diff options
Diffstat (limited to 'gcc/tree-ssa-phiopt.c')
| -rw-r--r-- | gcc/tree-ssa-phiopt.c | 63 |
1 files changed, 53 insertions, 10 deletions
diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c index 5f283890..b97f863 100644 --- a/gcc/tree-ssa-phiopt.c +++ b/gcc/tree-ssa-phiopt.c @@ -1363,22 +1363,21 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb, edge e0, edge e1, gimple *phi, tree arg0, tree arg1) { - tree result, type, rhs; - gcond *cond; + tree result; edge true_edge, false_edge; - enum tree_code cmp, minmax, ass_code; - tree smaller, alt_smaller, larger, alt_larger, arg_true, arg_false; + enum tree_code minmax, ass_code; + tree smaller, larger, arg_true, arg_false; gimple_stmt_iterator gsi, gsi_from; - type = TREE_TYPE (PHI_RESULT (phi)); + tree type = TREE_TYPE (PHI_RESULT (phi)); /* The optimization may be unsafe due to NaNs. */ if (HONOR_NANS (type) || HONOR_SIGNED_ZEROS (type)) return false; - cond = as_a <gcond *> (last_stmt (cond_bb)); - cmp = gimple_cond_code (cond); - rhs = gimple_cond_rhs (cond); + gcond *cond = as_a <gcond *> (last_stmt (cond_bb)); + enum tree_code cmp = gimple_cond_code (cond); + tree rhs = gimple_cond_rhs (cond); /* Turn EQ/NE of extreme values to order comparisons. */ if ((cmp == NE_EXPR || cmp == EQ_EXPR) @@ -1401,8 +1400,8 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb, /* This transformation is only valid for order comparisons. Record which operand is smaller/larger if the result of the comparison is true. */ - alt_smaller = NULL_TREE; - alt_larger = NULL_TREE; + tree alt_smaller = NULL_TREE; + tree alt_larger = NULL_TREE; if (cmp == LT_EXPR || cmp == LE_EXPR) { smaller = gimple_cond_lhs (cond); @@ -1463,6 +1462,50 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb, else return false; + /* Handle the special case of (signed_type)x < 0 being equivalent + to x > MAX_VAL(signed_type) and (signed_type)x >= 0 equivalent + to x <= MAX_VAL(signed_type). */ + if ((cmp == GE_EXPR || cmp == LT_EXPR) + && INTEGRAL_TYPE_P (type) + && TYPE_UNSIGNED (type) + && integer_zerop (rhs)) + { + tree op = gimple_cond_lhs (cond); + if (TREE_CODE (op) == SSA_NAME + && INTEGRAL_TYPE_P (TREE_TYPE (op)) + && !TYPE_UNSIGNED (TREE_TYPE (op))) + { + gimple *def_stmt = SSA_NAME_DEF_STMT (op); + if (gimple_assign_cast_p (def_stmt)) + { + tree op1 = gimple_assign_rhs1 (def_stmt); + if (INTEGRAL_TYPE_P (TREE_TYPE (op1)) + && TYPE_UNSIGNED (TREE_TYPE (op1)) + && (TYPE_PRECISION (TREE_TYPE (op)) + == TYPE_PRECISION (TREE_TYPE (op1))) + && useless_type_conversion_p (type, TREE_TYPE (op1))) + { + wide_int w1 = wi::max_value (TREE_TYPE (op)); + wide_int w2 = wi::add (w1, 1); + if (cmp == LT_EXPR) + { + larger = op1; + smaller = wide_int_to_tree (TREE_TYPE (op1), w1); + alt_smaller = wide_int_to_tree (TREE_TYPE (op1), w2); + alt_larger = NULL_TREE; + } + else + { + smaller = op1; + larger = wide_int_to_tree (TREE_TYPE (op1), w1); + alt_larger = wide_int_to_tree (TREE_TYPE (op1), w2); + alt_smaller = NULL_TREE; + } + } + } + } + } + /* We need to know which is the true edge and which is the false edge so that we know if have abs or negative abs. */ extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); |