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author | Rafaël Carré <rafael.carre@gmail.com> | 2010-06-11 14:04:48 +0000 |
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committer | Rafaël Carré <rafael.carre@gmail.com> | 2010-06-11 14:04:48 +0000 |
commit | d5a27c2fb1d653bb133a57acacc06b9efdc3ce4c (patch) | |
tree | 96a2a4b594608362ce372e66a89724ed4329bdf7 | |
parent | 9a2b1d612cd887c47254015b1721517494f12ab9 (diff) | |
download | rockbox-d5a27c2fb1d653bb133a57acacc06b9efdc3ce4c.tar.gz rockbox-d5a27c2fb1d653bb133a57acacc06b9efdc3ce4c.zip |
pcm as3525v1: revert 26761 to use faster ASM code
Fix the asm constraints to mark the left output variable as earlyclobber
Thanks to amiconn
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26777 a1c6a512-1295-4272-9138-f99709370657
-rw-r--r-- | firmware/target/arm/as3525/pcm-as3525.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/firmware/target/arm/as3525/pcm-as3525.c b/firmware/target/arm/as3525/pcm-as3525.c index 20c34bba36..8c5bb67076 100644 --- a/firmware/target/arm/as3525/pcm-as3525.c +++ b/firmware/target/arm/as3525/pcm-as3525.c | |||
@@ -263,7 +263,7 @@ static inline void mono2stereo(int16_t *end) | |||
263 | { | 263 | { |
264 | if(audio_channels != 1) /* only for microphone */ | 264 | if(audio_channels != 1) /* only for microphone */ |
265 | return; | 265 | return; |
266 | 266 | #if 0 | |
267 | /* load pointer in a register and avoid updating it in each loop */ | 267 | /* load pointer in a register and avoid updating it in each loop */ |
268 | register int16_t *samples = mono_samples; | 268 | register int16_t *samples = mono_samples; |
269 | 269 | ||
@@ -273,6 +273,19 @@ static inline void mono2stereo(int16_t *end) | |||
273 | } while(samples != end); | 273 | } while(samples != end); |
274 | 274 | ||
275 | mono_samples = samples; /* update pointer */ | 275 | mono_samples = samples; /* update pointer */ |
276 | #else | ||
277 | /* gcc doesn't use pre indexing : let's save 1 cycle */ | ||
278 | int16_t left; | ||
279 | asm ( | ||
280 | "1: ldrh %0, [%1], #2 \n" // load 1 sample of the left-channel | ||
281 | " strh %0, [%1], #2 \n" // copy it in the right-channel | ||
282 | " cmp %1, %2 \n" // are we finished? | ||
283 | " bne 1b \n" | ||
284 | : "=&r"(left), "+r"(mono_samples) | ||
285 | : "r"(end) | ||
286 | : "memory" | ||
287 | ); | ||
288 | #endif /* C / ASM */ | ||
276 | } | 289 | } |
277 | #endif /* CONFIG_CPU == AS3525 */ | 290 | #endif /* CONFIG_CPU == AS3525 */ |
278 | 291 | ||