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Two tiny tweaks to some arm asm

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25993 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Nils Wallménius 2010-05-13 09:44:05 +00:00
parent 1940a0b189
commit 889b4a8ce8
2 changed files with 16 additions and 17 deletions
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28
apps/codecs/lib/fft-ffmpeg_arm.h
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@ -5,7 +5,7 @@
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id: $
* $Id$
*
* Copyright (C) 2010 Dave Hooper
*
@ -285,11 +285,10 @@ static inline void fft8( FFTComplex * z )
{
FFTSample temp;
fixed32 * m4 = (fixed32 *)(&(z[4].re));
asm volatile(
"add %[z_ptr], %[z_ptr], #16\n\t" /* point to &z[2].re */
/* read in z[4].re thru z[7].im */
"ldmia %[z4_ptr]!, {r1,r2,r3,r4,r5,r6,r7,r8}\n\t"
"ldmia %[z4_ptr]!, {r1-r8}\n\t"
/* (now points one word past &z[7].im) */
"add r1,r1,r3\n\t"
"sub r3,r1,r3,lsl #1\n\t"
@ -299,32 +298,31 @@ static inline void fft8( FFTComplex * z )
"sub r7,r5,r7\n\t"
"add r5,r6,r8\n\t"
"sub r8,r6,r8\n\t"
"stmdb %[z4_ptr]!, {r7,r8}\n\t" /* write z[7].re,z[7].im straight away */
/* Note, registers r7 & r8 now free */
"sub r6,%[temp],r1\n\t"
"add r1,%[temp],r1\n\t"
"add r2,r2,r5\n\t"
"sub r5,r2,r5,lsl #1\n\t"
"ldmia %[z_ptr],{r7,r8}\n\t" /* load z[2].re and z[2].im */
"add %[temp], %[z_ptr], #16\n\t" /* point to &z[2].re */
"ldmia %[temp],{r7,r8}\n\t" /* load z[2].re and z[2].im */
"add r7,r7,r5\n\t"
"sub r5,r7,r5,lsl #1\n\t"
"add r8,r8,r6\n\t"
"sub r6,r8,r6,lsl #1\n\t"
/* write out z[5].re, z[5].im, z[6].re, z[6].im in one go*/
"stmdb %[z4_ptr]!, {r3,r4,r5,r6}\n\t"
"stmia %[z_ptr],{r7,r8}\n\t" /* write out z[2].re, z[2].im */
"sub %[z_ptr],%[z_ptr], #16\n\t" /* point z_ptr back to &z[0].re */
"stmdb %[z4_ptr]!, {r3-r6}\n\t"
"stmia %[temp],{r7,r8}\n\t" /* write out z[2].re, z[2].im */
"ldmia %[z_ptr],{r7,r8}\n\t" /* load r[0].re, r[0].im */
"add r7,r7,r1\n\t"
"sub r1,r7,r1,lsl #1\n\t"
"add r8,r8,r2\n\t"
"sub r2,r8,r2,lsl #1\n\t"
"stmia %[z_ptr],{r7,r8}\n\t" /* write out z[0].re, z[0].im */
"stmdb %[z4_ptr], {r1,r2}\n\t" /* write out z[4].re, z[4].im */
: [z4_ptr] "+r" (m4), [z_ptr] "+r" (z), [temp] "=r" (temp)
@ -332,7 +330,7 @@ static inline void fft8( FFTComplex * z )
: "r1","r2","r3","r4","r5","r6","r7","r8","memory"
);
}
z++;
TRANSFORM_EQUAL(z,2);
}