diff options
| author | Michael Sevakis <jethead71@rockbox.org> | 2010-05-11 10:22:23 +0000 |
|---|---|---|
| committer | Michael Sevakis <jethead71@rockbox.org> | 2010-05-11 10:22:23 +0000 |
| commit | 81bfa137b64efd742415eba8e00ae5530e551742 (patch) | |
| tree | 69bdc636dd4c95a892b0713978fd5af10f46841b /apps/dsp_arm.S | |
| parent | 51845b344b90c19c05cb8e49e8a5be1910884c9a (diff) | |
ARM DSP: Get an instruction out of the crossfeed main loop and improve loads and interlocks for stacked vars.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25946 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'apps/dsp_arm.S')
| -rw-r--r-- | apps/dsp_arm.S | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/apps/dsp_arm.S b/apps/dsp_arm.S index d9e05bf248..2a5647d759 100644 --- a/apps/dsp_arm.S +++ b/apps/dsp_arm.S @@ -274,8 +274,9 @@ apply_crossfeed: ldr r1, =crossfeed_data ldmia r1!, { r4-r11 } @ load direct gain and filter data - add r12, r1, #13*4*2 @ calculate end of delay - stmdb sp!, { r0, r12 } @ stack count and end of delay adr + mov r12, r0 @ better to ldm delay + count later + add r0, r1, #13*4*2 @ calculate end of delay + stmdb sp!, { r0, r12 } @ stack end of delay adr and count ldr r0, [r1, #13*4*2] @ fetch current delay line address /* Register usage in loop: @@ -304,15 +305,14 @@ apply_crossfeed: smlal r14, r1, r4, r12 @ acc += gain*x_r[n] str r12, [r0], #4 @ save right input to delay line mov r1, r1, lsl #1 @ fix format + ldmia sp, { r12, r14 } @ fetch delay line end addr and count from stack str r1, [r3], #4 @ save result - ldr r12, [sp, #4] @ fetch delay line end addr from stack cmp r0, r12 @ need to wrap to start of delay? subeq r0, r0, #13*4*2 @ wrap back delay line ptr to start - ldr r1, [sp] @ fetch count from stack - subs r1, r1, #1 @ are we finished? - strne r1, [sp] @ nope, save count back to stack + subs r14, r14, #1 @ are we finished? + strne r14, [sp, #4] @ nope, save count back to stack bne .cfloop @ save data back to struct |