diff options
| author | rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2007-10-12 08:42:13 +0000 |
|---|---|---|
| committer | rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2007-10-12 08:42:13 +0000 |
| commit | 484b827b2ef32bd7c3e1b075e1e4344ba3aa402a (patch) | |
| tree | f8336d7e5dd6093801511dfd43a58da560108cd7 /gcc/tree-ssa-forwprop.c | |
| parent | f1f6fb1dd24936083f1d5c2829b506222a9396a3 (diff) | |
| download | gcc-484b827b2ef32bd7c3e1b075e1e4344ba3aa402a.tar.gz | |
2007-10-12 Richard Guenther <rguenther@suse.de>
PR middle-end/26198
* tree-ssa-forwprop.c (can_propagate_from): Do not propagate from
a rhs with side-effects or which is a load.
(forward_propagate_into_cond): Also try combining both operands.
* gcc.dg/tree-ssa/forwprop-3.c: New testcase.
* gcc.c-torture/execute/20071011-1.c: Likewise.
* gcc.dg/tree-ssa/ssa-pre-9.c: Adjust.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@129256 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/tree-ssa-forwprop.c')
| -rw-r--r-- | gcc/tree-ssa-forwprop.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c index 3b72b6c44af..b92a9f13f48 100644 --- a/gcc/tree-ssa-forwprop.c +++ b/gcc/tree-ssa-forwprop.c @@ -237,6 +237,14 @@ can_propagate_from (tree def_stmt) { tree rhs = GIMPLE_STMT_OPERAND (def_stmt, 1); + /* If the rhs has side-effects we cannot propagate from it. */ + if (TREE_SIDE_EFFECTS (rhs)) + return false; + + /* If the rhs is a load we cannot propagate from it. */ + if (REFERENCE_CLASS_P (rhs)) + return false; + /* We cannot propagate ssa names that occur in abnormal phi nodes. */ switch (TREE_CODE_LENGTH (TREE_CODE (rhs))) { @@ -351,7 +359,7 @@ forward_propagate_into_cond (tree cond_expr, tree stmt) do { tree tmp = NULL_TREE; tree cond = COND_EXPR_COND (cond_expr); - tree name, def_stmt, rhs; + tree name, def_stmt, rhs0 = NULL_TREE, rhs1 = NULL_TREE; bool single_use_p; /* We can do tree combining on SSA_NAME and comparison expressions. */ @@ -366,9 +374,9 @@ forward_propagate_into_cond (tree cond_expr, tree stmt) && can_propagate_from (def_stmt)) { tree op1 = TREE_OPERAND (cond, 1); - rhs = GIMPLE_STMT_OPERAND (def_stmt, 1); + rhs0 = GIMPLE_STMT_OPERAND (def_stmt, 1); tmp = combine_cond_expr_cond (TREE_CODE (cond), boolean_type_node, - fold_convert (TREE_TYPE (op1), rhs), + fold_convert (TREE_TYPE (op1), rhs0), op1, !single_use_p); } /* If that wasn't successful, try the second operand. */ @@ -382,12 +390,20 @@ forward_propagate_into_cond (tree cond_expr, tree stmt) || !can_propagate_from (def_stmt)) return did_something; - rhs = GIMPLE_STMT_OPERAND (def_stmt, 1); + rhs1 = GIMPLE_STMT_OPERAND (def_stmt, 1); tmp = combine_cond_expr_cond (TREE_CODE (cond), boolean_type_node, op0, - fold_convert (TREE_TYPE (op0), rhs), + fold_convert (TREE_TYPE (op0), rhs1), !single_use_p); } + /* If that wasn't successful either, try both operands. */ + if (tmp == NULL_TREE + && rhs0 != NULL_TREE + && rhs1 != NULL_TREE) + tmp = combine_cond_expr_cond (TREE_CODE (cond), boolean_type_node, + rhs0, + fold_convert (TREE_TYPE (rhs0), rhs1), + !single_use_p); } else if (TREE_CODE (cond) == SSA_NAME) { @@ -397,9 +413,9 @@ forward_propagate_into_cond (tree cond_expr, tree stmt) || !can_propagate_from (def_stmt)) return did_something; - rhs = GIMPLE_STMT_OPERAND (def_stmt, 1); - tmp = combine_cond_expr_cond (NE_EXPR, boolean_type_node, rhs, - build_int_cst (TREE_TYPE (rhs), 0), + rhs0 = GIMPLE_STMT_OPERAND (def_stmt, 1); + tmp = combine_cond_expr_cond (NE_EXPR, boolean_type_node, rhs0, + build_int_cst (TREE_TYPE (rhs0), 0), false); } |