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

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

1 files changed, 12 insertions, 10 deletions

diff --git a/firmware/target/arm/as3525/sansa-clip/lcd-as-clip.S b/firmware/target/arm/as3525/sansa-clip/lcd-as-clip.S
index aab46861ba..0f68a2f664 100644
--- a/firmware/target/arm/as3525/sansa-clip/lcd-as-clip.S
+++ b/firmware/target/arm/as3525/sansa-clip/lcd-as-clip.S
@@ -59,32 +59,34 @@ lcd_grey_data:
     ldmia   r1, {r3-r4}         /* Fetch 8 pixel phases */
     ldmia   r0!, {r5-r6}        /* Fetch 8 pixel values */
 
-    mov     r7, #0xff
+    mov     r7, #0
+
+    /* set bits 15..12 */
     tst     r3, #0x80
-    biceq   r7, r7, #0x80
+    orrne   r7, r7, #0x8000
     tst     r3, #0x8000
-    biceq   r7, r7, #0x40
+    orrne   r7, r7, #0x4000
     tst     r3, #0x800000
-    biceq   r7, r7, #0x20
+    orrne   r7, r7, #0x2000
     tst     r3, #0x80000000
-    biceq   r7, r7, #0x10
+    orrne   r7, r7, #0x1000
     bic     r3, r3, r8
     add     r3, r3, r5
 
+    /* set bits 3..0 */
     tst     r4, #0x80
-    biceq   r7, r7, #0x08
+    orrne   r7, r7, #0x08
     tst     r4, #0x8000
-    biceq   r7, r7, #0x04
+    orrne   r7, r7, #0x04
     tst     r4, #0x800000
-    biceq   r7, r7, #0x02
+    orrne   r7, r7, #0x02
     tst     r4, #0x80000000
-    biceq   r7, r7, #0x01
+    orrne   r7, r7, #0x01
     bic     r4, r4, r8
     add     r4, r4, r6
 
     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
 
 1: