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Add arm assembler for dsp_apply_gain(). Speeds up this routine by 30-40% on PP502x.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25596 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Andree Buschmann 2010-04-11 19:02:43 +00:00
parent 3b1c3881f0
commit efb702dc9b
2 changed files with 40 additions and 0 deletions
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39
apps/dsp_arm.S
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@ -381,3 +381,42 @@ dsp_upsample:
.usend: .usend:
.size dsp_upsample,.usend-dsp_upsample .size dsp_upsample,.usend-dsp_upsample
/****************************************************************************
* void dsp_apply_gain(int count, struct dsp_data *data, int32_t *buf[])
* NOTE: The following code processes two samples at once. When count is odd,
* there is an additional obsolete sample processed, which will not be
* used by the calling functions.
*/
.section .icode, "ax", %progbits
.align 2
.global dsp_apply_gain
.type dsp_apply_gain, %function
dsp_apply_gain:
@ input: r0 = count, r1 = data, r2 = buf[]
stmfd sp!, {r4-r8, lr}
ldr r3, [r1, #4] @ r3 = data->num_channels
ldr r4, [r1, #32] @ r5 = data->gain
.dag_outerloop:
ldr r1, [r2], #4 @ r1 = buf[0] and increment index of buf[]
mov lr, r0 @ lr = r0 = count
.dag_innerloop:
ldmia r1, {r5, r6} @ load r5, r6 from r1
smull r7, r8, r5, r4 @ r5 = FRACMUL_SHL(r5, r4, 8)
mov r8, r8, asl #9
orr r5, r8, r7, lsr #23
smull r7, r8, r6, r4 @ r6 = FRACMUL_SHL(r6, r4, 8)
mov r8, r8, asl #9
orr r6, r8, r7, lsr #23
stmia r1!, {r5, r6} @ save r5, r6 to r1 and increment r1
subs lr, lr, #2
bgt .dag_innerloop @ end of inner loop
subs r3, r3, #1
bgt .dag_outerloop @ end of outer loop
ldmfd sp!, {r4-r8, pc}
.dagend:
.size dsp_apply_gain,.dagend-dsp_apply_gain

1
apps/dsp_asm.h
View file

@ -26,6 +26,7 @@
/* Set the appropriate #defines based on CPU or whatever matters */ /* Set the appropriate #defines based on CPU or whatever matters */
#if defined(CPU_ARM) #if defined(CPU_ARM)
#define DSP_HAVE_ASM_APPLY_GAIN
#define DSP_HAVE_ASM_RESAMPLING #define DSP_HAVE_ASM_RESAMPLING
#define DSP_HAVE_ASM_CROSSFEED #define DSP_HAVE_ASM_CROSSFEED
#define DSP_HAVE_ASM_SOUND_CHAN_MONO #define DSP_HAVE_ASM_SOUND_CHAN_MONO