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Sansa Clip : save one instruction per 8 pixels loop in lcd_grey_data

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We set directly the needed bits to write into DBOP_DOUT (15:13 and 3:0)
Since we can't set the mask 0xf00f with one mov instruction, revert the
logic and use orrne instead of biceq (in the whole function for consistency)

Fix suggested by Jens Arnold

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19279 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Rafaël Carré 2008-12-01 04:07:13 +00:00
parent c9ba3adf0d
commit 50519416ca
1 changed files with 12 additions and 10 deletions
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22
firmware/target/arm/as3525/sansa-clip/lcd-as-clip.S
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@ -59,32 +59,34 @@ lcd_grey_data:
ldmia r1, {r3-r4} /* Fetch 8 pixel phases */ ldmia r1, {r3-r4} /* Fetch 8 pixel phases */
ldmia r0!, {r5-r6} /* Fetch 8 pixel values */ ldmia r0!, {r5-r6} /* Fetch 8 pixel values */
mov r7, #0xff mov r7, #0
/* set bits 15..12 */
tst r3, #0x80 tst r3, #0x80
biceq r7, r7, #0x80 orrne r7, r7, #0x8000
tst r3, #0x8000 tst r3, #0x8000
biceq r7, r7, #0x40 orrne r7, r7, #0x4000
tst r3, #0x800000 tst r3, #0x800000
biceq r7, r7, #0x20 orrne r7, r7, #0x2000
tst r3, #0x80000000 tst r3, #0x80000000
biceq r7, r7, #0x10 orrne r7, r7, #0x1000
bic r3, r3, r8 bic r3, r3, r8
add r3, r3, r5 add r3, r3, r5
/* set bits 3..0 */
tst r4, #0x80 tst r4, #0x80
biceq r7, r7, #0x08 orrne r7, r7, #0x08
tst r4, #0x8000 tst r4, #0x8000
biceq r7, r7, #0x04 orrne r7, r7, #0x04
tst r4, #0x800000 tst r4, #0x800000
biceq r7, r7, #0x02 orrne r7, r7, #0x02
tst r4, #0x80000000 tst r4, #0x80000000
biceq r7, r7, #0x01 orrne r7, r7, #0x01
bic r4, r4, r8 bic r4, r4, r8
add r4, r4, r6 add r4, r4, r6
stmia r1!, {r3-r4} stmia r1!, {r3-r4}
orr r7, r7, r7, lsl #8 @ we set 15:13 to the MSb and 3:0 to the LSb
strh r7, [lr, #0x10] @ DBOP_DOUT strh r7, [lr, #0x10] @ DBOP_DOUT
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