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| author | Jakub Jelinek <jakub@redhat.com> | 2007-10-29 23:26:59 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2007-10-29 23:26:59 +0100 |
| commit | 489f2598af821da1157ec21cd484fcb32a5193e9 (patch) | |
| tree | 2b6f28406d370623a5e985861bc9536a99083bfa /gcc/c-gimplify.c | |
| parent | 9f1da821e6de1d5068d8c03cd46d1b05aab799f1 (diff) | |
| download | gcc-489f2598af821da1157ec21cd484fcb32a5193e9.tar.gz | |
re PR tree-optimization/33723 (Inefficient code with compound literals)
PR tree-optimization/33723
* c-gimplify.c (c_gimplify_expr): Optimize INIT_EXPR or
MODIFY_EXPR with non-addressable COMPOUND_LITERAL_EXPR as source.
* gcc.c-torture/execute/20071029-1.c: New test.
* gcc.dg/tree-ssa/pr33723.c: New test.
From-SVN: r129743
Diffstat (limited to 'gcc/c-gimplify.c')
| -rw-r--r-- | gcc/c-gimplify.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/gcc/c-gimplify.c b/gcc/c-gimplify.c index 9721b67008b..a1ee27bfb70 100644 --- a/gcc/c-gimplify.c +++ b/gcc/c-gimplify.c @@ -233,6 +233,29 @@ c_gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p ATTRIBUTE_UNUSED) case COMPOUND_LITERAL_EXPR: return gimplify_compound_literal_expr (expr_p, pre_p); + case INIT_EXPR: + case MODIFY_EXPR: + if (TREE_CODE (TREE_OPERAND (*expr_p, 1)) == COMPOUND_LITERAL_EXPR) + { + tree complit = TREE_OPERAND (*expr_p, 1); + tree decl_s = COMPOUND_LITERAL_EXPR_DECL_STMT (complit); + tree decl = DECL_EXPR_DECL (decl_s); + tree init = DECL_INITIAL (decl); + + /* struct T x = (struct T) { 0, 1, 2 } can be optimized + into struct T x = { 0, 1, 2 } if the address of the + compound literal has never been taken. */ + if (!TREE_ADDRESSABLE (complit) + && !TREE_ADDRESSABLE (decl) + && init) + { + *expr_p = copy_node (*expr_p); + TREE_OPERAND (*expr_p, 1) = init; + return GS_OK; + } + } + return GS_UNHANDLED; + default: return GS_UNHANDLED; } |