On Thu, Jan 30, 2020 at 5:19 PM David Malcolm <dmalc...@redhat.com> wrote:
>
> Various places in the analyzer use fold_build2, test the result, then
> discard it. It's more efficient to use fold_binary, which avoids
> building and GC-ing a redundant tree for the cases where folding fails.
If these are all true integer constants, then you might want to use
tree_int_cst_compare instead of even using fold_binary/fold_build2.
Also if you are doing equal but always constant (but not always
integer ones), you could use simple_cst_equal instead.
Thanks,
Andrew Pinski
>
> gcc/analyzer/ChangeLog:
> * constraint-manager.cc (range::constrained_to_single_element):
> Replace fold_build2 with fold_binary. Remove unnecessary newline.
> (constraint_manager::get_or_add_equiv_class): Replace fold_build2
> with fold_binary in two places, and remove out-of-date comment.
> (constraint_manager::eval_condition): Replace fold_build2 with
> fold_binary.
> * region-model.cc (constant_svalue::eval_condition): Likewise.
> (region_model::on_assignment): Likewise.
> ---
> gcc/analyzer/constraint-manager.cc | 15 ++++++---------
> gcc/analyzer/region-model.cc | 6 +++---
> 2 files changed, 9 insertions(+), 12 deletions(-)
>
> diff --git a/gcc/analyzer/constraint-manager.cc
> b/gcc/analyzer/constraint-manager.cc
> index f3e31ee0830..4d138188856 100644
> --- a/gcc/analyzer/constraint-manager.cc
> +++ b/gcc/analyzer/constraint-manager.cc
> @@ -145,10 +145,9 @@ range::constrained_to_single_element (tree *out)
> m_upper_bound.ensure_closed (true);
>
> // Are they equal?
> - tree comparison
> - = fold_build2 (EQ_EXPR, boolean_type_node,
> - m_lower_bound.m_constant,
> - m_upper_bound.m_constant);
> + tree comparison = fold_binary (EQ_EXPR, boolean_type_node,
> + m_lower_bound.m_constant,
> + m_upper_bound.m_constant);
> if (comparison == boolean_true_node)
> {
> *out = m_lower_bound.m_constant;
> @@ -930,7 +929,7 @@ constraint_manager::get_or_add_equiv_class (svalue_id sid)
> FOR_EACH_VEC_ELT (m_equiv_classes, i, ec)
> if (ec->m_constant)
> {
> - tree eq = fold_build2 (EQ_EXPR, boolean_type_node,
> + tree eq = fold_binary (EQ_EXPR, boolean_type_node,
> cst, ec->m_constant);
> if (eq == boolean_true_node)
> {
> @@ -967,10 +966,8 @@ constraint_manager::get_or_add_equiv_class (svalue_id
> sid)
> Determine the direction of the inequality, and record that
> fact. */
> tree lt
> - = fold_build2 (LT_EXPR, boolean_type_node,
> + = fold_binary (LT_EXPR, boolean_type_node,
> new_ec->m_constant, other_ec.m_constant);
> - //gcc_assert (lt == boolean_true_node || lt ==
> boolean_false_node);
> - // not true for int vs float comparisons
> if (lt == boolean_true_node)
> add_constraint_internal (new_id, CONSTRAINT_LT, other_id);
> else if (lt == boolean_false_node)
> @@ -1016,7 +1013,7 @@ constraint_manager::eval_condition (equiv_class_id
> lhs_ec,
> if (lhs_const && rhs_const)
> {
> tree comparison
> - = fold_build2 (op, boolean_type_node, lhs_const, rhs_const);
> + = fold_binary (op, boolean_type_node, lhs_const, rhs_const);
> if (comparison == boolean_true_node)
> return tristate (tristate::TS_TRUE);
> if (comparison == boolean_false_node)
> diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-model.cc
> index b546114bfd5..95d002f9c28 100644
> --- a/gcc/analyzer/region-model.cc
> +++ b/gcc/analyzer/region-model.cc
> @@ -670,7 +670,7 @@ constant_svalue::eval_condition (constant_svalue *lhs,
> if (types_compatible_p (TREE_TYPE (lhs_const), TREE_TYPE (rhs_const)))
> {
> tree comparison
> - = fold_build2 (op, boolean_type_node, lhs_const, rhs_const);
> + = fold_binary (op, boolean_type_node, lhs_const, rhs_const);
> if (comparison == boolean_true_node)
> return tristate (tristate::TS_TRUE);
> if (comparison == boolean_false_node)
> @@ -4070,9 +4070,9 @@ region_model::on_assignment (const gassign *assign,
> region_model_context *ctxt)
> if (tree rhs1_cst = maybe_get_constant (rhs1_sid))
> if (tree rhs2_cst = maybe_get_constant (rhs2_sid))
> {
> - tree result = fold_build2 (op, TREE_TYPE (lhs),
> + tree result = fold_binary (op, TREE_TYPE (lhs),
> rhs1_cst, rhs2_cst);
> - if (CONSTANT_CLASS_P (result))
> + if (result && CONSTANT_CLASS_P (result))
> {
> svalue_id result_sid
> = get_or_create_constant_svalue (result);
> --
> 2.21.0
>
