Cherry pick vp8 halfpix variance fix

source/config/win/x64/vpx_dsp_rtcd.h

 #ifndef VPX_DSP_RTCD_H_
 #define VPX_DSP_RTCD_H_
 
 #ifdef RTCD_C
 #define RTCD_EXTERN
 #else
 #define RTCD_EXTERN extern
 #endif
 
 /*
@@ skipping 867 matching lines @@
 unsigned int vpx_variance8x4_sse2(const uint8_t *src_ptr, int source_stride, const uint8_t *ref_ptr, int ref_stride, unsigned int *sse);
 #define vpx_variance8x4 vpx_variance8x4_sse2
 
 unsigned int vpx_variance8x8_c(const uint8_t *src_ptr, int source_stride, const uint8_t *ref_ptr, int ref_stride, unsigned int *sse);
 unsigned int vpx_variance8x8_mmx(const uint8_t *src_ptr, int source_stride, const uint8_t *ref_ptr, int ref_stride, unsigned int *sse);
 unsigned int vpx_variance8x8_sse2(const uint8_t *src_ptr, int source_stride, const uint8_t *ref_ptr, int ref_stride, unsigned int *sse);
 #define vpx_variance8x8 vpx_variance8x8_sse2
 
 uint32_t vpx_variance_halfpixvar16x16_h_c(const unsigned char *src_ptr, int source_stride, const unsigned char *ref_ptr, int  ref_stride, uint32_t *sse);
 uint32_t vpx_variance_halfpixvar16x16_h_mmx(const unsigned char *src_ptr, int source_stride, const unsigned char *ref_ptr, int  ref_stride, uint32_t *sse);
-#define vpx_variance_halfpixvar16x16_h vpx_variance_halfpixvar16x16_h_mmx
+uint32_t vpx_variance_halfpixvar16x16_h_sse2(const unsigned char *src_ptr, int source_stride, const unsigned char *ref_ptr, int  ref_stride, uint32_t *sse);
+#define vpx_variance_halfpixvar16x16_h vpx_variance_halfpixvar16x16_h_sse2
 
 uint32_t vpx_variance_halfpixvar16x16_hv_c(const unsigned char *src_ptr, int source_stride, const unsigned char *ref_ptr, int  ref_stride, uint32_t *sse);
 uint32_t vpx_variance_halfpixvar16x16_hv_mmx(const unsigned char *src_ptr, int source_stride, const unsigned char *ref_ptr, int  ref_stride, uint32_t *sse);
-#define vpx_variance_halfpixvar16x16_hv vpx_variance_halfpixvar16x16_hv_mmx
+uint32_t vpx_variance_halfpixvar16x16_hv_sse2(const unsigned char *src_ptr, int source_stride, const unsigned char *ref_ptr, int  ref_stride, uint32_t *sse);
+#define vpx_variance_halfpixvar16x16_hv vpx_variance_halfpixvar16x16_hv_sse2
 
 uint32_t vpx_variance_halfpixvar16x16_v_c(const unsigned char *src_ptr, int source_stride, const unsigned char *ref_ptr, int  ref_stride, uint32_t *sse);
 uint32_t vpx_variance_halfpixvar16x16_v_mmx(const unsigned char *src_ptr, int source_stride, const unsigned char *ref_ptr, int  ref_stride, uint32_t *sse);
-#define vpx_variance_halfpixvar16x16_v vpx_variance_halfpixvar16x16_v_mmx
+uint32_t vpx_variance_halfpixvar16x16_v_sse2(const unsigned char *src_ptr, int source_stride, const unsigned char *ref_ptr, int  ref_stride, uint32_t *sse);
+#define vpx_variance_halfpixvar16x16_v vpx_variance_halfpixvar16x16_v_sse2
 
 void vpx_dsp_rtcd(void);
 
 #ifdef RTCD_C
 #include "vpx_ports/x86.h"
 static void setup_rtcd_internal(void)
 {
     int flags = x86_simd_caps();
 
     (void)flags;
@@ skipping 186 matching lines @@
     vpx_variance64x64 = vpx_variance64x64_sse2;
     if (flags & HAS_AVX2) vpx_variance64x64 = vpx_variance64x64_avx2;
 }
 #endif
 
 #ifdef __cplusplus
 }  // extern "C"
 #endif
 
 #endif