diff options
Diffstat (limited to 'gcc/tree-cfgcleanup.c')
| -rw-r--r-- | gcc/tree-cfgcleanup.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/gcc/tree-cfgcleanup.c b/gcc/tree-cfgcleanup.c index 922ae0d82a6..b5c384b902c 100644 --- a/gcc/tree-cfgcleanup.c +++ b/gcc/tree-cfgcleanup.c @@ -308,14 +308,24 @@ tree_forwarder_block_p (basic_block bb, bool phi_wanted) if (current_loops) { basic_block dest; - /* Protect loop latches, headers and preheaders. */ + /* Protect loop headers. */ if (bb->loop_father->header == bb) return false; - dest = EDGE_SUCC (bb, 0)->dest; + dest = EDGE_SUCC (bb, 0)->dest; + /* Protect loop preheaders and latches if requested. */ if (dest->loop_father->header == dest) - return false; + { + if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) + && bb->loop_father->header != dest) + return false; + + if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES) + && bb->loop_father->header == dest) + return false; + } } + return true; } @@ -497,6 +507,11 @@ remove_forwarder_block (basic_block bb) set_immediate_dominator (CDI_DOMINATORS, dest, dom); } + /* Adjust latch infomation of BB's parent loop as otherwise + the cfg hook has a hard time not to kill the loop. */ + if (current_loops && bb->loop_father->latch == bb) + bb->loop_father->latch = dest; + /* And kill the forwarder block. */ delete_basic_block (bb); |