diff options
Diffstat (limited to 'gcc/tree-ssa-forwprop.c')
| -rw-r--r-- | gcc/tree-ssa-forwprop.c | 55 |
1 files changed, 21 insertions, 34 deletions
diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c index cbf1fdec578..4ac8a9fba28 100644 --- a/gcc/tree-ssa-forwprop.c +++ b/gcc/tree-ssa-forwprop.c @@ -113,22 +113,12 @@ Boston, MA 02111-1307, USA. */ by record_single_argument_cond_exprs and tested in need_imm_uses_for. */ static bitmap vars; -static bool need_imm_uses_for (tree); static void tree_ssa_forward_propagate_single_use_vars (void); static void record_single_argument_cond_exprs (varray_type, varray_type *, bitmap); static void substitute_single_use_vars (varray_type *, varray_type); -/* Function indicating whether we ought to include information for 'var' - when calculating immediate uses. */ - -static bool -need_imm_uses_for (tree var) -{ - return bitmap_bit_p (vars, SSA_NAME_VERSION (var)); -} - /* Find all COND_EXPRs with a condition that is a naked SSA_NAME or an equality comparison against a constant. @@ -323,28 +313,33 @@ static void substitute_single_use_vars (varray_type *cond_worklist, varray_type vars_worklist) { + use_operand_p use_p; while (VARRAY_ACTIVE_SIZE (vars_worklist) > 0) { tree test_var = VARRAY_TOP_TREE (vars_worklist); - tree def = SSA_NAME_DEF_STMT (test_var); - dataflow_t df; - int j, num_uses, propagated_uses; + tree def_stmt = SSA_NAME_DEF_STMT (test_var); + tree def; + int num_uses, propagated_uses; block_stmt_iterator bsi; + imm_use_iterator imm_iter; VARRAY_POP (vars_worklist); - /* Now compute the immediate uses of TEST_VAR. */ - df = get_immediate_uses (def); - num_uses = num_immediate_uses (df); propagated_uses = 0; + num_uses = 0; + if (NUM_DEFS (STMT_DEF_OPS (def_stmt)) != 1) + continue; + + def = DEF_OP (STMT_DEF_OPS (def_stmt), 0); /* If TEST_VAR is used more than once and is not a boolean set via TRUTH_NOT_EXPR with another SSA_NAME as its argument, then we can not optimize. */ - if (num_uses == 1 + + if (has_single_use (def) || (TREE_CODE (TREE_TYPE (test_var)) == BOOLEAN_TYPE - && TREE_CODE (TREE_OPERAND (def, 1)) == TRUTH_NOT_EXPR - && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (def, 1), 0)) + && TREE_CODE (TREE_OPERAND (def_stmt, 1)) == TRUTH_NOT_EXPR + && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (def_stmt, 1), 0)) == SSA_NAME))) ; else @@ -352,7 +347,7 @@ substitute_single_use_vars (varray_type *cond_worklist, /* Walk over each use and try to forward propagate the RHS of DEF into the use. */ - for (j = 0; j < num_uses; j++) + FOR_EACH_IMM_USE_SAFE (use_p, imm_iter, def) { tree cond_stmt; tree cond; @@ -361,7 +356,8 @@ substitute_single_use_vars (varray_type *cond_worklist, enum tree_code def_rhs_code; tree new_cond; - cond_stmt = immediate_use (df, j); + cond_stmt = USE_STMT (use_p); + num_uses++; /* For now we can only propagate into COND_EXPRs. */ if (TREE_CODE (cond_stmt) != COND_EXPR) @@ -369,7 +365,7 @@ substitute_single_use_vars (varray_type *cond_worklist, cond = COND_EXPR_COND (cond_stmt); cond_code = TREE_CODE (cond); - def_rhs = TREE_OPERAND (def, 1); + def_rhs = TREE_OPERAND (def_stmt, 1); def_rhs_code = TREE_CODE (def_rhs); /* If the definition of the single use variable was from an @@ -457,7 +453,7 @@ substitute_single_use_vars (varray_type *cond_worklist, /* Replace the condition. */ COND_EXPR_COND (cond_stmt) = new_cond; - modify_stmt (cond_stmt); + update_stmt (cond_stmt); propagated_uses++; VARRAY_PUSH_TREE (*cond_worklist, cond_stmt); } @@ -466,11 +462,11 @@ substitute_single_use_vars (varray_type *cond_worklist, Unfortunately, we have to find the defining statement in whatever block it might be in. */ if (num_uses && num_uses == propagated_uses) - for (bsi = bsi_start (bb_for_stmt (def)); + for (bsi = bsi_start (bb_for_stmt (def_stmt)); !bsi_end_p (bsi); bsi_next (&bsi)) { - if (def == bsi_stmt (bsi)) + if (def_stmt == bsi_stmt (bsi)) { bsi_remove (&bsi); break; @@ -509,9 +505,6 @@ tree_ssa_forward_propagate_single_use_vars (void) if (VARRAY_ACTIVE_SIZE (vars_worklist) > 0) { - /* Now compute immediate uses for all the variables we care about. */ - compute_immediate_uses (TDFA_USE_OPS, need_imm_uses_for); - /* We've computed immediate uses, so we can/must clear the VARS bitmap for the next iteration. */ bitmap_clear (vars); @@ -519,12 +512,6 @@ tree_ssa_forward_propagate_single_use_vars (void) /* And optimize. This will drain VARS_WORKLIST and initialize COND_WORKLIST for the next iteration. */ substitute_single_use_vars (&cond_worklist, vars_worklist); - - /* We do not incrementally update the dataflow information - so we must free it here and recompute the necessary bits - on the next iteration. If this turns out to be expensive, - methods for incrementally updating the dataflow are known. */ - free_df (); } } |