diff options
Diffstat (limited to 'gcc/cfgcleanup.c')
| -rw-r--r-- | gcc/cfgcleanup.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/gcc/cfgcleanup.c b/gcc/cfgcleanup.c index b6a7f0cc4ea..74a2256b5e2 100644 --- a/gcc/cfgcleanup.c +++ b/gcc/cfgcleanup.c @@ -1,6 +1,6 @@ /* Control flow optimization code for GNU compiler. Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, - 1999, 2000, 2001 Free Software Foundation, Inc. + 1999, 2000, 2001, 2002 Free Software Foundation, Inc. This file is part of GCC. @@ -1751,22 +1751,33 @@ try_optimize_cfg (mode) static bool delete_unreachable_blocks () { - int i; + int i, j; bool changed = false; find_unreachable_blocks (); - /* Delete all unreachable basic blocks. Count down so that we - don't interfere with the block renumbering that happens in - flow_delete_block. */ + /* Delete all unreachable basic blocks. Do compaction concurrently, + as otherwise we can wind up with O(N^2) behaviour here when we + have oodles of dead code. */ - for (i = n_basic_blocks - 1; i >= 0; --i) + for (i = j = 0; i < n_basic_blocks; ++i) { basic_block b = BASIC_BLOCK (i); if (!(b->flags & BB_REACHABLE)) - flow_delete_block (b), changed = true; + { + flow_delete_block_noexpunge (b); + expunge_block_nocompact (b); + changed = true; + } + else + { + BASIC_BLOCK (j) = b; + b->index = j++; + } } + n_basic_blocks = j; + basic_block_info->num_elements = j; if (changed) tidy_fallthru_edges (); |