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authorRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
committerRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
commit28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch)
tree15f07c4c43d635959c6afee96bde71fb1b3614ee /sysdeps/alpha/__longjmp.c
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diff --git a/sysdeps/alpha/__longjmp.c b/sysdeps/alpha/__longjmp.c
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+/* Copyright (C) 1992, 1994 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+/* Global register vars must come before any function defn.  */
+
+register long int
+  r9 asm ("$9"), r10 asm ("$10"), r11 asm ("$11"), r12 asm ("$12"),
+  r13 asm ("$13"), r14 asm ("$14");
+
+register long int *fp asm ("$15"), *sp asm ("$30"), *retpc asm ("$26");
+
+#if 1				/* XXX */
+register double
+  f2 asm ("$f2"), f3 asm ("$f3"), f4 asm ("$f4"), f5 asm ("$f5"),
+  f6 asm ("$f6"), f7 asm ("$f7"), f8 asm ("$f8"), f9 asm ("$f9");
+#endif
+
+#include <setjmp.h>
+
+
+/* Jump to the position specified by ENV, causing the
+   setjmp call there to return VAL, or 1 if VAL is 0.  */
+__NORETURN 
+void
+__longjmp (const __jmp_buf env, int val)
+{
+  /* Restore the integer registers.  */
+  r9 = env[0].__9;
+  r10 = env[0].__10;
+  r11 = env[0].__11;
+  r12 = env[0].__12;
+  r13 = env[0].__13;
+  r14 = env[0].__14;
+
+#if 1				/* XXX */
+  /* Restore the floating point registers.  */
+  f2 = env[0].__f2;
+  f3 = env[0].__f3;
+  f4 = env[0].__f4;
+  f5 = env[0].__f5;
+  f6 = env[0].__f6;
+  f7 = env[0].__f7;
+  f8 = env[0].__f8;
+  f9 = env[0].__f9;
+#endif
+
+  /* Set the return PC to that of setjmp's caller.  */
+  retpc = env[0].__pc;
+
+  /* Restore the FP and SP of setjmp's caller.  */
+  fp = env[0].__fp;
+  sp = env[0].__sp;
+
+  /* Return VAL (or 1 if VAL is zero) to setjmp's caller.
+
+     We use an asm here rather than a normal C return statement
+     just in case the compiler wanted to do some stack frobnication
+     in the function epilogue.  Since we have already restored
+     precisely the FP and SP the desired environment needs,
+     we must avoid the compiler doing anything with the stack.  */
+
+  while (1)
+    {
+      /* The loop is just to avoid `volatile function does return' warnings.
+	 The instruction will only be executed once.  */
+
+      register long int retval asm ("$0");
+
+      asm volatile
+	("cmoveq %1, 1, %0\n\t"	/* $0 = val ?: 1; */
+	 "ret $31, (%2), 1"	/* return $0 */
+	 : "=r" (retval)
+	 /* The "0" constraint should force VAL into $0.  */
+	 : "0" (val), "r" (retpc));
+    }
+}