diff options
| author | Richard Guenther <rguenther@suse.de> | 2008-08-21 15:18:58 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2008-08-21 15:18:58 +0000 |
| commit | 1e52075c544a9808b4b370ef974c198f3bb639b5 (patch) | |
| tree | d081e2983bcdcea812e826d40060ea64e94eb58a /gcc/tree-ssa-pre.c | |
| parent | 729edaa1bb60f7bffea3ed7e701373d6f37af8b0 (diff) | |
| download | gcc-1e52075c544a9808b4b370ef974c198f3bb639b5.zip gcc-1e52075c544a9808b4b370ef974c198f3bb639b5.tar.gz gcc-1e52075c544a9808b4b370ef974c198f3bb639b5.tar.bz2 | |
tree-ssa-pre.c (insert_into_preds_of_block): Before inserting a PHI ask VN if it is already available.
2008-08-21 Richard Guenther <rguenther@suse.de>
* tree-ssa-pre.c (insert_into_preds_of_block): Before inserting
a PHI ask VN if it is already available.
* tree-ssa-sccvn.h (vn_phi_lookup): Declare.
* tree-ssa-sccvn.c (vn_phi_lookup): Export.
From-SVN: r139388
Diffstat (limited to 'gcc/tree-ssa-pre.c')
| -rw-r--r-- | gcc/tree-ssa-pre.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c index d2a55ae..606cafa 100644 --- a/gcc/tree-ssa-pre.c +++ b/gcc/tree-ssa-pre.c @@ -2896,7 +2896,7 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum, pre_expr eprime; edge_iterator ei; tree type = get_expr_type (expr); - tree temp; + tree temp, res; gimple phi; if (dump_file && (dump_flags & TDF_DETAILS)) @@ -3051,12 +3051,8 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum, if (TREE_CODE (type) == COMPLEX_TYPE || TREE_CODE (type) == VECTOR_TYPE) DECL_GIMPLE_REG_P (temp) = 1; - phi = create_phi_node (temp, block); - gimple_set_plf (phi, NECESSARY, false); - VN_INFO_GET (gimple_phi_result (phi))->valnum = gimple_phi_result (phi); - VN_INFO (gimple_phi_result (phi))->value_id = val; - VEC_safe_push (gimple, heap, inserted_exprs, phi); + phi = create_phi_node (temp, block); FOR_EACH_EDGE (pred, ei, block->preds) { pre_expr ae = avail[pred->src->index]; @@ -3067,6 +3063,20 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum, else add_phi_arg (phi, PRE_EXPR_NAME (avail[pred->src->index]), pred); } + /* If the PHI node is already available, use it. */ + if ((res = vn_phi_lookup (phi)) != NULL_TREE) + { + gimple_stmt_iterator gsi = gsi_for_stmt (phi); + remove_phi_node (&gsi, true); + release_defs (phi); + add_to_value (val, get_or_alloc_expr_for_name (res)); + return false; + } + + gimple_set_plf (phi, NECESSARY, false); + VN_INFO_GET (gimple_phi_result (phi))->valnum = gimple_phi_result (phi); + VN_INFO (gimple_phi_result (phi))->value_id = val; + VEC_safe_push (gimple, heap, inserted_exprs, phi); newphi = get_or_alloc_expr_for_name (gimple_phi_result (phi)); add_to_value (val, newphi); |