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Replaced jump table with a more efficient one.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7658 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Thom Johansen 2005-10-27 11:00:24 +00:00
parent 0b38c7dcbe
commit c2628f3af9
1 changed files with 11 additions and 14 deletions
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25
apps/codecs/libffmpegFLAC/coldfire.S
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@ -48,21 +48,18 @@ lpc_decode_emac:
moveq.l #8, %d3 moveq.l #8, %d3
cmp.l %d3, %d2 cmp.l %d3, %d2
jgt .default | order is over 8, jump to default case jgt .default | order is over 8, jump to default case
lea.l .jumptable, %a4 jmp.l (2, %pc, %d2.l*4) | jump to loop corresponding to pred_order
move.l (%a4, %d2.l*4), %a4
jmp (%a4)
.align 4 | avoid unaligned fetch
.jumptable: .jumptable:
.long .exit bra.w .exit | zero order filter isn't possible, exit function
.long .order1 bra.w .order1
.long .order2 bra.w .order2
.long .order3 bra.w .order3
.long .order4 bra.w .order4
.long .order5 bra.w .order5
.long .order6 bra.w .order6
.long .order7 bra.w .order7
.long .order8
| last jump table entry coincides with target, so leave it out
.order8: .order8:
movem.l (%a1), %d3-%d7/%a2-%a4 | load lpc coefs movem.l (%a1), %d3-%d7/%a2-%a4 | load lpc coefs
move.l (%a0)+, %a5 | load first history sample move.l (%a0)+, %a5 | load first history sample
@ -78,7 +75,7 @@ lpc_decode_emac:
movclr.l %acc0, %d2 | get sum movclr.l %acc0, %d2 | get sum
asr.l %d1, %d2 | shift sum by lp_quantization bits asr.l %d1, %d2 | shift sum by lp_quantization bits
add.l %d2, (%a0) | add residual and save add.l %d2, (%a0) | add residual and save
lea.l (-6*4, %a0), %a0 | history pointer points at second element lea.l (-6*4, %a0), %a0 | point history back at second element
subq.l #1, %d0 | decrement counter subq.l #1, %d0 | decrement counter
jne .loop8 | are we done? jne .loop8 | are we done?
jra .exit jra .exit