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-rw-r--r--gcc/tree-ssa-forwprop.c53
1 files changed, 20 insertions, 33 deletions
diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index fb079dd0e24..02b41b6e6c8 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.
@@ -323,27 +313,32 @@ 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;
+ 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
@@ -351,7 +346,7 @@ 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;
@@ -360,7 +355,8 @@ 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)
@@ -368,7 +364,7 @@ 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
@@ -456,7 +452,7 @@ 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);
}
@@ -466,7 +462,7 @@ substitute_single_use_vars (varray_type *cond_worklist,
whatever block it might be in. */
if (num_uses && num_uses == propagated_uses)
{
- block_stmt_iterator bsi = bsi_for_stmt (def);
+ block_stmt_iterator bsi = bsi_for_stmt (def_stmt);
bsi_remove (&bsi);
}
}
@@ -502,9 +498,6 @@ 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);
@@ -512,12 +505,6 @@ 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 ();
}
}