search for: smlawb

Hi I want to port speex to my pocket PC iPAQ1945 which has a Samsung processor 2410, an ARM9-based processor. I would like to write the specific optimized code for this chip. I had some experience at DSP chip and fixed-point coding but know nothing about embedded system and ARM. Could someone tell me some hint how to write optimized code for this pocket PC. If you can give me some links that will

...t;%r"(b<<1),"r"(a) + ); + return res; +} + + +/** 16x32 multiply-add, followed by a 15-bit shift right. Results fits in 32 bits */ +#undef MAC16_32_Q15 +static inline opus_val32 MAC16_32_Q15(opus_val32 c, opus_val16 a, opus_val32 b) +{ + int res; + __asm__( + "smlawb %0, %1, %2, %3;\n" + : "=&r"(res) + : "%r"(b<<1),"r"(a), "r"(c) + ); + return res; +} + +/** 16x16 multiply-add where the result fits in 32 bits */ +#undef MAC16_16 +static inline opus_val32 MAC16_16(opus_val32 c, opus_val16 a,...

...ming you have gcc, you can already compile with --enable-arm5e-asm > and get good results. Right now, many places use ARM4 assembly even on > ARM5E, so if you want even better results, you can rewrite those. The > main instructions you'll want to use are smulbb, smlabb, smulwb and > smlawb, which aren't present in ARM4 and are usually more efficient than > mul, smull and mla. > > Jean-Marc >

Hello Greg If money isn't a problem Intel has an optimized compiler for eVC and XScale processors http://www.intel.com/software/products/compilers/techtopics/PCA_Optimization_WP.pdf If you have any luck getting the eVC compiler closer to realtime I'd really like to know. I'm still far from realtime when using Speex 1.1.3 on a HP iPAQ (Intel pxa255). Best regards Bjoern D.