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| author | Richard Guenther <rguenther@suse.de> | 2006-05-16 15:34:12 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2006-05-16 15:34:12 +0000 |
| commit | faaf14368b72d741b4ea5bcb6b8cb172fb847c43 (patch) | |
| tree | edbdd4f49cf5e328f497b63f183f1354221dafa4 /gcc/tree-ssa-ccp.c | |
| parent | 14c7833ccd0392c40505c4f707abc7ef64af7972 (diff) | |
| download | gcc-faaf14368b72d741b4ea5bcb6b8cb172fb847c43.zip gcc-faaf14368b72d741b4ea5bcb6b8cb172fb847c43.tar.gz gcc-faaf14368b72d741b4ea5bcb6b8cb172fb847c43.tar.bz2 | |
re PR tree-optimization/22303 (CCP does not handle STRING_CSTs)
2006-05-16 Richard Guenther <rguenther@suse.de>
PR tree-optimization/22303
* tree-ssa-ccp.c (fold_const_aggregate_ref): Handle reads
from STRING_CSTs.
(evaluate_stmt): Fall back to fold_const_aggregate_ref, if
ccp_fold did not simplify the statement.
* gcc.dg/tree-ssa/ssa-ccp-13.c: New testcase.
From-SVN: r113826
Diffstat (limited to 'gcc/tree-ssa-ccp.c')
| -rw-r--r-- | gcc/tree-ssa-ccp.c | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c index 83dce72..53050e6 100644 --- a/gcc/tree-ssa-ccp.c +++ b/gcc/tree-ssa-ccp.c @@ -1011,7 +1011,8 @@ fold_const_aggregate_ref (tree t) } if (ctor == NULL_TREE - || TREE_CODE (ctor) != CONSTRUCTOR + || (TREE_CODE (ctor) != CONSTRUCTOR + && TREE_CODE (ctor) != STRING_CST) || !TREE_STATIC (ctor)) return NULL_TREE; @@ -1036,6 +1037,20 @@ fold_const_aggregate_ref (tree t) return NULL_TREE; } + /* Fold read from constant string. */ + if (TREE_CODE (ctor) == STRING_CST) + { + if ((TYPE_MODE (TREE_TYPE (t)) + == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) + && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) + == MODE_INT) + && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1 + && compare_tree_int (idx, TREE_STRING_LENGTH (ctor)) < 0) + return build_int_cst (TREE_TYPE (t), (TREE_STRING_POINTER (ctor) + [TREE_INT_CST_LOW (idx)])); + return NULL_TREE; + } + /* Whoo-hoo! I'll fold ya baby. Yeah! */ FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) if (tree_int_cst_equal (cfield, idx)) @@ -1104,7 +1119,7 @@ static prop_value_t evaluate_stmt (tree stmt) { prop_value_t val; - tree simplified; + tree simplified = NULL_TREE; ccp_lattice_t likelyvalue = likely_value (stmt); val.mem_ref = NULL_TREE; @@ -1115,14 +1130,14 @@ evaluate_stmt (tree stmt) simplified = ccp_fold (stmt); /* If the statement is likely to have a VARYING result, then do not bother folding the statement. */ - else if (likelyvalue == VARYING) + if (likelyvalue == VARYING) simplified = get_rhs (stmt); /* If the statement is an ARRAY_REF or COMPONENT_REF into constant aggregates, extract the referenced constant. Otherwise the statement is likely to have an UNDEFINED value, and there will be nothing to do. Note that fold_const_aggregate_ref returns NULL_TREE if the first case does not match. */ - else + else if (!simplified) simplified = fold_const_aggregate_ref (get_rhs (stmt)); if (simplified && is_gimple_min_invariant (simplified)) |