ref: a6a57507fb3dc1f12e5a7b5a500bc65544b38157
dir: /vpx_dsp/ppc/inv_txfm_vsx.h/
#include "vpx_dsp/ppc/types_vsx.h"
void vpx_round_store4x4_vsx(int16x8_t *in, int16x8_t *out, uint8_t *dest,
int stride);
void vpx_idct4_vsx(int16x8_t *in, int16x8_t *out);
void vp9_iadst4_vsx(int16x8_t *in, int16x8_t *out);