[picodrive.git] / pico / misc_arm.s

/*
 * Generic memory routines.
 * (C) notaz, 2007-2008
 *
 * This work is licensed under the terms of MAME license.
 * See COPYING file in the top-level directory.
 */

@ 0x12345678 -> 0x34127856
@ r4=temp, lr=0x00ff00ff
.macro bswap reg
    and     r4,   \reg, lr
    and     \reg, lr,   \reg, lsr #8
    orr     \reg, \reg, r4,   lsl #8
.endm

@ dest must be halfword aligned, src can be unaligned
.global memcpy16bswap @ unsigned short *dest, void *src, int count

memcpy16bswap:
    tst     r1, #1
    bne     mcp16bs_cant_align2

    eor     r3, r0, r1
    tst     r3, #2
    bne     mcp16bs_cant_align

    tst     r0, #2
    beq     mcp16bs_aligned
    ldrh    r3, [r1], #2
    sub     r2, r2, #1
    orr     r3, r3, r3, lsl #16
    mov     r3, r3, lsr #8
    strh    r3, [r0], #2

mcp16bs_aligned:
    stmfd   sp!, {r4,lr}
    mov     lr, #0xff
    orr     lr, lr, lr, lsl #16

    subs    r2, r2, #4
    bmi     mcp16bs_fin4

mcp16bs_loop:
    ldmia   r1!, {r3,r12}
    subs    r2, r2, #4
    bswap   r3
    bswap   r12
    stmia   r0!, {r3,r12}
    bpl     mcp16bs_loop

mcp16bs_fin4:
    tst     r2, #2
    beq     mcp16bs_fin2
    ldr     r3, [r1], #4
    bswap   r3
    str     r3, [r0], #4

mcp16bs_fin2:
    ldmfd   sp!, {r4,lr}
    ands    r2, r2, #1
    bxeq    lr

mcp16bs_cant_align:
    ldrh    r3, [r1], #2
    subs    r2, r2, #1
    orr     r3, r3, r3, lsl #16
    mov     r3, r3, lsr #8
    strh    r3, [r0], #2
    bne     mcp16bs_cant_align
    bx      lr

    @ worst case
mcp16bs_cant_align2:
    ldrb    r3, [r1], #1
    ldrb    r12,[r1], #1
    subs    r2, r2, #1
    mov     r3, r3, lsl #8
    orr     r3, r3, r12
    strh    r3, [r0], #2
    bne     mcp16bs_cant_align2
    bx      lr


.global memset32 @ int *dest, int c, int count

memset32:
    stmfd   sp!, {lr}

    mov     r3, r1
    subs    r2, r2, #4
    bmi     mst32_fin

    mov     r12,r1
    mov     lr, r1

mst32_loop:
    subs    r2, r2, #4
    stmia   r0!, {r1,r3,r12,lr}
    bpl     mst32_loop

mst32_fin:
    tst     r2, #1
    strne   r1, [r0], #4

    tst     r2, #2
    stmneia r0!, {r1,r3}

    ldmfd   sp!, {lr}
    bx      lr

@ vim:filetype=armasm
Commit	Line	Data
cff531af	1	/*
	2	* Generic memory routines.
	3	* (C) notaz, 2007-2008
	4	*
	5	* This work is licensed under the terms of MAME license.
	6	* See COPYING file in the top-level directory.
	7	*/
fa1e5e29	8
0a051f55	9	@ 0x12345678 -> 0x34127856
	10	@ r4=temp, lr=0x00ff00ff
	11	.macro bswap reg
	12	and r4, \reg, lr
	13	and \reg, lr, \reg, lsr #8
	14	orr \reg, \reg, r4, lsl #8
	15	.endm
	16
0a051f55	17	@ dest must be halfword aligned, src can be unaligned
	18	.global memcpy16bswap @ unsigned short dest, void src, int count
	19
	20	memcpy16bswap:
	21	tst r1, #1
	22	bne mcp16bs_cant_align2
	23
	24	eor r3, r0, r1
	25	tst r3, #2
	26	bne mcp16bs_cant_align
	27
	28	tst r0, #2
	29	beq mcp16bs_aligned
	30	ldrh r3, [r1], #2
	31	sub r2, r2, #1
	32	orr r3, r3, r3, lsl #16
	33	mov r3, r3, lsr #8
	34	strh r3, [r0], #2
	35
	36	mcp16bs_aligned:
	37	stmfd sp!, {r4,lr}
	38	mov lr, #0xff
	39	orr lr, lr, lr, lsl #16
	40
	41	subs r2, r2, #4
	42	bmi mcp16bs_fin4
	43
	44	mcp16bs_loop:
	45	ldmia r1!, {r3,r12}
	46	subs r2, r2, #4
	47	bswap r3
	48	bswap r12
	49	stmia r0!, {r3,r12}
	50	bpl mcp16bs_loop
	51
	52	mcp16bs_fin4:
	53	tst r2, #2
	54	beq mcp16bs_fin2
	55	ldr r3, [r1], #4
	56	bswap r3
	57	str r3, [r0], #4
	58
	59	mcp16bs_fin2:
	60	ldmfd sp!, {r4,lr}
	61	ands r2, r2, #1
	62	bxeq lr
	63
	64	mcp16bs_cant_align:
	65	ldrh r3, [r1], #2
	66	subs r2, r2, #1
	67	orr r3, r3, r3, lsl #16
	68	mov r3, r3, lsr #8
	69	strh r3, [r0], #2
	70	bne mcp16bs_cant_align
	71	bx lr
	72
	73	@ worst case
	74	mcp16bs_cant_align2:
	75	ldrb r3, [r1], #1
	76	ldrb r12,[r1], #1
	77	subs r2, r2, #1
	78	mov r3, r3, lsl #8
	79	orr r3, r3, r12
	80	strh r3, [r0], #2
81	bne mcp16bs_cant_align2
82	bx lr
83
84
fa1e5e29	85	.global memset32 @ int *dest, int c, int count
	86
	87	memset32:
	88	stmfd sp!, {lr}
	89
	90	mov r3, r1
	91	subs r2, r2, #4
	92	bmi mst32_fin
	93
	94	mov r12,r1
	95	mov lr, r1
	96
	97	mst32_loop:
	98	subs r2, r2, #4
	99	stmia r0!, {r1,r3,r12,lr}
	100	bpl mst32_loop
	101
	102	mst32_fin:
	103	tst r2, #1
	104	strne r1, [r0], #4
	105
	106	tst r2, #2
	107	stmneia r0!, {r1,r3}
	108
	109	ldmfd sp!, {lr}
	110	bx lr
	111
cff531af	112	@ vim:filetype=armasm