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| author | Steven Bosscher <stevenb@suse.de> | 2005-02-10 22:57:30 +0000 |
|---|---|---|
| committer | Steven Bosscher <steven@gcc.gnu.org> | 2005-02-10 22:57:30 +0000 |
| commit | 3b6616ddc44fe5f8e10457a1bc830e01d38ca5d7 (patch) | |
| tree | 8a75234439f297ec9f0bab12690742aba6a15db7 /gcc | |
| parent | a0c5992a2084f23d36187430a733673e2601705e (diff) | |
| download | gcc-3b6616ddc44fe5f8e10457a1bc830e01d38ca5d7.zip gcc-3b6616ddc44fe5f8e10457a1bc830e01d38ca5d7.tar.gz gcc-3b6616ddc44fe5f8e10457a1bc830e01d38ca5d7.tar.bz2 | |
re PR tree-optimization/17549 (10% increase in codesize with C code compared to GCC 3.3)
PR tree-optimization/17549
* tree-outof-ssa.c (find_replaceable_in_bb): Do not allow
TER to replace a DEF with its expression if the DEF and the
rhs of the expression we replace into have the same root
variable.
From-SVN: r94853
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/tree-outof-ssa.c | 19 |
2 files changed, 25 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 3ea3e79..d86daf4 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2005-02-10 Steven Bosscher <stevenb@suse.de> + + PR tree-optimization/17549 + * tree-outof-ssa.c (find_replaceable_in_bb): Do not allow + TER to replace a DEF with its expression if the DEF and the + rhs of the expression we replace into have the same root + variable. + 2005-02-10 Richard Sandiford <rsandifo@redhat.com> * config/mips/mips.md: Fix the placement of the match_scratch in the diff --git a/gcc/tree-outof-ssa.c b/gcc/tree-outof-ssa.c index 65c74d3..c6aa812 100644 --- a/gcc/tree-outof-ssa.c +++ b/gcc/tree-outof-ssa.c @@ -1659,8 +1659,23 @@ find_replaceable_in_bb (temp_expr_table_p tab, basic_block bb) { if (tab->version_info[SSA_NAME_VERSION (def)]) { - /* Mark expression as replaceable unless stmt is volatile. */ - if (!ann->has_volatile_ops) + bool same_root_var = false; + tree def2; + ssa_op_iter iter2; + + /* See if the root variables are the same. If they are, we + do not want to do the replacement to avoid problems with + code size, see PR tree-optimization/17549. */ + FOR_EACH_SSA_TREE_OPERAND (def2, stmt, iter2, SSA_OP_DEF) + if (SSA_NAME_VAR (def) == SSA_NAME_VAR (def2)) + { + same_root_var = true; + break; + } + + /* Mark expression as replaceable unless stmt is volatile + or DEF sets the same root variable as STMT. */ + if (!ann->has_volatile_ops && !same_root_var) mark_replaceable (tab, def); else finish_expr (tab, SSA_NAME_VERSION (def), false); |