/* Copyright (C) 1991-2018 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 Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>

#include <jmpbuf-offsets.h>

#define ENV(base,reg) [%base + (reg * 4)]

#define ST_FLUSH_WINDOWS 3

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.  */

#ifdef PTR_DEMANGLE

	PTR_DEMANGLE (%g3, %g3, %g4)

#endif

	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 LOC(thread)

	 cmp %o1, %g3

	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):

	cmp %fp, %g3		/* Have we reached the target frame? */

	bl,a LOC(loop)		/* Loop while current fp is below target.  */

	 restore		/* Unwind register window in delay slot.  */

	be,a LOC(found)		/* Better have hit it exactly.  */

	 ld ENV(g1,JB_SP), %o0	/* Delay slot: extract target SP.  */

LOC(thread):

	save	%sp, -96, %sp

	/*

	 * 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

#ifdef PTR_DEMANGLE

	ld	ENV(g1,JB_PC), %g5 /* Set return PC. */

	ld	ENV(g1,JB_SP), %g1 /* Set saved SP on restore below. */

	PTR_DEMANGLE2 (%i7, %g5, %g4)

	PTR_DEMANGLE2 (%fp, %g1, %g4)

#else

	ld	ENV(g1,JB_PC), %i7 /* Set return PC. */

	ld	ENV(g1,JB_SP), %fp /* Set saved SP on restore below. */

#endif

	jmp	%i7 + 8

	 restore %g2, 0, %o0	/* Restore values from above register frame. */

LOC(found):

	/* We have unwound register windows so %fp matches the target.  */

#ifdef PTR_DEMANGLE

	PTR_DEMANGLE2 (%sp, %o0, %g4)

#else

	mov %o0, %sp		/* OK, install new SP.  */

#endif

LOC(sp_ok):

	ld ENV(g1,JB_PC), %o0	/* Extract target return PC.  */

#ifdef PTR_DEMANGLE

	PTR_DEMANGLE2 (%o0, %o0, %g4)

#endif

	jmp %o0 + 8		/* Return there.  */

	 mov %g2, %o0		/* Delay slot: set return value.  */

END(__longjmp)