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-rw-r--r--libc/sysdeps/linux/sparc/__longjmp.S92
1 files changed, 92 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/sparc/__longjmp.S b/libc/sysdeps/linux/sparc/__longjmp.S
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+++ b/libc/sysdeps/linux/sparc/__longjmp.S
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+/* Copyright (C) 1991, 93, 96, 97, 98, 99, 2000 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., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+/* Code taken from glibc/sysdeps/sparc/sparc32/ (glibc 2.2.2) */
+
+//#include "sysdep.h"
+#include <sysdep.h>
+
+#define _ASM 1
+#define _SETJMP_H
+#include <bits/setjmp.h>
+#define ENV(base,reg) [%base + (reg * 4)]
+#define ST_FLUSH_WINDOWS 3
+#define RW_FP [%fp + 0x48]
+
+ENTRY(__longjmp)
+ /* Store our arguments in global registers so we can still
+ use them while unwinding frames and their register windows. */
+
+ ld ENV(o0,JB_FP), %g3 /* Cache target FP in register %g3. */
+ mov %o0, %g1 /* ENV in %g1 */
+ orcc %o1, %g0, %g2 /* VAL in %g2 */
+ be,a 0f /* Branch if zero; else skip delay slot. */
+ mov 1, %g2 /* Delay slot only hit if zero: VAL = 1. */
+0:
+ xor %fp, %g3, %o0
+ add %fp, 512, %o1
+ andncc %o0, 4095, %o0
+ bne thread
+ //bne LOC(thread)
+ cmp %o1, %g3
+ bl thread
+ //bl LOC(thread)
+
+ /* Now we will loop, unwinding the register windows up the stack
+ until the restored %fp value matches the target value in %g3. */
+
+//LOC(loop):
+loop:
+ cmp %fp, %g3 /* Have we reached the target frame? */
+ bl,a loop /* Loop while current fp is below target. */
+ //bl,a LOC(loop) /* Loop while current fp is below target. */
+ restore /* Unwind register window in delay slot. */
+ be,a found /* Better have hit it exactly. */
+ //be,a LOC(found) /* Better have hit it exactly. */
+ ld ENV(g1,JB_SP), %o0 /* Delay slot: extract target SP. */
+
+thread:
+//LOC(thread):
+ /*
+ * 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 ENV(g1,JB_PC), %o7 /* Set return PC. */
+ ld ENV(g1,JB_SP), %fp /* Set saved SP on restore below. */
+ sub %fp, 64, %sp /* Allocate a register frame. */
+ st %g3, RW_FP /* Set saved FP on restore below. */
+ retl
+ restore %g2, 0, %o0 /* Restore values from above register frame. */
+
+found:
+//LOC(found):
+ /* We have unwound register windows so %fp matches the target. */
+ mov %o0, %sp /* OK, install new SP. */
+
+//LOC(sp_ok):
+sp_ok:
+ ld ENV(g1,JB_PC), %o0 /* Extract target return PC. */
+ jmp %o0 + 8 /* Return there. */
+ mov %g2, %o0 /* Delay slot: set return value. */
+
+END(__longjmp)