves $a1 in a register which gets clobbered
  32      along the way.  */
  33   register struct __jmp_buf_internal_tag *env asm ("a0");
  34   register int val asm ("a1");
  35 #ifdef CHECK_SP
  36   register long sp asm ("$29");
  37   CHECK_SP (env[0].__sp, sp, long);
  38 #endif
  39
  40 #ifdef __mips_hard_float
  41   /* Pull back the floating point callee-saved registers.  */
  42   asm volatile ("l.d $f20, %0" : : "m" (env[0].__fpregs[0]));
  43   asm volatile ("l.d $f22, %0" : : "m" (env[0].__fpregs[1]));
  44   asm volatile ("l.d $f24, %0" : : "m" (env[0].__fpregs[2]));
  45   asm volatile ("l.d $f26, %0" : : "m" (env[0].__fpregs[3]));
  46   asm volatile ("l.d $f28, %0" : : "m" (env[0].__fpregs[4]));
  47   asm volatile ("l.d $f30, %0" : : "m" (env[0].__fpregs[5]));
  48 #endif
  49
  50   /* Get the GP. */
  51   asm volatile ("lw $gp, %0" : : "m" (env[0].__gp));
  52
  53   /* Get the callee-saved registers.  */
  54   asm volatile ("lw $16, %0" : : "m" (env[0].__regs[0]));
  55   asm volatile ("lw $17, %0" : : "m" (env[0].__regs[1]));
  56   asm volatile ("lw $18, %0" : : "m" (env[0].__regs[2]));
  57   asm volatile ("lw $19, %0" : : "m" (env[0].__regs[3]));
  58   asm volatile ("lw $20, %0" : : "m" (env[0].__regs[4]));
  59   asm volatile ("lw $21, %0" : : "m" (env[0].__regs[5]));
  60   asm volatile ("lw $22, %0" : : "m" (env[0].__regs[6]));
  61   asm volatile ("lw $23, %0" : : "m" (env[0].__regs[7]));
  62
  63   /* Get the PC.  */
  64   asm volatile ("lw $25, %0" : : "m" (env[0].__pc));
  65
  66   /* Restore the stack pointer and the FP.  They have to be restored
  67      last and in a single asm as gcc, depending on options used, may
  68      use either of them to access env.  */
  69   asm volatile ("lw $29, %0\n\t"
  70                 "lw $30, %1\n\t" : : "m" (env[0].__sp), "m" (env[0].__fp));
  71
  72 /* Give setjmp 1 if given a 0, or what they gave us if non-zero.  */
  73   if (val == 0)
  74     asm volatile ("li $2, 1");
  75   else
  76     asm volatile ("move $2, %0" : : "r" (val));
  77
  78   asm volatile ("jr $25");
  79
  80   /* Avoid `volatile function does return' warnings.  */
  81   for (;;);
  82 }
  83
  84 /* Not using strong_alias because the nomips16 attribute cannot be
  85    copied from ____longjmp to __longjmp, because of the
  86    architecture-independent declaration of __longjmp without the
  87    attribute and compiler errors for such attributes not being the
  88    same on all declarations.  */
  89 extern __typeof (____longjmp) __longjmp __attribute__ ((alias ("____longjmp")));