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| author | Nils Wallménius <nils@rockbox.org> | 2010-05-12 12:32:34 +0000 |
|---|---|---|
| committer | Nils Wallménius <nils@rockbox.org> | 2010-05-12 12:32:34 +0000 |
| commit | aa1e471f9aa05f56edd00a0bf70bb416efa0529f (patch) | |
| tree | 0859f03ec73b229bb7fb3d7f84d531f6bcb13c99 | |
| parent | a5d8d215964b31c3257083846dab71af51eb1af2 (diff) | |
| download | rockbox-aa1e471f9aa05f56edd00a0bf70bb416efa0529f.tar.gz rockbox-aa1e471f9aa05f56edd00a0bf70bb416efa0529f.zip | |
Coldfire strlen, slight optimization pointed out by amiconn, eliminate some unconditionla branches by rearranging the code handling the head bytes
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25968 a1c6a512-1295-4272-9138-f99709370657
| -rw-r--r-- | firmware/target/coldfire/strlen-coldfire.S | 11 |
1 files changed, 2 insertions, 9 deletions
diff --git a/firmware/target/coldfire/strlen-coldfire.S b/firmware/target/coldfire/strlen-coldfire.S index f1e5aca981..765969da04 100644 --- a/firmware/target/coldfire/strlen-coldfire.S +++ b/firmware/target/coldfire/strlen-coldfire.S | |||
| @@ -31,21 +31,14 @@ strlen: | |||
| 31 | move.l %a0, %a1 /* %a1 = start address */ | 31 | move.l %a0, %a1 /* %a1 = start address */ |
| 32 | move.l %a0, %d0 | 32 | move.l %a0, %d0 |
| 33 | andi.l #3, %d0 /* %d0 = %a0 & 3 */ | 33 | andi.l #3, %d0 /* %d0 = %a0 & 3 */ |
| 34 | jmp.l (2,%pc,%d0.l*2) | 34 | beq.b 1f /* already aligned */ |
| 35 | bra.b .bytes0 | 35 | jmp.l (-2,%pc,%d0.l*4) |
| 36 | bra.b .bytes3 | ||
| 37 | bra.b .bytes2 | ||
| 38 | bra.b .bytes1 | ||
| 39 | .bytes3: | ||
| 40 | tst.b (%a0)+ | 36 | tst.b (%a0)+ |
| 41 | beq.b .done | 37 | beq.b .done |
| 42 | .bytes2: | ||
| 43 | tst.b (%a0)+ | 38 | tst.b (%a0)+ |
| 44 | beq.b .done | 39 | beq.b .done |
| 45 | .bytes1: | ||
| 46 | tst.b (%a0)+ | 40 | tst.b (%a0)+ |
| 47 | beq.b .done | 41 | beq.b .done |
| 48 | .bytes0: | ||
| 49 | 42 | ||
| 50 | 1: | 43 | 1: |
| 51 | move.l (%a0)+, %d0 /* load %d0 increment %a0 */ | 44 | move.l (%a0)+, %d0 /* load %d0 increment %a0 */ |