diff options
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/ifcvt.c | 16 |
2 files changed, 21 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2d8e69aa278..03365eac92d 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2005-01-04 Roger Sayle <roger@eyesopen.com> + + * ifcvt.c (find_if_case_1): Avoid creating an empty forwarder block, + if deleting the then-block allows the test-block to fallthru to the + else-block. + 2005-01-04 Andrew Pinski <pinskia@physics.uc.edu> PR c/19152 diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c index 98fbd667a01..75932b37e46 100644 --- a/gcc/ifcvt.c +++ b/gcc/ifcvt.c @@ -2927,7 +2927,21 @@ find_if_case_1 (basic_block test_bb, edge then_edge, edge else_edge) else_bb->global_live_at_start, then_bb->global_live_at_end); - new_bb = redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb), else_bb); + + /* We can avoid creating a new basic block if then_bb is immediately + followed by else_bb, i.e. deleting then_bb allows test_bb to fall + thru to else_bb. */ + + if (then_bb->next_bb == else_bb + && then_bb->prev_bb == test_bb) + { + redirect_edge_succ (FALLTHRU_EDGE (test_bb), else_bb); + new_bb = 0; + } + else + new_bb = redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb), + else_bb); + then_bb_index = then_bb->index; delete_basic_block (then_bb); |