Aren/NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fast write_region_2, which is just the fast read_region_2 with different

Browse Source 
inner loops.
This commit is contained in:
bjh21 2006-10-03 23:15:18 +00:00
parent ca8f51da8c
commit d98bf2904c
1 changed files with 57 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
sys/arch/acorn26/acorn26/bus_asm.S
View File

@ -1,4 +1,4 @@
/* $NetBSD: bus_asm.S,v 1.3 2006/10/03 22:27:02 bjh21 Exp $ */
/* $NetBSD: bus_asm.S,v 1.4 2006/10/03 23:15:18 bjh21 Exp $ */
/*
* Copyright (c) 2006 Ben Harris
@ -303,27 +303,72 @@ ENTRY(iobus_bs_wr_1)
ENTRY(iobus_bs_wr_2)
mov ip, sp
stmfd sp!, {r4, fp, ip, lr, pc}
stmfd sp!, {r4-r10, fp, ip, lr, pc}
sub fp, ip, #4
add r12, r1, r2, lsl r0
add r8, r1, r2, lsl r0
mov r9, r3
mov r2, #1
mov r0, r2, lsl r0
ldr r2, [sp, #20]
ldr r10, [sp, #44]
teq r0, #4 /* Is the step 4? */
movne r7, r10 /* If not, do the whole lot slowly. */
rsbeq r7, r9, #0 /* Otherwise, go slowly to a */
andeq r7, r7, #15 /* 16-byte boundary. */
moveq r7, r7, lsr #1 /* Convert to uint16_ts */
sub r10, r10, r7 /* Adjust fast transfer len to match */
cmp r10, #8
addlt r7, r7, r10 /* If remaining fast xfer is <8 */
movlt r10, #0 /* make it zero and correct r7. */
/* Make sure that we have a positive length */
cmp r2, #0x00000000
ldmledb fp, {fp, sp, pc}
teq r7, #0
beq 2f
1:
ldrb r1, [r3], #0x0001
ldrb r4, [r3], #1
1: ldrb r1, [r9], #0x0001
ldrb r4, [r9], #1
orr r1, r1, r4, lsl #8
orr r1, r1, r1, lsl #16
str r1, [r12], r0
subs r2, r2, #0x00000001
str r1, [r8], r0
subs r7, r7, #1
bgt 1b
ldmdb fp, {r4, fp, sp, pc}
2: teq r10, #0
ldmeqdb fp, {r4-r10, fp, sp, pc}
/*
* Fast write_region_2 code. This is at its best when dealing with
* 16-byte-aligned blocks of memory, which is arranged by the code
* above.
*
* The EOR trick goes:
* rH = (H)(L)
* eor rL, rH, rH, lsl #16 rL = (H^L)(L)
* eor rH, rH, rL, lsr #16 rH = (H)(L^H^L) = (H)(H)
* eor rL, rL, rH, lsl #16 rL = (H^L^H)(L) = (L)(L)
*/
sub r10, r10, #7
2: ldmia r9!, {r1, r3, r5, r7}
subs r10, r10, #8
eor r0, r1, r1, lsl #16
eor r2, r3, r3, lsl #16
eor r4, r5, r5, lsl #16
eor r6, r7, r7, lsl #16
eor r1, r1, r0, lsr #16
eor r3, r3, r2, lsr #16
eor r5, r5, r4, lsr #16
eor r7, r7, r6, lsr #16
eor r0, r0, r1, lsl #16
eor r2, r2, r3, lsl #16
eor r4, r4, r5, lsl #16
eor r6, r6, r7, lsl #16
stmia r8!, {r0-r7}
bgt 2b
adds r7, r10, #7
ldmeqdb fp, {r4-r10, fp, sp, pc}
mov r0, #4
mov r10, #0
b 1b
/*
* set multiple