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-rw-r--r--sysdeps/sparc/__longjmp.S63
1 files changed, 37 insertions, 26 deletions
diff --git a/sysdeps/sparc/__longjmp.S b/sysdeps/sparc/__longjmp.S
index adff06e349..38bc7bbac8 100644
--- a/sysdeps/sparc/__longjmp.S
+++ b/sysdeps/sparc/__longjmp.S
@@ -1,4 +1,4 @@
-/* Copyright (C) 1991, 1993 Free Software Foundation, Inc.
+/* Copyright (C) 1991, 1993, 1996 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
@@ -17,31 +17,42 @@ not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <sysdep.h>
-#ifdef __svr4__
-#include <sys/trap.h>
-#else
-#include <machine/trap.h>
-#endif
-/* NOTE: This code depends on the definition of `__jmp_buf' in <jmp_buf.h>. */
+#include <jmp_buf.h>
+#define ENV(reg) [%g1 + (reg * 4)]
ENTRY (__longjmp)
- /* Do a "flush register windows trap". The trap handler in the
- kernel writes all the register windows to their stack slots, and
- marks them all as invalid (needing to be sucked up from the
- stack when used). This ensures that all information needed to
- unwind to these callers is in memory, not in the register
- windows. */
- ta ST_FLUSH_WINDOWS
- ld [%o0], %o7 /* Return PC. */
- ld [%o0 + 4], %fp /* Saved SP. */
- sub %fp, 64, %sp /* Allocate a register save area. */
-
- /* if (%o1 == 0) %o1 = 1; */
- tst %o1
- be,a Ldone
- mov 1, %o1
-
-Ldone: retl
- /* On the way out, put the return value in %o0. */
- restore %o1, 0, %o0
+ /* Store our arguments in global registers so we can still
+ use them while unwinding frames and their register windows. */
+ mov %o0, %g1 /* ENV in %g1 */
+ orcc %o1, %g0, %g6 /* VAL in %g6 */
+ be,a 0f /* Branch if zero; else skip delay slot. */
+ mov 1, %g6 /* Delay slot only hit if zero: VAL = 1. */
+0:
+
+ /* Cache target FP in register %g7. */
+ ld ENV (JB_FP), %g7
+
+ /* Now we will loop, unwinding the register windows up the stack
+ until the restored %fp value matches the target value in %g7. */
+
+loop: cmp %fp, %g7 /* Have we reached the target frame? */
+ bl,a loop /* Loop while current fp is below target. */
+ restore /* Unwind register window in delay slot. */
+ be,a found /* Better have hit it exactly. */
+ ld ENV (JB_SP), %o0 /* Delay slot: extract target SP. */
+
+bogus: /* Get here only if the jmp_buf or stack is clobbered. */
+ call C_SYMBOL_NAME (abort)
+ nop
+ unimp 0
+
+found: /* We have unwound register windows so %fp matches the target. */
+ cmp %o0, %sp /* Check jmp_buf SP vs register window. */
+ bge,a sp_ok /* Saved must not be deeper than register. */
+ mov %o0, %sp /* OK, install new SP. */
+ b,a bogus /* Bogus, we lose. */
+
+sp_ok: ld ENV (JB_PC), %o0 /* Extract target return PC. */
+ jmp %o0 + 8 /* Return there. */
+ mov %g6, %o0 /* Delay slot: set return value. */