diff options
Diffstat (limited to 'gcc/lcm.c')
| -rw-r--r-- | gcc/lcm.c | 22 |
1 files changed, 22 insertions, 0 deletions
@@ -1029,6 +1029,7 @@ optimize_mode_switching (file) int i, j; int n_entities; int max_num_modes = 0; + bool emited = false; #ifdef NORMAL_MODE /* Increment n_basic_blocks before allocating bb_info. */ @@ -1239,10 +1240,16 @@ optimize_mode_switching (file) mode_set = gen_sequence (); end_sequence (); + /* Do not bother to insert empty sequence. */ + if (GET_CODE (mode_set) == SEQUENCE + && !XVECLEN (mode_set, 0)) + continue; + /* If this is an abnormal edge, we'll insert at the end of the previous block. */ if (eg->flags & EDGE_ABNORMAL) { + emited = true; if (GET_CODE (src_bb->end) == JUMP_INSN) emit_insn_before (mode_set, src_bb->end); /* It doesn't make sense to switch to normal mode @@ -1313,10 +1320,16 @@ optimize_mode_switching (file) mode_set = gen_sequence (); end_sequence (); + /* Do not bother to insert empty sequence. */ + if (GET_CODE (mode_set) == SEQUENCE + && !XVECLEN (mode_set, 0)) + continue; + /* If this is an abnormal edge, we'll insert at the end of the previous block. */ if (eg->flags & EDGE_ABNORMAL) { + emited = true; if (GET_CODE (eg->src->end) == JUMP_INSN) emit_insn_before (mode_set, eg->src->end); else if (GET_CODE (eg->src->end) == INSN) @@ -1349,6 +1362,12 @@ optimize_mode_switching (file) mode_set = gen_sequence (); end_sequence (); + /* Do not bother to insert empty sequence. */ + if (GET_CODE (mode_set) == SEQUENCE + && !XVECLEN (mode_set, 0)) + continue; + + emited = true; if (GET_CODE (ptr->insn_ptr) == NOTE && (NOTE_LINE_NUMBER (ptr->insn_ptr) == NOTE_INSN_BASIC_BLOCK)) @@ -1376,6 +1395,9 @@ optimize_mode_switching (file) if (need_commit) commit_edge_insertions (); + if (!need_commit && !emited) + return 0; + /* Ideally we'd figure out what blocks were affected and start from there, but this is enormously complicated by commit_edge_insertions, which would screw up any indicies we'd collected, and also need to |