[thirdparty/gcc.git] / libgcc / config / rl78 / lshrsi3.S

;   Copyright (C) 2011-2020 Free Software Foundation, Inc.
;   Contributed by Red Hat.
; 
; This file 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.
; 
; This file 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/>.

#include "vregs.h"
	
START_FUNC ___lshrsi3
	;; input:
	;; 
	;; [zero]
	;; [count]   <= $sp+8
	;; [in MSB]
	;; [in]
	;; [in]
	;; [in LSB]  <- $sp+4

	;; output:
	;; 
	;; [r8..r11] result

	;; registers:
	;;
	;; AX - temp for shift/rotate
	;; B  - count

	mov	a, [sp+8]	; A now contains the count
	cmp	a, #0x20
	bc	$.Lcount_is_normal

	;; count is out of bounds, just return zero.
	movw	r8, #0
	movw	r10, #0
	ret

.Lcount_is_normal:
	cmp0	a
	bnz	$.Lcount_is_nonzero

	;; count is zero, just copy IN to OUT
	movw	ax, [sp+4]
	movw	r8, ax
	movw	ax, [sp+6]
	movw	r10, ax
	ret

.Lcount_is_nonzero:
	mov	b, a		; B now contains the count also
	bf	a.4, $.Lcount_lt_16

	;; count >= 16, shift 16 at a time.
	movw	r10, #0
	movw	ax, [sp+6]
	movw	r8, ax
	mov	a, b
	and	a, #0x0f
	sknz
	ret

	mov	b, a		; B now contains the remaining count
	inc	b
	br	$.Lloop_top

.Lcount_lt_16:	
	;; count is nonzero.  Do one 
	movw	ax, [sp+6]
	shrw	ax,1
	movw	r10, ax
	mov	a, [sp+5]
	rorc	a,1
	mov	r9, a
	mov	a, [sp+4]
	rorc	a,1
	mov	r8, a

	;; we did one shift above; do as many more as we need now.
.Lloop_top:	
	dec	b
	sknz
	ret

	movw	ax, r10
	shrw	ax,1
	movw	r10, ax
	mov	a, r9
	rorc	a,1
	mov	r9, a
	mov	a, r8
	rorc	a,1
	mov	r8, a

	br	$.Lloop_top

END_FUNC ___lshrsi3
Commit	Line	Data
8d9254fc	1	; Copyright (C) 2011-2020 Free Software Foundation, Inc.
85b8555e DD	2	; Contributed by Red Hat.
	3	;
	4	; This file is free software; you can redistribute it and/or modify it
	5	; under the terms of the GNU General Public License as published by the
	6	; Free Software Foundation; either version 3, or (at your option) any
	7	; later version.
	8	;
	9	; This file is distributed in the hope that it will be useful, but
	10	; WITHOUT ANY WARRANTY; without even the implied warranty of
	11	; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	12	; General Public License for more details.
	13	;
	14	; Under Section 7 of GPL version 3, you are granted additional
	15	; permissions described in the GCC Runtime Library Exception, version
	16	; 3.1, as published by the Free Software Foundation.
	17	;
	18	; You should have received a copy of the GNU General Public License and
	19	; a copy of the GCC Runtime Library Exception along with this program;
	20	; see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
	21	; <http://www.gnu.org/licenses/>.
	22
5c0029de	23	#include "vregs.h"
85b8555e	24
8410904a	25	START_FUNC ___lshrsi3
85b8555e DD	26	;; input:
	27	;;
	28	;; [zero]
	29	;; [count] <= $sp+8
	30	;; [in MSB]
	31	;; [in]
	32	;; [in]
	33	;; [in LSB] <- $sp+4
	34
	35	;; output:
	36	;;
	37	;; [r8..r11] result
	38
	39	;; registers:
	40	;;
	41	;; AX - temp for shift/rotate
	42	;; B - count
	43
	44	mov a, [sp+8] ; A now contains the count
85b8555e DD	45	cmp a, #0x20
	46	bc $.Lcount_is_normal
	47
	48	;; count is out of bounds, just return zero.
	49	movw r8, #0
	50	movw r10, #0
	51	ret
	52
	53	.Lcount_is_normal:
	54	cmp0 a
	55	bnz $.Lcount_is_nonzero
	56
	57	;; count is zero, just copy IN to OUT
	58	movw ax, [sp+4]
	59	movw r8, ax
	60	movw ax, [sp+6]
	61	movw r10, ax
	62	ret
	63
	64	.Lcount_is_nonzero:
	65	mov b, a ; B now contains the count also
	66	bf a.4, $.Lcount_lt_16
	67
	68	;; count >= 16, shift 16 at a time.
	69	movw r10, #0
	70	movw ax, [sp+6]
	71	movw r8, ax
	72	mov a, b
	73	and a, #0x0f
	74	sknz
	75	ret
	76
	77	mov b, a ; B now contains the remaining count
	78	inc b
	79	br $.Lloop_top
	80
	81	.Lcount_lt_16:
	82	;; count is nonzero. Do one
	83	movw ax, [sp+6]
	84	shrw ax,1
	85	movw r10, ax
	86	mov a, [sp+5]
	87	rorc a,1
	88	mov r9, a
	89	mov a, [sp+4]
	90	rorc a,1
	91	mov r8, a
	92
	93	;; we did one shift above; do as many more as we need now.
	94	.Lloop_top:
	95	dec b
	96	sknz
	97	ret
	98
	99	movw ax, r10
	100	shrw ax,1
	101	movw r10, ax
	102	mov a, r9
	103	rorc a,1
	104	mov r9, a
	105	mov a, r8
	106	rorc a,1
	107	mov r8, a
	108
109	br $.Lloop_top
110
8410904a	111	END_FUNC ___lshrsi3