static unsigned int tree_ssa_phiopt_worker (bool, bool);
static bool conditional_replacement (basic_block, basic_block,
edge, edge, gphi *, tree, tree);
+static bool factor_out_conditional_conversion (edge, edge, gphi *, tree, tree);
static int value_replacement (basic_block, basic_block,
edge, edge, gimple, tree, tree);
static bool minmax_replacement (basic_block, basic_block,
node. */
gcc_assert (arg0 != NULL && arg1 != NULL);
+ if (factor_out_conditional_conversion (e1, e2, phi, arg0, arg1))
+ {
+ /* factor_out_conditional_conversion may create a new PHI in
+ BB2 and eliminate an existing PHI in BB2. Recompute values
+ that may be affected by that change. */
+ phis = phi_nodes (bb2);
+ phi = single_non_singleton_phi_for_edges (phis, e1, e2);
+ gcc_assert (phi);
+ arg0 = gimple_phi_arg_def (phi, e1->dest_idx);
+ arg1 = gimple_phi_arg_def (phi, e2->dest_idx);
+ gcc_assert (arg0 != NULL && arg1 != NULL);
+ }
+
/* Do the replacement of conditional if it can be done. */
if (conditional_replacement (bb, bb1, e1, e2, phi, arg0, arg1))
cfgchanged = true;
bb->index);
}
+/* PR66726: Factor conversion out of COND_EXPR. If the arguments of the PHI
+ stmt are CONVERT_STMT, factor out the conversion and perform the conversion
+ to the result of PHI stmt. */
+
+static bool
+factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
+ tree arg0, tree arg1)
+{
+ gimple arg0_def_stmt = NULL, arg1_def_stmt = NULL, new_stmt;
+ tree new_arg0 = NULL_TREE, new_arg1 = NULL_TREE;
+ tree temp, result;
+ gphi *newphi;
+ gimple_stmt_iterator gsi, gsi_for_def;
+ source_location locus = gimple_location (phi);
+ enum tree_code convert_code;
+
+ /* Handle only PHI statements with two arguments. TODO: If all
+ other arguments to PHI are INTEGER_CST or if their defining
+ statement have the same unary operation, we can handle more
+ than two arguments too. */
+ if (gimple_phi_num_args (phi) != 2)
+ return false;
+
+ /* First canonicalize to simplify tests. */
+ if (TREE_CODE (arg0) != SSA_NAME)
+ {
+ std::swap (arg0, arg1);
+ std::swap (e0, e1);
+ }
+
+ if (TREE_CODE (arg0) != SSA_NAME
+ || (TREE_CODE (arg1) != SSA_NAME
+ && TREE_CODE (arg1) != INTEGER_CST))
+ return false;
+
+ /* Check if arg0 is an SSA_NAME and the stmt which defines arg0 is
+ a conversion. */
+ arg0_def_stmt = SSA_NAME_DEF_STMT (arg0);
+ if (!is_gimple_assign (arg0_def_stmt)
+ || !gimple_assign_cast_p (arg0_def_stmt))
+ return false;
+
+ /* Use the RHS as new_arg0. */
+ convert_code = gimple_assign_rhs_code (arg0_def_stmt);
+ new_arg0 = gimple_assign_rhs1 (arg0_def_stmt);
+ if (convert_code == VIEW_CONVERT_EXPR)
+ new_arg0 = TREE_OPERAND (new_arg0, 0);
+
+ if (TREE_CODE (arg1) == SSA_NAME)
+ {
+ /* Check if arg1 is an SSA_NAME and the stmt which defines arg1
+ is a conversion. */
+ arg1_def_stmt = SSA_NAME_DEF_STMT (arg1);
+ if (!is_gimple_assign (arg1_def_stmt)
+ || gimple_assign_rhs_code (arg1_def_stmt) != convert_code)
+ return false;
+
+ /* Use the RHS as new_arg1. */
+ new_arg1 = gimple_assign_rhs1 (arg1_def_stmt);
+ if (convert_code == VIEW_CONVERT_EXPR)
+ new_arg1 = TREE_OPERAND (new_arg1, 0);
+ }
+ else
+ {
+ /* If arg1 is an INTEGER_CST, fold it to new type. */
+ if (INTEGRAL_TYPE_P (TREE_TYPE (new_arg0))
+ && int_fits_type_p (arg1, TREE_TYPE (new_arg0)))
+ {
+ if (gimple_assign_cast_p (arg0_def_stmt))
+ new_arg1 = fold_convert (TREE_TYPE (new_arg0), arg1);
+ else
+ return false;
+ }
+ else
+ return false;
+ }
+
+ /* If arg0/arg1 have > 1 use, then this transformation actually increases
+ the number of expressions evaluated at runtime. */
+ if (!has_single_use (arg0)
+ || (arg1_def_stmt && !has_single_use (arg1)))
+ return false;
+
+ /* If types of new_arg0 and new_arg1 are different bailout. */
+ if (!types_compatible_p (TREE_TYPE (new_arg0), TREE_TYPE (new_arg1)))
+ return false;
+
+ /* Create a new PHI stmt. */
+ result = PHI_RESULT (phi);
+ temp = make_ssa_name (TREE_TYPE (new_arg0), NULL);
+ newphi = create_phi_node (temp, gimple_bb (phi));
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "PHI ");
+ print_generic_expr (dump_file, gimple_phi_result (phi), 0);
+ fprintf (dump_file,
+ " changed to factor conversion out from COND_EXPR.\n");
+ fprintf (dump_file, "New stmt with CAST that defines ");
+ print_generic_expr (dump_file, result, 0);
+ fprintf (dump_file, ".\n");
+ }
+
+ /* Remove the old cast(s) that has single use. */
+ gsi_for_def = gsi_for_stmt (arg0_def_stmt);
+ gsi_remove (&gsi_for_def, true);
+ if (arg1_def_stmt)
+ {
+ gsi_for_def = gsi_for_stmt (arg1_def_stmt);
+ gsi_remove (&gsi_for_def, true);
+ }
+
+ add_phi_arg (newphi, new_arg0, e0, locus);
+ add_phi_arg (newphi, new_arg1, e1, locus);
+
+ /* Create the conversion stmt and insert it. */
+ if (convert_code == VIEW_CONVERT_EXPR)
+ temp = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (result), temp);
+ new_stmt = gimple_build_assign (result, convert_code, temp);
+ gsi = gsi_after_labels (gimple_bb (phi));
+ gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT);
+
+ /* Remove he original PHI stmt. */
+ gsi = gsi_for_stmt (phi);
+ gsi_remove (&gsi, true);
+ return true;
+}
+
/* The function conditional_replacement does the main work of doing the
conditional replacement. Return true if the replacement is done.
Otherwise return false.
This pass also performs a fifth transformation of a slightly different
flavor.
+ Factor conversion in COND_EXPR
+ ------------------------------
+
+ This transformation factors the conversion out of COND_EXPR with
+ factor_out_conditional_conversion.
+
+ For example:
+ if (a <= CST) goto <bb 3>; else goto <bb 4>;
+ <bb 3>:
+ tmp = (int) a;
+ <bb 4>:
+ tmp = PHI <tmp, CST>
+
+ Into:
+ if (a <= CST) goto <bb 3>; else goto <bb 4>;
+ <bb 3>:
+ <bb 4>:
+ a = PHI <a, CST>
+ tmp = (int) a;
+
Adjacent Load Hoisting
----------------------
projects / gcc.git / commitdiff