Update audio code to use size_t more correctly,

webrtc/common_audio/signal_processing/vector_scaling_operations_mips.c

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 
 /*
  * This file contains implementations of the functions
  * WebRtcSpl_ScaleAndAddVectorsWithRound_mips()
  */
 
 #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
 
 int WebRtcSpl_ScaleAndAddVectorsWithRound_mips(const int16_t* in_vector1,
                                                int16_t in_vector1_scale,
                                                const int16_t* in_vector2,
                                                int16_t in_vector2_scale,
                                                int right_shifts,
                                                int16_t* out_vector,
-                                               int length) {
+                                               size_t length) {
   int16_t r0 = 0, r1 = 0;
   int16_t *in1 = (int16_t*)in_vector1;
   int16_t *in2 = (int16_t*)in_vector2;
   int16_t *out = out_vector;
-  int i = 0, value32 = 0;
+  size_t i = 0;
+  int value32 = 0;
 
   if (in_vector1 == NULL || in_vector2 == NULL || out_vector == NULL ||
-      length <= 0 || right_shifts < 0) {
+      length == 0 || right_shifts < 0) {
     return -1;
   }
   for (i = 0; i < length; i++) {
     __asm __volatile (
       "lh         %[r0],          0(%[in1])                               \n\t"
       "lh         %[r1],          0(%[in2])                               \n\t"
       "mult       %[r0],          %[in_vector1_scale]                     \n\t"
       "madd       %[r1],          %[in_vector2_scale]                     \n\t"
       "extrv_r.w  %[value32],     $ac0,               %[right_shifts]     \n\t"
       "addiu      %[in1],         %[in1],             2                   \n\t"
       "addiu      %[in2],         %[in2],             2                   \n\t"
       "sh         %[value32],     0(%[out])                               \n\t"
       "addiu      %[out],         %[out],             2                   \n\t"
       : [value32] "=&r" (value32), [out] "+r" (out), [in1] "+r" (in1),
         [in2] "+r" (in2), [r0] "=&r" (r0), [r1] "=&r" (r1)
       : [in_vector1_scale] "r" (in_vector1_scale),
         [in_vector2_scale] "r" (in_vector2_scale),
         [right_shifts] "r" (right_shifts)
       : "hi", "lo", "memory"
     );
   }
   return 0;
 }