diff options
Diffstat (limited to 'gcc/tree-ssanames.c')
| -rw-r--r-- | gcc/tree-ssanames.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/gcc/tree-ssanames.c b/gcc/tree-ssanames.c index bb0880260ff..46fa42029ce 100644 --- a/gcc/tree-ssanames.c +++ b/gcc/tree-ssanames.c @@ -3,17 +3,17 @@ Free Software Foundation, Inc. This file is part of GCC. - + GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. - + GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. - + You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see <http://www.gnu.org/licenses/>. */ @@ -30,7 +30,7 @@ along with GCC; see the file COPYING3. If not see /* Rewriting a function into SSA form can create a huge number of SSA_NAMEs, many of which may be thrown away shortly after their creation if jumps - were threaded through PHI nodes. + were threaded through PHI nodes. While our garbage collection mechanisms will handle this situation, it is extremely wasteful to create nodes and throw them away, especially @@ -44,7 +44,7 @@ along with GCC; see the file COPYING3. If not see Right now we maintain our free list on a per-function basis. It may or may not make sense to maintain the free list for the duration of - a compilation unit. + a compilation unit. External code should rely solely upon HIGHEST_SSA_VERSION and the externally defined functions. External code should not know about @@ -166,7 +166,7 @@ make_ssa_name_fn (struct function *fn, tree var, gimple stmt) /* We no longer need the SSA_NAME expression VAR, release it so that - it may be reused. + it may be reused. Note it is assumed that no calls to make_ssa_name will be made until all uses of the ssa name are released and that the only @@ -195,7 +195,7 @@ release_ssa_name (tree var) /* release_ssa_name can be called multiple times on a single SSA_NAME. However, it should only end up on our free list one time. We keep a status bit in the SSA_NAME node itself to indicate it has - been put on the free list. + been put on the free list. Note that once on the freelist you can not reference the SSA_NAME's defining statement. */ |