diff --git a/vp9/encoder/x86/vp9_variance_mmx.c b/vp9/encoder/x86/vp9_variance_mmx.c
index ae2f976af..ce1c83297 100644
--- a/vp9/encoder/x86/vp9_variance_mmx.c
+++ b/vp9/encoder/x86/vp9_variance_mmx.c
@@ -12,141 +12,92 @@
 #include "vp9/encoder/vp9_variance.h"
 #include "vpx_ports/mem.h"
 
-extern unsigned int vp9_get8x8var_mmx
-(
-  const unsigned char *src_ptr,
-  int  source_stride,
-  const unsigned char *ref_ptr,
-  int  recon_stride,
-  unsigned int *SSE,
-  int *Sum
-);
-extern unsigned int vp9_get4x4var_mmx
-(
-  const unsigned char *src_ptr,
-  int  source_stride,
-  const unsigned char *ref_ptr,
-  int  recon_stride,
-  unsigned int *SSE,
-  int *Sum
-);
+unsigned int vp9_get8x8var_mmx(const uint8_t *src, int src_stride,
+                               const uint8_t *ref, int ref_stride,
+                               unsigned int *sse, int *sum);
 
-unsigned int vp9_variance4x4_mmx(
-  const unsigned char *src_ptr,
-  int  source_stride,
-  const unsigned char *ref_ptr,
-  int  recon_stride,
-  unsigned int *sse) {
-  unsigned int var;
-  int avg;
+unsigned int vp9_get4x4var_mmx(const uint8_t *src, int src_stride,
+                               const uint8_t *ref, int ref_stride,
+                               unsigned int *SSE, int *sum);
 
-  vp9_get4x4var_mmx(src_ptr, source_stride, ref_ptr, recon_stride, &var, &avg);
-  *sse = var;
-  return (var - (((unsigned int)avg * avg) >> 4));
+unsigned int vp9_variance4x4_mmx(const uint8_t *src, int src_stride,
+                                 const uint8_t *ref, int ref_stride,
+                                 unsigned int *sse) {
+  int sum;
+  vp9_get4x4var_mmx(src, src_stride, ref, ref_stride, sse, &sum);
+  return *sse - (((unsigned int)sum * sum) >> 4);
 }
 
-unsigned int vp9_variance8x8_mmx(
-  const unsigned char *src_ptr,
-  int  source_stride,
-  const unsigned char *ref_ptr,
-  int  recon_stride,
-  unsigned int *sse) {
-  unsigned int var;
-  int avg;
-
-  vp9_get8x8var_mmx(src_ptr, source_stride, ref_ptr, recon_stride, &var, &avg);
-  *sse = var;
-
-  return (var - (((unsigned int)avg * avg) >> 6));
+unsigned int vp9_variance8x8_mmx(const uint8_t *src, int src_stride,
+                                 const uint8_t *ref, int ref_stride,
+                                 unsigned int *sse) {
+  int sum;
+  vp9_get8x8var_mmx(src, src_stride, ref, ref_stride, sse, &sum);
+  return *sse - (((unsigned int)sum * sum) >> 6);
 }
 
-unsigned int vp9_mse16x16_mmx(
-  const unsigned char *src_ptr,
-  int  source_stride,
-  const unsigned char *ref_ptr,
-  int  recon_stride,
-  unsigned int *sse) {
-  unsigned int sse0, sse1, sse2, sse3, var;
+unsigned int vp9_mse16x16_mmx(const uint8_t *src, int src_stride,
+                              const uint8_t *ref, int ref_stride,
+                              unsigned int *sse) {
+  unsigned int sse0, sse1, sse2, sse3;
   int sum0, sum1, sum2, sum3;
 
+  vp9_get8x8var_mmx(src, src_stride, ref, ref_stride, &sse0, &sum0);
+  vp9_get8x8var_mmx(src + 8, src_stride, ref + 8, ref_stride, &sse1, &sum1);
+  vp9_get8x8var_mmx(src + 8 * src_stride, src_stride,
+                    ref + 8 * ref_stride, ref_stride, &sse2, &sum2);
+  vp9_get8x8var_mmx(src + 8 * src_stride + 8, src_stride,
+                    ref + 8 * ref_stride + 8, ref_stride, &sse3, &sum3);
 
-  vp9_get8x8var_mmx(src_ptr, source_stride, ref_ptr, recon_stride, &sse0,
-                    &sum0);
-  vp9_get8x8var_mmx(src_ptr + 8, source_stride, ref_ptr + 8, recon_stride,
-                    &sse1, &sum1);
-  vp9_get8x8var_mmx(src_ptr + 8 * source_stride, source_stride,
-                    ref_ptr + 8 * recon_stride, recon_stride, &sse2, &sum2);
-  vp9_get8x8var_mmx(src_ptr + 8 * source_stride + 8, source_stride,
-                    ref_ptr + 8 * recon_stride + 8, recon_stride, &sse3, &sum3);
-
-  var = sse0 + sse1 + sse2 + sse3;
-  *sse = var;
-  return var;
+  *sse = sse0 + sse1 + sse2 + sse3;
+  return *sse;
 }
 
 
-unsigned int vp9_variance16x16_mmx(
-  const unsigned char *src_ptr,
-  int  source_stride,
-  const unsigned char *ref_ptr,
-  int  recon_stride,
-  unsigned int *sse) {
-  unsigned int sse0, sse1, sse2, sse3, var;
-  int sum0, sum1, sum2, sum3, avg;
+unsigned int vp9_variance16x16_mmx(const uint8_t *src, int src_stride,
+                                   const uint8_t *ref, int ref_stride,
+                                   unsigned int *sse) {
+  unsigned int sse0, sse1, sse2, sse3;
+  int sum0, sum1, sum2, sum3, sum;
 
-  vp9_get8x8var_mmx(src_ptr, source_stride, ref_ptr, recon_stride, &sse0,
-                    &sum0);
-  vp9_get8x8var_mmx(src_ptr + 8, source_stride, ref_ptr + 8, recon_stride,
-                    &sse1, &sum1);
-  vp9_get8x8var_mmx(src_ptr + 8 * source_stride, source_stride,
-                    ref_ptr + 8 * recon_stride, recon_stride, &sse2, &sum2);
-  vp9_get8x8var_mmx(src_ptr + 8 * source_stride + 8, source_stride,
-                    ref_ptr + 8 * recon_stride + 8, recon_stride, &sse3, &sum3);
+  vp9_get8x8var_mmx(src, src_stride, ref, ref_stride, &sse0, &sum0);
+  vp9_get8x8var_mmx(src + 8, src_stride, ref + 8, ref_stride, &sse1, &sum1);
+  vp9_get8x8var_mmx(src + 8 * src_stride, src_stride,
+                    ref + 8 * ref_stride, ref_stride, &sse2, &sum2);
+  vp9_get8x8var_mmx(src + 8 * src_stride + 8, src_stride,
+                    ref + 8 * ref_stride + 8, ref_stride, &sse3, &sum3);
 
-  var = sse0 + sse1 + sse2 + sse3;
-  avg = sum0 + sum1 + sum2 + sum3;
-  *sse = var;
-  return (var - (((unsigned int)avg * avg) >> 8));
+  *sse = sse0 + sse1 + sse2 + sse3;
+  sum = sum0 + sum1 + sum2 + sum3;
+  return *sse - (((unsigned int)sum * sum) >> 8);
 }
 
-unsigned int vp9_variance16x8_mmx(
-  const unsigned char *src_ptr,
-  int  source_stride,
-  const unsigned char *ref_ptr,
-  int  recon_stride,
-  unsigned int *sse) {
-  unsigned int sse0, sse1, var;
-  int sum0, sum1, avg;
+unsigned int vp9_variance16x8_mmx(const uint8_t *src, int src_stride,
+                                  const uint8_t *ref, int ref_stride,
+                                  unsigned int *sse) {
+  unsigned int sse0, sse1;
+  int sum0, sum1, sum;
 
-  vp9_get8x8var_mmx(src_ptr, source_stride, ref_ptr, recon_stride, &sse0,
-                    &sum0);
-  vp9_get8x8var_mmx(src_ptr + 8, source_stride, ref_ptr + 8, recon_stride,
-                    &sse1, &sum1);
+  vp9_get8x8var_mmx(src, src_stride, ref, ref_stride, &sse0, &sum0);
+  vp9_get8x8var_mmx(src + 8, src_stride, ref + 8, ref_stride, &sse1, &sum1);
 
-  var = sse0 + sse1;
-  avg = sum0 + sum1;
-  *sse = var;
-  return (var - (((unsigned int)avg * avg) >> 7));
+  *sse = sse0 + sse1;
+  sum = sum0 + sum1;
+  return *sse - (((unsigned int)sum * sum) >> 7);
 }
 
 
-unsigned int vp9_variance8x16_mmx(
-  const unsigned char *src_ptr,
-  int  source_stride,
-  const unsigned char *ref_ptr,
-  int  recon_stride,
-  unsigned int *sse) {
-  unsigned int sse0, sse1, var;
-  int sum0, sum1, avg;
+unsigned int vp9_variance8x16_mmx(const uint8_t *src, int src_stride,
+                                  const uint8_t *ref, int ref_stride,
+                                  unsigned int *sse) {
+  unsigned int sse0, sse1;
+  int sum0, sum1, sum;
 
-  vp9_get8x8var_mmx(src_ptr, source_stride, ref_ptr, recon_stride, &sse0,
-                    &sum0);
-  vp9_get8x8var_mmx(src_ptr + 8 * source_stride, source_stride,
-                    ref_ptr + 8 * recon_stride, recon_stride, &sse1, &sum1);
+  vp9_get8x8var_mmx(src, src_stride, ref, ref_stride, &sse0, &sum0);
+  vp9_get8x8var_mmx(src + 8 * src_stride, src_stride,
+                    ref + 8 * ref_stride, ref_stride, &sse1, &sum1);
 
-  var = sse0 + sse1;
-  avg = sum0 + sum1;
-  *sse = var;
-
-  return (var - (((unsigned int)avg * avg) >> 7));
+  *sse = sse0 + sse1;
+  sum = sum0 + sum1;
+  return *sse - (((unsigned int)sum * sum) >> 7);
 }