MIPS optimizations for ISAC (patch #2)

Implemented functions:
- WebRtcIsacfix_CalculateResidualEnergy
- WebRtcIsacfix_Spec2Time
- WebRtcIsacfix_Time2Spec
- WebRtcIsacfix_HighpassFilterFixDec32
- WebRtcIsacfix_PCorr2Q32

Gain achieved: aprox. further 5% on top of patch#1 on ISAC encoding path.
The optimizations are bit-exact to the C code, with the excception of the
MIPS DSPr2 variant of the WebRtcIsacfix_Time2Spec function (the accuracy of
the WebRtcIsacfix_Time2Spec MIPS DSPr2 variant is same or better than C
variant). Code verification and improvement achieved have been determined
using the iSACFixtest application.

R=andrew@webrtc.org, tina.legrand@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/19749004

Patch from Ljubomir Papuga <lpapuga@mips.com>.

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@6749 4adac7df-926f-26a2-2b94-8c16560cd09d

1 files changed, 9 insertions, 0 deletions

diff --git a/modules/audio_coding/codecs/isac/fix/source/lpc_masking_model.h b/modules/audio_coding/codecs/isac/fix/source/lpc_masking_model.h
index 72e0cfc4..1270c142 100644
--- a/modules/audio_coding/codecs/isac/fix/source/lpc_masking_model.h
+++ b/modules/audio_coding/codecs/isac/fix/source/lpc_masking_model.h
@@ -62,6 +62,15 @@ int32_t WebRtcIsacfix_CalculateResidualEnergyNeon(int lpc_order,
                                                   int* q_val_residual_energy);
 #endif
 
+#if defined(MIPS_DSP_R2_LE)
+int32_t WebRtcIsacfix_CalculateResidualEnergyMIPS(int lpc_order,
+                                                  int32_t q_val_corr,
+                                                  int q_val_polynomial,
+                                                  int16_t* a_polynomial,
+                                                  int32_t* corr_coeffs,
+                                                  int* q_val_residual_energy);
+#endif
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif