diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/df-problems.c | 28 | ||||
| -rw-r--r-- | gcc/df.h | 1 |
2 files changed, 22 insertions, 7 deletions
diff --git a/gcc/df-problems.c b/gcc/df-problems.c index 53a1f0d..8fe5858 100644 --- a/gcc/df-problems.c +++ b/gcc/df-problems.c @@ -1917,8 +1917,7 @@ df_mir_alloc (bitmap all_blocks) bitmap_initialize (&bb_info->gen, &problem_data->mir_bitmaps); bitmap_initialize (&bb_info->in, &problem_data->mir_bitmaps); bitmap_initialize (&bb_info->out, &problem_data->mir_bitmaps); - bitmap_set_range (&bb_info->in, 0, DF_REG_SIZE (df)); - bitmap_set_range (&bb_info->out, 0, DF_REG_SIZE (df)); + bb_info->con_visited = false; } } @@ -1941,9 +1940,8 @@ df_mir_reset (bitmap all_blocks) gcc_assert (bb_info); bitmap_clear (&bb_info->in); - bitmap_set_range (&bb_info->in, 0, DF_REG_SIZE (df)); bitmap_clear (&bb_info->out); - bitmap_set_range (&bb_info->out, 0, DF_REG_SIZE (df)); + bb_info->con_visited = false; } } @@ -2021,6 +2019,7 @@ df_mir_confluence_0 (basic_block bb) class df_mir_bb_info *bb_info = df_mir_get_bb_info (bb->index); bitmap_clear (&bb_info->in); + bb_info->con_visited = true; } @@ -2029,12 +2028,27 @@ df_mir_confluence_0 (basic_block bb) static bool df_mir_confluence_n (edge e) { - bitmap op1 = &df_mir_get_bb_info (e->dest->index)->in; - bitmap op2 = &df_mir_get_bb_info (e->src->index)->out; - if (e->flags & EDGE_FAKE) return false; + df_mir_bb_info *src_info = df_mir_get_bb_info (e->src->index); + /* If SRC was not visited yet then we'll and with all-ones which + means no changes. Do not consider DST con_visited by this + operation alone either. */ + if (!src_info->con_visited) + return false; + + df_mir_bb_info *dst_info = df_mir_get_bb_info (e->dest->index); + bitmap op1 = &dst_info->in; + bitmap op2 = &src_info->out; + /* If DEST was not visited yet just copy the SRC bitmap. */ + if (!dst_info->con_visited) + { + dst_info->con_visited = true; + bitmap_copy (op1, op2); + return true; + } + /* A register is must-initialized at the entry of a basic block iff it is must-initialized at the exit of all the predecessors. */ return bitmap_and_into (op1, op2); @@ -929,6 +929,7 @@ public: /* The results of the dataflow problem. */ bitmap_head in; /* At the top of the block. */ bitmap_head out; /* At the bottom of the block. */ + bool con_visited; /* Visited by con_fun_{0,n}. */ }; |