diff options
Diffstat (limited to 'gcc/tree-ssa-forwprop.c')
| -rw-r--r-- | gcc/tree-ssa-forwprop.c | 65 |
1 files changed, 35 insertions, 30 deletions
diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c index 577609b..5d04fc3 100644 --- a/gcc/tree-ssa-forwprop.c +++ b/gcc/tree-ssa-forwprop.c @@ -313,8 +313,10 @@ remove_prop_source_from_use (tree name) return cfg_changed; stmt = SSA_NAME_DEF_STMT (name); - gsi = gsi_for_stmt (stmt); bb = gimple_bb (stmt); + if (!bb) + return cfg_changed; + gsi = gsi_for_stmt (stmt); release_defs (stmt); gsi_remove (&gsi, true); cfg_changed |= gimple_purge_dead_eh_edges (bb); @@ -437,29 +439,36 @@ forward_propagate_into_comparison_1 (location_t loc, /* Propagate from the ssa name definition statements of the assignment from a comparison at *GSI into the conditional if that simplifies it. - Returns true if the stmt was modified, false if not. */ + Returns 1 if the stmt was modified and 2 if the CFG needs cleanup, + otherwise returns 0. */ -static bool +static int forward_propagate_into_comparison (gimple_stmt_iterator *gsi) { gimple stmt = gsi_stmt (*gsi); tree tmp; + bool cfg_changed = false; + tree rhs1 = gimple_assign_rhs1 (stmt); + tree rhs2 = gimple_assign_rhs2 (stmt); /* Combine the comparison with defining statements. */ tmp = forward_propagate_into_comparison_1 (gimple_location (stmt), gimple_assign_rhs_code (stmt), TREE_TYPE (gimple_assign_lhs (stmt)), - gimple_assign_rhs1 (stmt), - gimple_assign_rhs2 (stmt)); + rhs1, rhs2); if (tmp) { gimple_assign_set_rhs_from_tree (gsi, tmp); update_stmt (stmt); - return true; + if (TREE_CODE (rhs1) == SSA_NAME) + cfg_changed |= remove_prop_source_from_use (rhs1); + if (TREE_CODE (rhs2) == SSA_NAME) + cfg_changed |= remove_prop_source_from_use (rhs2); + return cfg_changed ? 2 : 1; } - return false; + return 0; } /* Propagate from the ssa name definition statements of COND_EXPR @@ -472,10 +481,12 @@ forward_propagate_into_comparison (gimple_stmt_iterator *gsi) static int forward_propagate_into_gimple_cond (gimple stmt) { - int did_something = 0; location_t loc = gimple_location (stmt); tree tmp; enum tree_code code = gimple_cond_code (stmt); + bool cfg_changed = false; + tree rhs1 = gimple_cond_lhs (stmt); + tree rhs2 = gimple_cond_rhs (stmt); /* We can do tree combining on SSA_NAME and comparison expressions. */ if (TREE_CODE_CLASS (gimple_cond_code (stmt)) != tcc_comparison) @@ -483,18 +494,13 @@ forward_propagate_into_gimple_cond (gimple stmt) tmp = forward_propagate_into_comparison_1 (loc, code, boolean_type_node, - gimple_cond_lhs (stmt), - gimple_cond_rhs (stmt)); + rhs1, rhs2); if (tmp) { if (dump_file && tmp) { - tree cond = build2 (gimple_cond_code (stmt), - boolean_type_node, - gimple_cond_lhs (stmt), - gimple_cond_rhs (stmt)); fprintf (dump_file, " Replaced '"); - print_generic_expr (dump_file, cond, 0); + print_gimple_expr (dump_file, stmt, 0, 0); fprintf (dump_file, "' with '"); print_generic_expr (dump_file, tmp, 0); fprintf (dump_file, "'\n"); @@ -503,14 +509,14 @@ forward_propagate_into_gimple_cond (gimple stmt) gimple_cond_set_condition_from_tree (stmt, unshare_expr (tmp)); update_stmt (stmt); - /* Remove defining statements. */ - if (is_gimple_min_invariant (tmp)) - did_something = 2; - else if (did_something == 0) - did_something = 1; + if (TREE_CODE (rhs1) == SSA_NAME) + cfg_changed |= remove_prop_source_from_use (rhs1); + if (TREE_CODE (rhs2) == SSA_NAME) + cfg_changed |= remove_prop_source_from_use (rhs2); + return (cfg_changed || is_gimple_min_invariant (tmp)) ? 2 : 1; } - return did_something; + return 0; } @@ -526,7 +532,6 @@ forward_propagate_into_cond (gimple_stmt_iterator *gsi_p) { gimple stmt = gsi_stmt (*gsi_p); location_t loc = gimple_location (stmt); - int did_something = 0; tree tmp = NULL_TREE; tree cond = gimple_assign_rhs1 (stmt); @@ -541,7 +546,7 @@ forward_propagate_into_cond (gimple_stmt_iterator *gsi_p) tree name = cond, rhs0; gimple def_stmt = get_prop_source_stmt (name, true, NULL); if (!def_stmt || !can_propagate_from (def_stmt)) - return did_something; + return 0; rhs0 = gimple_assign_rhs1 (def_stmt); tmp = combine_cond_expr_cond (loc, NE_EXPR, boolean_type_node, rhs0, @@ -564,14 +569,10 @@ forward_propagate_into_cond (gimple_stmt_iterator *gsi_p) stmt = gsi_stmt (*gsi_p); update_stmt (stmt); - /* Remove defining statements. */ - if (is_gimple_min_invariant (tmp)) - did_something = 2; - else if (did_something == 0) - did_something = 1; + return is_gimple_min_invariant (tmp) ? 2 : 1; } - return did_something; + return 0; } /* We've just substituted an ADDR_EXPR into stmt. Update all the @@ -2441,11 +2442,15 @@ ssa_forward_propagate_and_combine (void) else if (TREE_CODE_CLASS (code) == tcc_comparison) { bool no_warning = gimple_no_warning_p (stmt); + int did_something; fold_defer_overflow_warnings (); - changed = forward_propagate_into_comparison (&gsi); + did_something = forward_propagate_into_comparison (&gsi); + if (did_something == 2) + cfg_changed = true; fold_undefer_overflow_warnings (!no_warning && changed, stmt, WARN_STRICT_OVERFLOW_CONDITIONAL); + changed = did_something != 0; } else if (code == BIT_AND_EXPR || code == BIT_IOR_EXPR |