- /* Create the basic block note.
-
- Where we place the note can have a noticeable impact on the generated
- code. Consider this cfg:
-
- E
- |
- 0
- / \
- +->1-->2--->E
- | |
- +--+
-
- If we need to insert an insn on the edge from block 0 to block 1,
- we want to ensure the instructions we insert are outside of any
- loop notes that physically sit between block 0 and block 1. Otherwise
- we confuse the loop optimizer into thinking the loop is a phony. */
-
- if (edge_in->dest != EXIT_BLOCK_PTR
- && PREV_INSN (BB_HEAD (edge_in->dest))
- && NOTE_P (PREV_INSN (BB_HEAD (edge_in->dest)))
- && (NOTE_LINE_NUMBER (PREV_INSN (BB_HEAD (edge_in->dest)))
- == NOTE_INSN_LOOP_BEG)
- && !back_edge_of_syntactic_loop_p (edge_in->dest, edge_in->src))
- before = PREV_INSN (BB_HEAD (edge_in->dest));
- else if (edge_in->dest != EXIT_BLOCK_PTR)