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ARM asm LCD and ATA driver functions: Don't save r12 as it is a scratch reg. Saves a bit of stack and execution time.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21795 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jens Arnold 2009-07-11 23:43:44 +00:00
parent fa59ed6ae7
commit 47d4c4739b
12 changed files with 256 additions and 261 deletions
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64
firmware/target/arm/ata-as-arm.S
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@ -56,11 +56,11 @@
* r0 - current address
* r1 - word count
* r2 - ata port
* r3..r6, lr - read buffers
* r3..r5, r12, lr - read buffers
*/
copy_read_sectors:
stmfd sp!, {r4, r5, r6, lr}
stmfd sp!, {r4, r5, lr}
ldr r2, =.ata_port
tst r0, #1 /* 16 bit aligned? */
beq .r_aligned
@ -92,16 +92,16 @@ copy_read_sectors:
ldrh r5, [r2]
orr r4, r4, r5, lsl #24
mov r5, r5, lsr #8
ldrh r6, [r2]
orr r5, r5, r6, lsl #8
ldrh r6, [r2]
orr r5, r5, r6, lsl #24
mov r6, r6, lsr #8
ldrh r12, [r2]
orr r5, r5, r12, lsl #8
ldrh r12, [r2]
orr r5, r5, r12, lsl #24
mov r12, r12, lsr #8
ldrh lr, [r2]
orr r6, r6, lr, lsl #8
orr r12, r12, lr, lsl #8
ldrh lr, [r2]
orr r6, r6, lr, lsl #24
stmia r0!, {r3, r4, r5, r6}
orr r12, r12, lr, lsl #24
stmia r0!, {r3, r4, r5, r12}
mov r3, lr, lsr #8
subs r1, r1, #8 /* 8 or more halfwords left? */
bge .r_loop_u
@ -140,7 +140,7 @@ copy_read_sectors:
strb r3, [r0], #1 /* store final byte */
ldmfd sp!, {r4, r5, r6, pc}
ldmfd sp!, {r4, r5, pc}
/* 16-bit aligned */
.r_aligned:
@ -158,12 +158,12 @@ copy_read_sectors:
ldrh r5, [r2]
orr r4, r4, r5, lsl #16
ldrh r5, [r2]
ldrh r6, [r2]
orr r5, r5, r6, lsl #16
ldrh r6, [r2]
ldrh r12, [r2]
orr r5, r5, r12, lsl #16
ldrh r12, [r2]
ldrh lr, [r2]
orr r6, r6, lr, lsl #16
stmia r0!, {r3, r4, r5, r6}
orr r12, r12, lr, lsl #16
stmia r0!, {r3, r4, r5, r12}
subs r1, r1, #8 /* 8 or more halfwords left? */
bge .r_loop_a
@ -189,7 +189,7 @@ copy_read_sectors:
ldrneh r3, [r2]
strneh r3, [r0], #2
ldmfd sp!, {r4, r5, r6, pc}
ldmfd sp!, {r4, r5, pc}
.r_end:
.size copy_read_sectors,.r_end-copy_read_sectors
@ -210,11 +210,11 @@ copy_read_sectors:
* r0 - current address
* r1 - word count
* r2 - ata port
* r3..r6, lr - read buffers
* r3..r5, r12, lr - read buffers
*/
copy_write_sectors:
stmfd sp!, {r4, r5, r6, lr}
stmfd sp!, {r4, r5, lr}
ldr r2, =.ata_port
tst r0, #1 /* 16 bit aligned? */
beq .w_aligned
@ -234,7 +234,7 @@ copy_write_sectors:
sub r1, r1, #8 /* adjust for zero-check and doing 8 halfwords/loop */
.w_loop_u:
ldmia r0!, {r4, r5, r6, lr}
ldmia r0!, {r4, r5, r12, lr}
orr r3, r3, r4, lsl #8 /* Load 4 words at once and decompose them */
strh r3, [r2] /* into 8 halfwords in a way that the words */
mov r3, r3, lsr #16 /* are shifted by 8 bits, putting the high */
@ -245,15 +245,15 @@ copy_write_sectors:
mov r4, r4, lsr #16
strh r4, [r2]
mov r5, r5, lsr #24
orr r5, r5, r6, lsl #8
orr r5, r5, r12, lsl #8
strh r5, [r2]
mov r5, r5, lsr #16
strh r5, [r2]
mov r6, r6, lsr #24
orr r6, r6, lr, lsl #8
strh r6, [r2]
mov r6, r6, lsr #16
strh r6, [r2]
mov r12, r12, lsr #24
orr r12, r12, lr, lsl #8
strh r12, [r2]
mov r12, r12, lsr #16
strh r12, [r2]
mov r3, lr, lsr #24
subs r1, r1, #8 /* 8 or more halfwords left? */
bge .w_loop_u
@ -294,7 +294,7 @@ copy_write_sectors:
orr r3, r3, r4, lsl #8
strh r3, [r2] /* write final halfword */
ldmfd sp!, {r4, r5, r6, pc}
ldmfd sp!, {r4, r5, pc}
/* 16-bit aligned */
.w_aligned:
@ -305,7 +305,7 @@ copy_write_sectors:
sub r1, r1, #8 /* adjust for zero-check and doing 8 halfwords/loop */
.w_loop_a:
ldmia r0!, {r3, r4, r5, r6}
ldmia r0!, {r3, r4, r5, r12}
strh r3, [r2] /* Load 4 words and decompose them into */
mov r3, r3, lsr #16 /* 2 halfwords each, and write those. */
strh r3, [r2]
@ -315,9 +315,9 @@ copy_write_sectors:
strh r5, [r2]
mov r5, r5, lsr #16
strh r5, [r2]
strh r6, [r2]
mov r6, r6, lsr #16
strh r6, [r2]
strh r12, [r2]
mov r12, r12, lsr #16
strh r12, [r2]
subs r1, r1, #8 /* 8 or more halfwords left? */
bge .w_loop_a
@ -343,7 +343,7 @@ copy_write_sectors:
ldrneh r3, [r0], #2
strneh r3, [r2]
ldmfd sp!, {r4, r5, r6, pc}
ldmfd sp!, {r4, r5, pc}
.w_end:
.size copy_write_sectors,.w_end-copy_write_sectors