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| author | sayle <sayle@138bc75d-0d04-0410-961f-82ee72b054a4> | 2005-01-05 01:45:00 +0000 |
|---|---|---|
| committer | sayle <sayle@138bc75d-0d04-0410-961f-82ee72b054a4> | 2005-01-05 01:45:00 +0000 |
| commit | 12d7523c344cb89785d92073037c062f3b487b15 (patch) | |
| tree | f80c754142d8d7426764371d9c1effdfea791755 /gcc/ifcvt.c | |
| parent | 67be63e60f12049d0b2105a14a94be485b7bfdb4 (diff) | |
| download | gcc-12d7523c344cb89785d92073037c062f3b487b15.tar.gz | |
* 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.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@92919 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/ifcvt.c')
| -rw-r--r-- | gcc/ifcvt.c | 16 |
1 files changed, 15 insertions, 1 deletions
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); |