those variables are removed from the flow graph so that they can
be computed again.
- 2- Compute dominance frontier and immediate dominators, needed to
- insert PHI nodes and rename the function in dominator tree
- order.
+ 2- Compute dominance frontier, needed to insert PHI nodes and
+ rename the function in dominator tree order.
3- Find and mark all the blocks that define variables
(mark_def_site_blocks).
mark_def_site_blocks ();
- /* Initialize dominance frontier and immediate dominator bitmaps.
- Also count the number of predecessors for each block. Doing so
- can save significant time during PHI insertion for large graphs. */
+ /* Initialize dominance frontier. */
dfs = (bitmap *) xmalloc (last_basic_block * sizeof (bitmap *));
FOR_EACH_BB (bb)
dfs[bb->index] = BITMAP_ALLOC (NULL);