On Fri, Nov 17, 2017 at 8:18 AM, Jeff Law <l...@redhat.com> wrote:
>
> As I've stated several times one of the goals here is to provide a
> little range analysis module that we can embed & reuse.
>
> To accomplish that I need to break down the evrp class.
>
> This patch does the bulk of the real work.
>
> evrp_dom_walker::before_dom_children is the key function we need to
> break down.
>
> It first extracts ranges from the incoming edge. Then it extracts
> ranges from phis & records which phis it's going to eliminate. Then it
> extracts ranges from statements and records which statements its going
> to eliminate.
>
> This pulls out 3 methods. One to extract ranges from the incoming edge,
> one to extract ranges from phis and one to extract ranges from a given
> statement and just calls them from evrp_dom_walker::before_dom_children.
>
>
> Bootstrapped and regression tested on x86_64.
>
> OK for the trunk?
Ok.
Richard.
> Jeff
>
>
> * gimple-ssa-evrp.c (evrp_dom_walker::record_ranges_from_phis): New
> method extracted from evrp_dom_walker::before_dom_children.
> (evrp_dom_walker::record_ranges_from_stmt): Likewise.
> (evrp_dom_walker::record_ranges_from_incoming_edge): Likewise.
>
> commit 56f691e91d8d815d81e606f65326601b850ef25c
> Author: Jeff Law <l...@torsion.usersys.redhat.com>
> Date: Fri Nov 17 00:07:18 2017 -0500
>
> record_ranges_from_incoming_edge
>
> diff --git a/gcc/gimple-ssa-evrp.c b/gcc/gimple-ssa-evrp.c
> index 952b31b..7b92beb 100644
> --- a/gcc/gimple-ssa-evrp.c
> +++ b/gcc/gimple-ssa-evrp.c
> @@ -80,6 +80,10 @@ public:
> value_range *pop_value_range (tree var);
> value_range *try_find_new_range (tree, tree op, tree_code code, tree
> limit);
>
> + void record_ranges_from_incoming_edge (basic_block);
> + void record_ranges_from_phis (basic_block);
> + void record_ranges_from_stmt (gimple *);
> +
> /* Cond_stack holds the old VR. */
> auto_vec<std::pair <tree, value_range*> > stack;
> bitmap need_eh_cleanup;
> @@ -150,17 +154,14 @@ evrp_dom_walker::try_find_new_range (tree name,
> return NULL;
> }
>
> -/* See if there is any new scope is entered with new VR and set that VR to
> - ssa_name before visiting the statements in the scope. */
> +/* If BB is reached by a single incoming edge (ignoring loop edges),
> + then derive ranges implied by traversing that edge. */
>
> -edge
> -evrp_dom_walker::before_dom_children (basic_block bb)
> +void
> +evrp_dom_walker::record_ranges_from_incoming_edge (basic_block bb)
> {
> - if (dump_file && (dump_flags & TDF_DETAILS))
> - fprintf (dump_file, "Visiting BB%d\n", bb->index);
> -
> - stack.safe_push (std::make_pair (NULL_TREE, (value_range *)NULL));
> -
> +/* See if there is any new scope is entered with new VR and set that VR to
> + ssa_name before visiting the statements in the scope. */
> edge pred_e = single_pred_edge_ignoring_loop_edges (bb, false);
> if (pred_e)
> {
> @@ -207,7 +208,13 @@ evrp_dom_walker::before_dom_children (basic_block bb)
> push_value_range (vrs[i].first, vrs[i].second);
> }
> }
> +}
> +
> +/* Record ranges from any PHI nodes at the start of basic block BB. */
>
> +void
> +evrp_dom_walker::record_ranges_from_phis (basic_block bb)
> +{
> /* Visit PHI stmts and discover any new VRs possible. */
> bool has_unvisited_preds = false;
> edge_iterator ei;
> @@ -252,14 +259,6 @@ evrp_dom_walker::before_dom_children (basic_block bb)
> }
> update_value_range (lhs, &vr_result);
>
> - /* Mark PHIs whose lhs we fully propagate for removal. */
> - tree val = op_with_constant_singleton_value_range (lhs);
> - if (val && may_propagate_copy (lhs, val))
> - {
> - stmts_to_remove.safe_push (phi);
> - continue;
> - }
> -
> /* Set the SSA with the value range. */
> if (INTEGRAL_TYPE_P (TREE_TYPE (lhs)))
> {
> @@ -280,6 +279,122 @@ evrp_dom_walker::before_dom_children (basic_block bb)
> vr_result.max) == 1)))
> set_ptr_nonnull (lhs);
> }
> +}
> +
> +/* Record any ranges created by statement STMT. */
> +
> +void
> +evrp_dom_walker::record_ranges_from_stmt (gimple *stmt)
> +{
> + tree output = NULL_TREE;
> +
> + if (dyn_cast <gcond *> (stmt))
> + ;
> + else if (stmt_interesting_for_vrp (stmt))
> + {
> + edge taken_edge;
> + value_range vr = VR_INITIALIZER;
> + extract_range_from_stmt (stmt, &taken_edge, &output, &vr);
> + if (output && (vr.type == VR_RANGE || vr.type == VR_ANTI_RANGE))
> + {
> + update_value_range (output, &vr);
> +
> + /* Set the SSA with the value range. */
> + if (INTEGRAL_TYPE_P (TREE_TYPE (output)))
> + {
> + if ((vr.type == VR_RANGE || vr.type == VR_ANTI_RANGE)
> + && (TREE_CODE (vr.min) == INTEGER_CST)
> + && (TREE_CODE (vr.max) == INTEGER_CST))
> + set_range_info (output, vr.type,
> + wi::to_wide (vr.min),
> + wi::to_wide (vr.max));
> + }
> + else if (POINTER_TYPE_P (TREE_TYPE (output))
> + && ((vr.type == VR_RANGE
> + && range_includes_zero_p (vr.min, vr.max) == 0)
> + || (vr.type == VR_ANTI_RANGE
> + && range_includes_zero_p (vr.min, vr.max) == 1)))
> + set_ptr_nonnull (output);
> + }
> + else
> + set_defs_to_varying (stmt);
> + }
> + else
> + set_defs_to_varying (stmt);
> +
> + /* See if we can derive a range for any of STMT's operands. */
> + tree op;
> + ssa_op_iter i;
> + FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_USE)
> + {
> + tree value;
> + enum tree_code comp_code;
> +
> + /* If OP is used in such a way that we can infer a value
> + range for it, and we don't find a previous assertion for
> + it, create a new assertion location node for OP. */
> + if (infer_value_range (stmt, op, &comp_code, &value))
> + {
> + /* If we are able to infer a nonzero value range for OP,
> + then walk backwards through the use-def chain to see if OP
> + was set via a typecast.
> + If so, then we can also infer a nonzero value range
> + for the operand of the NOP_EXPR. */
> + if (comp_code == NE_EXPR && integer_zerop (value))
> + {
> + tree t = op;
> + gimple *def_stmt = SSA_NAME_DEF_STMT (t);
> + while (is_gimple_assign (def_stmt)
> + && CONVERT_EXPR_CODE_P (gimple_assign_rhs_code
> (def_stmt))
> + && TREE_CODE (gimple_assign_rhs1 (def_stmt)) == SSA_NAME
> + && POINTER_TYPE_P
> + (TREE_TYPE (gimple_assign_rhs1 (def_stmt))))
> + {
> + t = gimple_assign_rhs1 (def_stmt);
> + def_stmt = SSA_NAME_DEF_STMT (t);
> +
> + /* Add VR when (T COMP_CODE value) condition is true. */
> + value_range *op_range
> + = try_find_new_range (t, t, comp_code, value);
> + if (op_range)
> + push_value_range (t, op_range);
> + }
> + }
> + /* Add VR when (OP COMP_CODE value) condition is true. */
> + value_range *op_range = try_find_new_range (op, op,
> + comp_code, value);
> + if (op_range)
> + push_value_range (op, op_range);
> + }
> + }
> +}
> +
> +edge
> +evrp_dom_walker::before_dom_children (basic_block bb)
> +{
> + if (dump_file && (dump_flags & TDF_DETAILS))
> + fprintf (dump_file, "Visiting BB%d\n", bb->index);
> +
> + stack.safe_push (std::make_pair (NULL_TREE, (value_range *)NULL));
> + record_ranges_from_incoming_edge (bb);
> + record_ranges_from_phis (bb);
> +
> + for (gphi_iterator gpi = gsi_start_phis (bb);
> + !gsi_end_p (gpi); gsi_next (&gpi))
> + {
> + gphi *phi = gpi.phi ();
> + tree lhs = PHI_RESULT (phi);
> + if (virtual_operand_p (lhs))
> + continue;
> +
> + /* Mark PHIs whose lhs we fully propagate for removal. */
> + tree val = op_with_constant_singleton_value_range (lhs);
> + if (val && may_propagate_copy (lhs, val))
> + {
> + stmts_to_remove.safe_push (phi);
> + continue;
> + }
> + }
>
> edge taken_edge = NULL;
>
> @@ -299,6 +414,7 @@ evrp_dom_walker::before_dom_children (basic_block bb)
> print_gimple_stmt (dump_file, stmt, 0);
> }
>
> + record_ranges_from_stmt (stmt);
> if (gcond *cond = dyn_cast <gcond *> (stmt))
> {
> vrp_visit_cond_stmt (cond, &taken_edge);
> @@ -315,18 +431,16 @@ evrp_dom_walker::before_dom_children (basic_block bb)
> }
> else if (stmt_interesting_for_vrp (stmt))
> {
> - edge taken_edge;
> value_range vr = VR_INITIALIZER;
> - extract_range_from_stmt (stmt, &taken_edge, &output, &vr);
> - if (output
> - && (vr.type == VR_RANGE || vr.type == VR_ANTI_RANGE))
> + output = get_output_for_vrp (stmt);
> + if (output)
> {
> - update_value_range (output, &vr);
> vr = *get_value_range (output);
>
> /* Mark stmts whose output we fully propagate for removal. */
> tree val;
> - if ((val = op_with_constant_singleton_value_range (output))
> + if ((vr.type == VR_RANGE || vr.type == VR_ANTI_RANGE)
> + && (val = op_with_constant_singleton_value_range (output))
> && may_propagate_copy (output, val)
> && !stmt_could_throw_p (stmt)
> && !gimple_has_side_effects (stmt))
> @@ -334,79 +448,6 @@ evrp_dom_walker::before_dom_children (basic_block bb)
> stmts_to_remove.safe_push (stmt);
> continue;
> }
> -
> - /* Set the SSA with the value range. */
> - if (INTEGRAL_TYPE_P (TREE_TYPE (output)))
> - {
> - if ((vr.type == VR_RANGE
> - || vr.type == VR_ANTI_RANGE)
> - && (TREE_CODE (vr.min) == INTEGER_CST)
> - && (TREE_CODE (vr.max) == INTEGER_CST))
> - set_range_info (output, vr.type,
> - wi::to_wide (vr.min),
> - wi::to_wide (vr.max));
> - }
> - else if (POINTER_TYPE_P (TREE_TYPE (output))
> - && ((vr.type == VR_RANGE
> - && range_includes_zero_p (vr.min,
> - vr.max) == 0)
> - || (vr.type == VR_ANTI_RANGE
> - && range_includes_zero_p (vr.min,
> - vr.max) == 1)))
> - set_ptr_nonnull (output);
> - }
> - else
> - set_defs_to_varying (stmt);
> - }
> - else
> - set_defs_to_varying (stmt);
> -
> - /* See if we can derive a range for any of STMT's operands. */
> - tree op;
> - ssa_op_iter i;
> - FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_USE)
> - {
> - tree value;
> - enum tree_code comp_code;
> -
> - /* If OP is used in such a way that we can infer a value
> - range for it, and we don't find a previous assertion for
> - it, create a new assertion location node for OP. */
> - if (infer_value_range (stmt, op, &comp_code, &value))
> - {
> - /* If we are able to infer a nonzero value range for OP,
> - then walk backwards through the use-def chain to see if OP
> - was set via a typecast.
> - If so, then we can also infer a nonzero value range
> - for the operand of the NOP_EXPR. */
> - if (comp_code == NE_EXPR && integer_zerop (value))
> - {
> - tree t = op;
> - gimple *def_stmt = SSA_NAME_DEF_STMT (t);
> - while (is_gimple_assign (def_stmt)
> - && CONVERT_EXPR_CODE_P
> - (gimple_assign_rhs_code (def_stmt))
> - && TREE_CODE
> - (gimple_assign_rhs1 (def_stmt)) == SSA_NAME
> - && POINTER_TYPE_P
> - (TREE_TYPE (gimple_assign_rhs1 (def_stmt))))
> - {
> - t = gimple_assign_rhs1 (def_stmt);
> - def_stmt = SSA_NAME_DEF_STMT (t);
> -
> - /* Add VR when (T COMP_CODE value) condition is
> - true. */
> - value_range *op_range
> - = try_find_new_range (t, t, comp_code, value);
> - if (op_range)
> - push_value_range (t, op_range);
> - }
> - }
> - /* Add VR when (OP COMP_CODE value) condition is true. */
> - value_range *op_range = try_find_new_range (op, op,
> - comp_code, value);
> - if (op_range)
> - push_value_range (op, op_range);
> }
> }
>
> @@ -446,6 +487,8 @@ evrp_dom_walker::before_dom_children (basic_block bb)
> }
>
> /* Visit BB successor PHI nodes and replace PHI args. */
> + edge e;
> + edge_iterator ei;
> FOR_EACH_EDGE (e, ei, bb->succs)
> {
> for (gphi_iterator gpi = gsi_start_phis (e->dest);
>
