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Fixed a bug in the C code in a filterbank function in iSAC-fix, and further optimized ARM code.

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The bug was introduced in the last CL during optimization.

With the new inine ARM assembly, the resulted assembly code of the loop is 28 instructions, compared to 47 lines by the original.

The optimized (with WEBRTC_ARCH_ARM_V7A defined in This file) and un-optimized code (with WEBRTC_ARCH_ARM_V7A not defined in This file) are bit-exact.
Review URL: https://webrtc-codereview.appspot.com/748004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@2651 4adac7df-926f-26a2-2b94-8c16560cd09d
This commit is contained in:
kma@webrtc.org 2012-08-22 05:13:09 +00:00
parent d6fcf7f0da
commit d81d906adf
1 changed files with 25 additions and 23 deletions

34
src/modules/audio_coding/codecs/isac/fix/source/filterbanks.c

@ -60,38 +60,40 @@ static void HighpassFilterFixDec32(
WebRtc_Word32 a2 = 0, b2 = 0;
WebRtc_Word32 state0 = state[0];
WebRtc_Word32 state1 = state[1];
#ifdef WEBRTC_ARCH_ARM_V7A
WebRtc_Word32* coeff_ptr = (WebRtc_Word32*) coeff;
#endif
for (k=0; k<len; k++) {
in = (WebRtc_Word32)io[k];
#ifdef WEBRTC_ARCH_ARM_V7A
{
int tmp_coeff = 0;
__asm __volatile(
"smmul %[a2], %[coeff01], %[state0]\n\t"
"smmul %[b2], %[coeff23], %[state1]\n\t"
"smmul %[a1], %[coeff45], %[state0]\n\t"
"smmul %[b1], %[coeff67], %[state1]\n\t"
"ldr %[tmp_coeff], [%[coeff]]\n\t"
"smmulr %[a2], %[tmp_coeff], %[state0]\n\t"
"ldr %[tmp_coeff], [%[coeff], #4]\n\t"
"smmulr %[b2], %[tmp_coeff], %[state1]\n\t"
"ldr %[tmp_coeff], [%[coeff], #8]\n\t"
"smmulr %[a1], %[tmp_coeff], %[state0]\n\t"
"ldr %[tmp_coeff], [%[coeff], #12]\n\t"
"smmulr %[b1], %[tmp_coeff], %[state1]\n\t"
:[a2]"+r"(a2),
[b2]"+r"(b2),
[a1]"+r"(a1),
[b1]"+r"(b1)
:[coeff01]"r"(coeff_ptr[0]),
[coeff23]"r"(coeff_ptr[1]),
[coeff45]"r"(coeff_ptr[2]),
[coeff67]"r"(coeff_ptr[3]),
[b1]"+r"(b1),
[tmp_coeff]"+r"(tmp_coeff)
:[coeff]"r"(coeff),
[state0]"r"(state0),
[state1]"r"(state1)
);
}
#else
/* Q35 * Q4 = Q39 ; shift 32 bit => Q7 */
a1 = WEBRTC_SPL_MUL_32_32_RSFT32(coeff[5], coeff[4], state[0]);
b1 = WEBRTC_SPL_MUL_32_32_RSFT32(coeff[7], coeff[6], state[1]);
a1 = WEBRTC_SPL_MUL_32_32_RSFT32(coeff[5], coeff[4], state0);
b1 = WEBRTC_SPL_MUL_32_32_RSFT32(coeff[7], coeff[6], state1);
/* Q30 * Q4 = Q34 ; shift 32 bit => Q2 */
a2 = WEBRTC_SPL_MUL_32_32_RSFT32(coeff[1], coeff[0], state[0]);
b2 = WEBRTC_SPL_MUL_32_32_RSFT32(coeff[3], coeff[2], state[1]);
a2 = WEBRTC_SPL_MUL_32_32_RSFT32(coeff[1], coeff[0], state0);
b2 = WEBRTC_SPL_MUL_32_32_RSFT32(coeff[3], coeff[2], state1);
#endif
c = ((WebRtc_Word32)in) + WEBRTC_SPL_RSHIFT_W32(a1+b1, 7); // Q0