[thirdparty/gcc.git] / libgcc / config / rl78 / trampoline.S

/* libgcc routines for RL78
   Copyright (C) 2011-2023 Free Software Foundation, Inc.
   Contributed by Red Hat.

   This file is part of GCC.

   GCC is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published
   by the Free Software Foundation; either version 3, or (at your
   option) any later version.

   GCC 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 General Public
   License for more details.

   Under Section 7 of GPL version 3, you are granted additional
   permissions described in the GCC Runtime Library Exception, version
   3.1, as published by the Free Software Foundation.

   You should have received a copy of the GNU General Public License and
   a copy of the GCC Runtime Library Exception along with this program;
   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
   <http://www.gnu.org/licenses/>.  */

/* RL78 Trampoline support

  Since the RL78's RAM is not in the first 64k, we cannot "just" use a
  function pointer to point to a trampoline on the stack.  So, we
  create N fixed trampolines that read from an array, and allocate
  them as needed.

*/

#include "vregs.h"

	.data
	.p2align	1
trampoline_array:

	.macro stub n

	.text
trampoline_\n:
        .type   trampoline_\n, @function
	movw	ax, !trampoline_chain_\n
	movw	r14, ax
	movw	ax, !trampoline_addr_\n
	br	ax
	.size	trampoline_\n, .-trampoline_\n

	.data
trampoline_frame_\n:
	.short	0
trampoline_stub_\n:
	.short	trampoline_\n
trampoline_chain_\n:
	.short	0
trampoline_addr_\n:
	.short	0

#define TO_FRAME 0
#define TO_STUB  2
#define TO_CHAIN 4
#define TO_ADDR  6
#define TO_SIZE  8

	.endm

	stub	0
	stub	1
	stub	2
	stub	3
	stub	4
	stub	5

trampoline_array_end:

/* Given the function pointer in R8 and the static chain
   pointer in R10, allocate a trampoline and return its address in
   R8. */

START_FUNC ___trampoline_init
	movw	hl, #trampoline_array

1:	movw	ax, [hl + TO_ADDR]
	cmpw	ax, #0
	bz	$2f

	movw	ax, hl
	addw	ax, #TO_SIZE
	movw	hl, ax
	cmpw	ax, #trampoline_array_end
	bnz	$1b
	brk			; no more slots?

2:	movw	ax, r8
	movw	[hl + TO_ADDR], ax
	movw	ax, r10
	movw	[hl + TO_CHAIN], ax
	movw	ax, sp
	movw	[hl + TO_FRAME], ax

	movw	ax, [hl + TO_STUB]
	movw	r8, ax
	ret
END_FUNC ___trampoline_init


START_FUNC ___trampoline_uninit
	movw	hl, #trampoline_array
	movw	ax, sp
	movw	bc, ax

1:	movw	ax, [hl + TO_FRAME]
	cmpw	ax, bc
	bc	$2f

	clrw	ax
	movw	[hl + TO_ADDR], ax

2:	movw	ax, hl
	addw	ax, #TO_SIZE
	movw	hl, ax
	cmpw	ax, #trampoline_array_end
	bnz	$1b

	ret
END_FUNC ___trampoline_uninit
Commit	Line	Data
85b8555e	1	/* libgcc routines for RL78
83ffe9cd	2	Copyright (C) 2011-2023 Free Software Foundation, Inc.
85b8555e DD	3	Contributed by Red Hat.
	4
	5	This file is part of GCC.
	6
	7	GCC is free software; you can redistribute it and/or modify it
	8	under the terms of the GNU General Public License as published
	9	by the Free Software Foundation; either version 3, or (at your
	10	option) any later version.
	11
	12	GCC is distributed in the hope that it will be useful, but WITHOUT
	13	ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
	14	or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
	15	License for more details.
	16
	17	Under Section 7 of GPL version 3, you are granted additional
	18	permissions described in the GCC Runtime Library Exception, version
	19	3.1, as published by the Free Software Foundation.
	20
	21	You should have received a copy of the GNU General Public License and
	22	a copy of the GCC Runtime Library Exception along with this program;
	23	see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
	24	<http://www.gnu.org/licenses/>. */
	25
	26	/* RL78 Trampoline support
	27
	28	Since the RL78's RAM is not in the first 64k, we cannot "just" use a
	29	function pointer to point to a trampoline on the stack. So, we
	30	create N fixed trampolines that read from an array, and allocate
	31	them as needed.
	32
	33	*/
	34
5c0029de	35	#include "vregs.h"
85b8555e DD	36
	37	.data
	38	.p2align 1
	39	trampoline_array:
	40
	41	.macro stub n
	42
	43	.text
	44	trampoline_\n:
	45	.type trampoline_\n, @function
	46	movw ax, !trampoline_chain_\n
	47	movw r14, ax
	48	movw ax, !trampoline_addr_\n
	49	br ax
	50	.size trampoline_\n, .-trampoline_\n
	51
	52	.data
	53	trampoline_frame_\n:
	54	.short 0
	55	trampoline_stub_\n:
	56	.short trampoline_\n
	57	trampoline_chain_\n:
	58	.short 0
	59	trampoline_addr_\n:
	60	.short 0
	61
	62	#define TO_FRAME 0
	63	#define TO_STUB 2
	64	#define TO_CHAIN 4
	65	#define TO_ADDR 6
	66	#define TO_SIZE 8
	67
	68	.endm
	69
	70	stub 0
	71	stub 1
	72	stub 2
	73	stub 3
	74	stub 4
	75	stub 5
	76
	77	trampoline_array_end:
	78
	79	/* Given the function pointer in R8 and the static chain
	80	pointer in R10, allocate a trampoline and return its address in
	81	R8. */
	82
8410904a	83	START_FUNC ___trampoline_init
85b8555e	84	movw hl, #trampoline_array
8410904a NC	85
8410904a NC	86	1: movw ax, [hl + TO_ADDR]
85b8555e DD	87	cmpw ax, #0
	88	bz $2f
	89
	90	movw ax, hl
	91	addw ax, #TO_SIZE
	92	movw hl, ax
	93	cmpw ax, #trampoline_array_end
	94	bnz $1b
	95	brk ; no more slots?
	96
	97	2: movw ax, r8
	98	movw [hl + TO_ADDR], ax
	99	movw ax, r10
	100	movw [hl + TO_CHAIN], ax
	101	movw ax, sp
	102	movw [hl + TO_FRAME], ax
	103
	104	movw ax, [hl + TO_STUB]
	105	movw r8, ax
85b8555e	106	ret
8410904a	107	END_FUNC ___trampoline_init
85b8555e	108
8410904a NC	109
8410904a NC	110	START_FUNC ___trampoline_uninit
85b8555e DD	111	movw hl, #trampoline_array
	112	movw ax, sp
	113	movw bc, ax
8410904a NC	114
8410904a NC	115	1: movw ax, [hl + TO_FRAME]
85b8555e DD	116	cmpw ax, bc
	117	bc $2f
	118
	119	clrw ax
	120	movw [hl + TO_ADDR], ax
	121
8410904a	122	2: movw ax, hl
85b8555e DD	123	addw ax, #TO_SIZE
	124	movw hl, ax
	125	cmpw ax, #trampoline_array_end
	126	bnz $1b
	127
	128	ret
8410904a	129	END_FUNC ___trampoline_uninit