/* Support routines for Value Range Propagation (VRP).
- Copyright (C) 2005-2017 Free Software Foundation, Inc.
+ Copyright (C) 2005-2019 Free Software Foundation, Inc.
This file is part of GCC.
#include "domwalk.h"
#include "tree-cfgcleanup.h"
#include "vr-values.h"
+#include "gimple-ssa-evrp-analyze.h"
class evrp_folder : public substitute_and_fold_engine
{
public:
tree get_value (tree) FINAL OVERRIDE;
-
+ evrp_folder (class vr_values *vr_values_) : vr_values (vr_values_) { }
+ bool simplify_stmt_using_ranges (gimple_stmt_iterator *gsi)
+ { return vr_values->simplify_stmt_using_ranges (gsi); }
class vr_values *vr_values;
+
+ private:
+ DISABLE_COPY_AND_ASSIGN (evrp_folder);
};
tree
{
public:
evrp_dom_walker ()
- : dom_walker (CDI_DOMINATORS), stack (10)
+ : dom_walker (CDI_DOMINATORS),
+ evrp_range_analyzer (true),
+ evrp_folder (evrp_range_analyzer.get_vr_values ())
{
need_eh_cleanup = BITMAP_ALLOC (NULL);
}
}
virtual edge before_dom_children (basic_block);
virtual void after_dom_children (basic_block);
- void push_value_range (tree var, value_range *vr);
- value_range *pop_value_range (tree var);
- value_range *try_find_new_range (tree, tree op, tree_code code, tree limit);
+ void cleanup (void);
- /* Cond_stack holds the old VR. */
- auto_vec<std::pair <tree, value_range*> > stack;
+ private:
+ DISABLE_COPY_AND_ASSIGN (evrp_dom_walker);
bitmap need_eh_cleanup;
auto_vec<gimple *> stmts_to_fixup;
auto_vec<gimple *> stmts_to_remove;
- class vr_values vr_values;
-
- /* Temporary delegators. */
- value_range *get_value_range (const_tree op)
- { return vr_values.get_value_range (op); }
- bool update_value_range (const_tree op, value_range *vr)
- { return vr_values.update_value_range (op, vr); }
- void extract_range_from_phi_node (gphi *phi, value_range *vr)
- { vr_values.extract_range_from_phi_node (phi, vr); }
- void extract_range_for_var_from_comparison_expr (tree var,
- enum tree_code cond_code,
- tree op, tree limit,
- value_range *vr_p)
- { vr_values.extract_range_for_var_from_comparison_expr (var, cond_code,
- op, limit, vr_p); }
- void adjust_range_with_scev (value_range *vr, struct loop *loop,
- gimple *stmt, tree var)
- { vr_values.adjust_range_with_scev (vr, loop, stmt, var); }
- tree op_with_constant_singleton_value_range (tree op)
- { return vr_values.op_with_constant_singleton_value_range (op); }
- void extract_range_from_stmt (gimple *stmt, edge *taken_edge_p,
- tree *output_p, value_range *vr)
- { vr_values.extract_range_from_stmt (stmt, taken_edge_p, output_p, vr); }
- void set_defs_to_varying (gimple *stmt)
- { return vr_values.set_defs_to_varying (stmt); }
- void set_vr_value (tree name, value_range *vr)
- { vr_values.set_vr_value (name, vr); }
- void simplify_cond_using_ranges_2 (gcond *stmt)
- { vr_values.simplify_cond_using_ranges_2 (stmt); }
- void vrp_visit_cond_stmt (gcond *cond, edge *e)
- { vr_values.vrp_visit_cond_stmt (cond, e); }
+ class evrp_range_analyzer evrp_range_analyzer;
+ class evrp_folder evrp_folder;
};
-/* Find new range for NAME such that (OP CODE LIMIT) is true. */
-
-value_range *
-evrp_dom_walker::try_find_new_range (tree name,
- tree op, tree_code code, tree limit)
-{
- value_range vr = VR_INITIALIZER;
- value_range *old_vr = get_value_range (name);
-
- /* Discover VR when condition is true. */
- extract_range_for_var_from_comparison_expr (name, code, op,
- limit, &vr);
- /* If we found any usable VR, set the VR to ssa_name and create a
- PUSH old value in the stack with the old VR. */
- if (vr.type == VR_RANGE || vr.type == VR_ANTI_RANGE)
- {
- if (old_vr->type == vr.type
- && vrp_operand_equal_p (old_vr->min, vr.min)
- && vrp_operand_equal_p (old_vr->max, vr.max))
- return NULL;
- value_range *new_vr = vr_values.vrp_value_range_pool.allocate ();
- *new_vr = vr;
- return new_vr;
- }
- 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. */
-
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));
-
- edge pred_e = single_pred_edge_ignoring_loop_edges (bb, false);
- if (pred_e)
- {
- gimple *stmt = last_stmt (pred_e->src);
- tree op0 = NULL_TREE;
-
- if (stmt
- && gimple_code (stmt) == GIMPLE_COND
- && (op0 = gimple_cond_lhs (stmt))
- && TREE_CODE (op0) == SSA_NAME
- && (INTEGRAL_TYPE_P (TREE_TYPE (gimple_cond_lhs (stmt)))
- || POINTER_TYPE_P (TREE_TYPE (gimple_cond_lhs (stmt)))))
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Visiting controlling predicate ");
- print_gimple_stmt (dump_file, stmt, 0);
- }
- /* Entering a new scope. Try to see if we can find a VR
- here. */
- tree op1 = gimple_cond_rhs (stmt);
- if (TREE_OVERFLOW_P (op1))
- op1 = drop_tree_overflow (op1);
- tree_code code = gimple_cond_code (stmt);
-
- auto_vec<assert_info, 8> asserts;
- register_edge_assert_for (op0, pred_e, code, op0, op1, asserts);
- if (TREE_CODE (op1) == SSA_NAME)
- register_edge_assert_for (op1, pred_e, code, op0, op1, asserts);
-
- auto_vec<std::pair<tree, value_range *>, 8> vrs;
- for (unsigned i = 0; i < asserts.length (); ++i)
- {
- value_range *vr = try_find_new_range (asserts[i].name,
- asserts[i].expr,
- asserts[i].comp_code,
- asserts[i].val);
- if (vr)
- vrs.safe_push (std::make_pair (asserts[i].name, vr));
- }
- /* Push updated ranges only after finding all of them to avoid
- ordering issues that can lead to worse ranges. */
- for (unsigned i = 0; i < vrs.length (); ++i)
- push_value_range (vrs[i].first, vrs[i].second);
- }
- }
-
- /* Visit PHI stmts and discover any new VRs possible. */
- bool has_unvisited_preds = false;
- edge_iterator ei;
- edge e;
- FOR_EACH_EDGE (e, ei, bb->preds)
- if (e->flags & EDGE_EXECUTABLE
- && !(e->src->flags & BB_VISITED))
- {
- has_unvisited_preds = true;
- break;
- }
+ evrp_range_analyzer.enter (bb);
for (gphi_iterator gpi = gsi_start_phis (bb);
!gsi_end_p (gpi); gsi_next (&gpi))
tree lhs = PHI_RESULT (phi);
if (virtual_operand_p (lhs))
continue;
- value_range vr_result = VR_INITIALIZER;
- bool interesting = stmt_interesting_for_vrp (phi);
- if (interesting && dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Visiting PHI node ");
- print_gimple_stmt (dump_file, phi, 0);
- }
- if (!has_unvisited_preds
- && interesting)
- extract_range_from_phi_node (phi, &vr_result);
- else
- {
- set_value_range_to_varying (&vr_result);
- /* When we have an unvisited executable predecessor we can't
- use PHI arg ranges which may be still UNDEFINED but have
- to use VARYING for them. But we can still resort to
- SCEV for loop header PHIs. */
- struct loop *l;
- if (interesting
- && (l = loop_containing_stmt (phi))
- && l->header == gimple_bb (phi))
- adjust_range_with_scev (&vr_result, l, phi, lhs);
- }
- update_value_range (lhs, &vr_result);
+ value_range *vr = evrp_range_analyzer.get_value_range (lhs);
/* 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))
+ tree val;
+ if (vr->singleton_p (&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)))
- {
- if ((vr_result.type == VR_RANGE
- || vr_result.type == VR_ANTI_RANGE)
- && (TREE_CODE (vr_result.min) == INTEGER_CST)
- && (TREE_CODE (vr_result.max) == INTEGER_CST))
- set_range_info (lhs, vr_result.type,
- wi::to_wide (vr_result.min),
- wi::to_wide (vr_result.max));
- }
- else if (POINTER_TYPE_P (TREE_TYPE (lhs))
- && ((vr_result.type == VR_RANGE
- && range_includes_zero_p (vr_result.min,
- vr_result.max) == 0)
- || (vr_result.type == VR_ANTI_RANGE
- && range_includes_zero_p (vr_result.min,
- vr_result.max) == 1)))
- set_ptr_nonnull (lhs);
}
edge taken_edge = NULL;
print_gimple_stmt (dump_file, stmt, 0);
}
+ evrp_range_analyzer.record_ranges_from_stmt (stmt, false);
+
if (gcond *cond = dyn_cast <gcond *> (stmt))
{
- vrp_visit_cond_stmt (cond, &taken_edge);
+ evrp_range_analyzer.vrp_visit_cond_stmt (cond, &taken_edge);
if (taken_edge)
{
if (taken_edge->flags & EDGE_TRUE_VALUE)
}
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);
+ tree val;
+ value_range *vr = evrp_range_analyzer.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->singleton_p (&val)
&& may_propagate_copy (output, val)
- && !stmt_could_throw_p (stmt)
+ && !stmt_could_throw_p (cfun, stmt)
&& !gimple_has_side_effects (stmt))
{
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);
}
}
/* Try folding stmts with the VR discovered. */
- class evrp_folder evrp_folder;
- evrp_folder.vr_values = &vr_values;
bool did_replace = evrp_folder.replace_uses_in (stmt);
+ gimple_stmt_iterator prev_gsi = gsi;
+ gsi_prev (&prev_gsi);
if (fold_stmt (&gsi, follow_single_use_edges)
|| did_replace)
{
update_stmt (stmt);
did_replace = true;
}
+ if (evrp_folder.simplify_stmt_using_ranges (&gsi))
+ {
+ stmt = gsi_stmt (gsi);
+ update_stmt (stmt);
+ did_replace = true;
+ }
if (did_replace)
{
+ /* If we wound up generating new stmts during folding
+ drop all their defs to VARYING. We can't easily
+ process them because we've already instantiated
+ ranges on uses on STMT that only hold after it. */
+ if (gsi_end_p (prev_gsi))
+ prev_gsi = gsi_start_bb (bb);
+ else
+ gsi_next (&prev_gsi);
+ while (gsi_stmt (prev_gsi) != gsi_stmt (gsi))
+ {
+ evrp_range_analyzer.get_vr_values ()
+ ->set_defs_to_varying (gsi_stmt (prev_gsi));
+ gsi_next (&prev_gsi);
+ }
+
/* If we cleaned up EH information from the statement,
remove EH edges. */
if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt))
}
/* 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);
if (TREE_CODE (arg) != SSA_NAME
|| virtual_operand_p (arg))
continue;
- tree val = op_with_constant_singleton_value_range (arg);
- if (val && may_propagate_copy (arg, val))
+ value_range *vr = evrp_range_analyzer.get_value_range (arg);
+ tree val;
+ if (vr->singleton_p (&val) && may_propagate_copy (arg, val))
propagate_value (use_p, val);
}
}
- bb->flags |= BB_VISITED;
-
return taken_edge;
}
-/* Restore/pop VRs valid only for BB when we leave BB. */
-
void
-evrp_dom_walker::after_dom_children (basic_block bb ATTRIBUTE_UNUSED)
+evrp_dom_walker::after_dom_children (basic_block bb)
{
- gcc_checking_assert (!stack.is_empty ());
- while (stack.last ().first != NULL_TREE)
- pop_value_range (stack.last ().first);
- stack.pop ();
+ evrp_range_analyzer.leave (bb);
}
-/* Push the Value Range of VAR to the stack and update it with new VR. */
+/* Perform any cleanups after the main phase of EVRP has completed. */
void
-evrp_dom_walker::push_value_range (tree var, value_range *vr)
-{
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "pushing new range for ");
- print_generic_expr (dump_file, var);
- fprintf (dump_file, ": ");
- dump_value_range (dump_file, vr);
- fprintf (dump_file, "\n");
- }
- stack.safe_push (std::make_pair (var, get_value_range (var)));
- set_vr_value (var, vr);
-}
-
-/* Pop the Value Range from the vrp_stack and update VAR with it. */
-
-value_range *
-evrp_dom_walker::pop_value_range (tree var)
-{
- value_range *vr = stack.last ().second;
- gcc_checking_assert (var == stack.last ().first);
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "popping range for ");
- print_generic_expr (dump_file, var);
- fprintf (dump_file, ", restoring ");
- dump_value_range (dump_file, vr);
- fprintf (dump_file, "\n");
- }
- set_vr_value (var, vr);
- stack.pop ();
- return vr;
-}
-
-
-/* Main entry point for the early vrp pass which is a simplified non-iterative
- version of vrp where basic blocks are visited in dominance order. Value
- ranges discovered in early vrp will also be used by ipa-vrp. */
-
-static unsigned int
-execute_early_vrp ()
+evrp_dom_walker::cleanup (void)
{
- edge e;
- edge_iterator ei;
- basic_block bb;
-
- loop_optimizer_init (LOOPS_NORMAL | LOOPS_HAVE_RECORDED_EXITS);
- rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
- scev_initialize ();
- calculate_dominance_info (CDI_DOMINATORS);
- FOR_EACH_BB_FN (bb, cfun)
- {
- bb->flags &= ~BB_VISITED;
- FOR_EACH_EDGE (e, ei, bb->preds)
- e->flags |= EDGE_EXECUTABLE;
- }
-
- /* Walk stmts in dominance order and propagate VRP. */
- evrp_dom_walker walker;
- walker.walk (ENTRY_BLOCK_PTR_FOR_FN (cfun));
-
if (dump_file)
{
fprintf (dump_file, "\nValue ranges after Early VRP:\n\n");
- walker.vr_values.dump_all_value_ranges (dump_file);
+ evrp_range_analyzer.dump_all_value_ranges (dump_file);
fprintf (dump_file, "\n");
}
/* Remove stmts in reverse order to make debug stmt creation possible. */
- while (! walker.stmts_to_remove.is_empty ())
+ while (! stmts_to_remove.is_empty ())
{
- gimple *stmt = walker.stmts_to_remove.pop ();
+ gimple *stmt = stmts_to_remove.pop ();
if (dump_file && dump_flags & TDF_DETAILS)
{
fprintf (dump_file, "Removing dead stmt ");
}
}
- if (!bitmap_empty_p (walker.need_eh_cleanup))
- gimple_purge_all_dead_eh_edges (walker.need_eh_cleanup);
+ if (!bitmap_empty_p (need_eh_cleanup))
+ gimple_purge_all_dead_eh_edges (need_eh_cleanup);
/* Fixup stmts that became noreturn calls. This may require splitting
blocks and thus isn't possible during the dominator walk. Do this
in reverse order so we don't inadvertedly remove a stmt we want to
fixup by visiting a dominating now noreturn call first. */
- while (!walker.stmts_to_fixup.is_empty ())
+ while (!stmts_to_fixup.is_empty ())
{
- gimple *stmt = walker.stmts_to_fixup.pop ();
+ gimple *stmt = stmts_to_fixup.pop ();
fixup_noreturn_call (stmt);
}
+ evrp_folder.vr_values->cleanup_edges_and_switches ();
+}
+
+/* Main entry point for the early vrp pass which is a simplified non-iterative
+ version of vrp where basic blocks are visited in dominance order. Value
+ ranges discovered in early vrp will also be used by ipa-vrp. */
+
+static unsigned int
+execute_early_vrp ()
+{
+ /* Ideally this setup code would move into the ctor for the dominator
+ walk. However, this setup can change the number of blocks which
+ invalidates the internal arrays that are set up by the dominator
+ walker. */
+ loop_optimizer_init (LOOPS_NORMAL | LOOPS_HAVE_RECORDED_EXITS);
+ rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
+ scev_initialize ();
+ calculate_dominance_info (CDI_DOMINATORS);
+
+ /* Walk stmts in dominance order and propagate VRP. */
+ evrp_dom_walker walker;
+ walker.walk (ENTRY_BLOCK_PTR_FOR_FN (cfun));
+ walker.cleanup ();
+
scev_finalize ();
loop_optimizer_finalize ();
return 0;
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