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libmusepack: tiny optimization of the ARMv4 mpc_decoder_windowing_D implementations, using register indexed addressing to store data, saving one instruction in the loop and deleting one instruction adter the loop which isn't needed.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@28488 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Nils Wallménius 2010-11-05 11:49:30 +00:00
parent dbdc0a8a8c
commit 9d98583a18
1 changed files with 9 additions and 13 deletions
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22
apps/codecs/libmusepack/synth_filter_arm.S
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@ -164,7 +164,7 @@ mpc_decoder_windowing_D:
* r10 = lo, r11 = hi of 31..17
* r12 = V[31..16]
*****************************************/
mov lr, #15
mov lr, #15*8
add r12, r1, #30*4 /* r12 = V[31] */
.loop15:
ldmia r2!, { r3-r6 } /* load D[00..03] */
@ -240,19 +240,18 @@ mpc_decoder_windowing_D:
orr r8, r8, r9, lsl #16 /* (lo>>16) || (hi<<16) */
str r8, [r0] /* store Data */
/* store Data[31..17] */
add r0, r0, lr, asl #3 /* r0 = r0 + 2*lr [words] */
mov r10, r10, lsr #16
orr r10, r10, r11, lsl #16 /* (lo>>16) || (hi<<16) */
rsb r10, r10, #0 /* r10 = -r10 */
str r10, [r0], #4 /* store Data */
sub r0, r0, lr, asl #3 /* r0 = r0 - 2*lr [words] */
str r10, [r0, lr] /* store Data */
add r0, r0, #4 /* r0++ */
/* correct adresses for next loop */
sub r12, r12, #4 /* r12 = V-- */
add r1, r1, #4 /* r1 = V++ */
/* next loop */
subs lr, lr, #1
subs lr, lr, #8
bgt .loop15
/******************************************
* V[16] with internal symmetry
*****************************************/
@ -293,7 +292,6 @@ mpc_decoder_windowing_D:
mov r8, r8, lsr #16
orr r8, r8, r9, lsl #16 /* (lo>>16) || (hi<<16) */
str r8, [r0], #4 /* store Data */
add r1, r1, #4 /* V++ */
ldmpc regs=r4-r11
#elif ARM_ARCH < 6 /* arm9 and above */
@ -365,7 +363,7 @@ mpc_decoder_windowing_D:
* r10 = lo, r11 = hi of 31..17
* r12 = V[31..16]
*****************************************/
mov lr, #15
mov lr, #15*8
add r12, r1, #30*4 /* r12 = V[31] */
.loop15:
ldmia r2!, { r3-r4 } /* load D[00..01] */
@ -445,17 +443,16 @@ mpc_decoder_windowing_D:
orr r8, r8, r9, lsl #16 /* (lo>>16) || (hi<<16) */
str r8, [r0] /* store Data */
/* store Data[31..17] */
add r0, r0, lr, asl #3 /* r0 = r0 + 2*lr [words] */
mov r10, r10, lsr #16
orr r10, r10, r11, lsl #16 /* (lo>>16) || (hi<<16) */
rsb r10, r10, #0 /* r10 = -r10 */
str r10, [r0], #4 /* store Data */
sub r0, r0, lr, asl #3 /* r0 = r0 - 2*lr [words] */
str r10, [r0, lr] /* store Data */
add r0, r0, #4 /* r0++ */
/* correct adresses for next loop */
sub r12, r12, #4 /* r12 = V-- */
add r1, r1, #4 /* r1 = V++ */
/* next loop */
subs lr, lr, #1
subs lr, lr, #8
bgt .loop15
/******************************************
@ -498,7 +495,6 @@ mpc_decoder_windowing_D:
mov r8, r8, lsr #16
orr r8, r8, r9, lsl #16 /* (lo>>16) || (hi<<16) */
str r8, [r0], #4 /* store Data */
add r1, r1, #4 /* V++ */
ldmpc regs=r4-r11
#else