Move index check before array access

This lets us run code with -fsanitize=bounds.

Bug: b/15471229

Change-Id: I5961ef43d21f04a0dc9e8bf7280dc27eb0a62094

diff --git a/vp9/encoder/vp9_encodeframe.c b/vp9/encoder/vp9_encodeframe.c
index 13f9a1f..dd2e069 100644 (file)
--- a/vp9/encoder/vp9_encodeframe.c
+++ b/vp9/encoder/vp9_encodeframe.c
@@ -3766,9 +3766,6 @@ static int wiener_var_segment(VP9_COMP *cpi, BLOCK_SIZE bsize, int mi_row,
 static int get_rdmult_delta(VP9_COMP *cpi, BLOCK_SIZE bsize, int mi_row,
                             int mi_col, int orig_rdmult) {
   const int gf_group_index = cpi->twopass.gf_group.index;
-  TplDepFrame *tpl_frame = &cpi->tpl_stats[gf_group_index];
-  TplDepStats *tpl_stats = tpl_frame->tpl_stats_ptr;
-  int tpl_stride = tpl_frame->stride;
   int64_t intra_cost = 0;
   int64_t mc_dep_cost = 0;
   int mi_wide = num_8x8_blocks_wide_lookup[bsize];
@@ -3779,12 +3776,19 @@ static int get_rdmult_delta(VP9_COMP *cpi, BLOCK_SIZE bsize, int mi_row,
   int count = 0;
   double r0, rk, beta;
 
+  TplDepFrame *tpl_frame;
+  TplDepStats *tpl_stats;
+  int tpl_stride;
+
+  if (gf_group_index >= MAX_ARF_GOP_SIZE) return orig_rdmult;
+  tpl_frame = &cpi->tpl_stats[gf_group_index];
+
   if (tpl_frame->is_valid == 0) return orig_rdmult;
+  tpl_stats = tpl_frame->tpl_stats_ptr;
+  tpl_stride = tpl_frame->stride;
 
   if (cpi->twopass.gf_group.layer_depth[gf_group_index] > 1) return orig_rdmult;
 
-  if (gf_group_index >= MAX_ARF_GOP_SIZE) return orig_rdmult;
-
   for (row = mi_row; row < mi_row + mi_high; ++row) {
     for (col = mi_col; col < mi_col + mi_wide; ++col) {
       TplDepStats *this_stats = &tpl_stats[row * tpl_stride + col];