Refactor super_block_uvrd function to remove goto statement

Use return value 0/1 as indicator of the validity of the rate-
distortion cost.

Change-Id: I6244126fbf03472cebcba4f177a6cd329fae4743

vp9/encoder/vp9_rdopt.c

@@ -1112,21 +1112,24 @@ static int64_t rd_pick_intra_sby_mode(VP9_COMP *cpi, MACROBLOCK *x,
   return best_rd;
 }
 
-static void super_block_uvrd(const VP9_COMP *cpi, MACROBLOCK *x,
-                             int *rate, int64_t *distortion, int *skippable,
-                             int64_t *sse, BLOCK_SIZE bsize,
-                             int64_t ref_best_rd) {
+// Return value 0: early termination triggered, no valid rd cost available;
+//              1: rd cost values are valid.
+static int super_block_uvrd(const VP9_COMP *cpi, MACROBLOCK *x,
+                            int *rate, int64_t *distortion, int *skippable,
+                            int64_t *sse, BLOCK_SIZE bsize,
+                            int64_t ref_best_rd) {
   MACROBLOCKD *const xd = &x->e_mbd;
   MB_MODE_INFO *const mbmi = &xd->mi[0].src_mi->mbmi;
   const TX_SIZE uv_tx_size = get_uv_tx_size(mbmi, &xd->plane[1]);
   int plane;
   int pnrate = 0, pnskip = 1;
   int64_t pndist = 0, pnsse = 0;
+  int is_cost_valid = 1;
 
   if (ref_best_rd < 0)
-    goto term;
+    is_cost_valid = 0;
 
-  if (is_inter_block(mbmi)) {
+  if (is_inter_block(mbmi) && is_cost_valid) {
     int plane;
     for (plane = 1; plane < MAX_MB_PLANE; ++plane)
       vp9_subtract_plane(x, bsize, plane);
@@ -1137,25 +1140,27 @@ static void super_block_uvrd(const VP9_COMP *cpi, MACROBLOCK *x,
   *sse = 0;
   *skippable = 1;
 
-  for (plane = 1; plane < MAX_MB_PLANE; ++plane) {
+  for (plane = 1; plane < MAX_MB_PLANE && is_cost_valid; ++plane) {
     txfm_rd_in_plane(x, &pnrate, &pndist, &pnskip, &pnsse,
                      ref_best_rd, plane, bsize, uv_tx_size,
                      cpi->sf.use_fast_coef_costing);
     if (pnrate == INT_MAX)
-      goto term;
+      is_cost_valid = 0;
     *rate += pnrate;
     *distortion += pndist;
     *sse += pnsse;
     *skippable &= pnskip;
   }
-  return;
-
-  term:
-  *rate = INT_MAX;
-  *distortion = INT64_MAX;
-  *sse = INT64_MAX;
-  *skippable = 0;
-  return;
+
+  if (!is_cost_valid) {
+    // reset cost value
+    *rate = INT_MAX;
+    *distortion = INT64_MAX;
+    *sse = INT64_MAX;
+    *skippable = 0;
+  }
+
+  return is_cost_valid;
 }
 
 static int64_t rd_pick_intra_sbuv_mode(VP9_COMP *cpi, MACROBLOCK *x,
@@ -1177,9 +1182,8 @@ static int64_t rd_pick_intra_sbuv_mode(VP9_COMP *cpi, MACROBLOCK *x,
 
     xd->mi[0].src_mi->mbmi.uv_mode = mode;
 
-    super_block_uvrd(cpi, x, &this_rate_tokenonly,
-                     &this_distortion, &s, &this_sse, bsize, best_rd);
-    if (this_rate_tokenonly == INT_MAX)
+    if (!super_block_uvrd(cpi, x, &this_rate_tokenonly,
+                          &this_distortion, &s, &this_sse, bsize, best_rd))
       continue;
     this_rate = this_rate_tokenonly +
                 cpi->intra_uv_mode_cost[cpi->common.frame_type][mode];
@@ -2671,9 +2675,8 @@ static int64_t handle_inter_mode(VP9_COMP *cpi, MACROBLOCK *x,
     rdcosty = RDCOST(x->rdmult, x->rddiv, *rate2, *distortion);
     rdcosty = MIN(rdcosty, RDCOST(x->rdmult, x->rddiv, 0, *psse));
 
-    super_block_uvrd(cpi, x, rate_uv, &distortion_uv, &skippable_uv, &sseuv,
-                     bsize, ref_best_rd - rdcosty);
-    if (*rate_uv == INT_MAX) {
+    if (!super_block_uvrd(cpi, x, rate_uv, &distortion_uv, &skippable_uv,
+                          &sseuv, bsize, ref_best_rd - rdcosty)) {
       *rate2 = INT_MAX;
       *distortion = INT64_MAX;
       restore_dst_buf(xd, orig_dst, orig_dst_stride);
@@ -3945,10 +3948,10 @@ void vp9_rd_pick_inter_mode_sub8x8(VP9_COMP *cpi, MACROBLOCK *x,
         vp9_build_inter_predictors_sbuv(&x->e_mbd, mi_row, mi_col,
                                         BLOCK_8X8);
         vpx_memset(x->skip_txfm, 0, sizeof(x->skip_txfm));
-        super_block_uvrd(cpi, x, &rate_uv, &distortion_uv, &uv_skippable,
-                         &uv_sse, BLOCK_8X8, tmp_best_rdu);
-        if (rate_uv == INT_MAX)
+        if (!super_block_uvrd(cpi, x, &rate_uv, &distortion_uv, &uv_skippable,
+                              &uv_sse, BLOCK_8X8, tmp_best_rdu))
           continue;
+
         rate2 += rate_uv;
         distortion2 += distortion_uv;
         skippable = skippable && uv_skippable;