@@ -1698,6 +1698,7 @@ OBJS = \
typed-splay-tree.o \
unique-ptr-tests.o \
valtrack.o \
+ value-pointer-equiv.o \
value-query.o \
value-range.o \
value-range-equiv.o \
@@ -43,299 +43,7 @@ along with GCC; see the file COPYING3. If not see
#include "gimple-ssa-evrp-analyze.h"
#include "gimple-range.h"
#include "fold-const.h"
-
-// Unwindable SSA equivalence table for pointers.
-//
-// The main query point is get_replacement() which returns what a
-// given SSA can be replaced with in the current scope.
-
-class ssa_equiv_stack
-{
-public:
- ssa_equiv_stack ();
- void enter (basic_block);
- void leave (basic_block);
- void push_replacement (tree name, tree replacement);
- tree get_replacement (tree name) const;
-
-private:
- auto_vec<std::pair <tree, tree>> m_stack;
- auto_vec<tree> m_replacements;
- const std::pair <tree, tree> m_marker = std::make_pair (NULL, NULL);
-};
-
-ssa_equiv_stack::ssa_equiv_stack ()
-{
- m_replacements.safe_grow_cleared (num_ssa_names);
-}
-
-// Pushes a marker at the given point.
-
-void
-ssa_equiv_stack::enter (basic_block)
-{
- m_stack.safe_push (m_marker);
-}
-
-// Pops the stack to the last marker, while performing replacements
-// along the way.
-
-void
-ssa_equiv_stack::leave (basic_block)
-{
- gcc_checking_assert (!m_stack.is_empty ());
- while (m_stack.last () != m_marker)
- {
- std::pair<tree, tree> e = m_stack.pop ();
- m_replacements[SSA_NAME_VERSION (e.first)] = e.second;
- }
- m_stack.pop ();
-}
-
-// Set the equivalence of NAME to REPLACEMENT.
-
-void
-ssa_equiv_stack::push_replacement (tree name, tree replacement)
-{
- tree old = m_replacements[SSA_NAME_VERSION (name)];
- m_replacements[SSA_NAME_VERSION (name)] = replacement;
- m_stack.safe_push (std::make_pair (name, old));
-}
-
-// Return the equivalence of NAME.
-
-tree
-ssa_equiv_stack::get_replacement (tree name) const
-{
- return m_replacements[SSA_NAME_VERSION (name)];
-}
-
-// Return TRUE if EXPR is an SSA holding a pointer.
-
-static bool inline
-is_pointer_ssa (tree expr)
-{
- return TREE_CODE (expr) == SSA_NAME && POINTER_TYPE_P (TREE_TYPE (expr));
-}
-
-// Simple context-aware pointer equivalency analyzer that returns what
-// a pointer SSA name is equivalent to at a given point during a walk
-// of the IL.
-//
-// Note that global equivalency take priority over conditional
-// equivalency. That is, p = &q takes priority over a later p == &t.
-//
-// This class is meant to be called during a DOM walk.
-
-class pointer_equiv_analyzer
-{
-public:
- pointer_equiv_analyzer (gimple_ranger *r);
- ~pointer_equiv_analyzer ();
- void enter (basic_block);
- void leave (basic_block);
- void visit_stmt (gimple *stmt);
- tree get_equiv (tree ssa) const;
-
-private:
- void visit_edge (edge e);
- tree get_equiv_expr (tree_code code, tree expr) const;
- void set_global_equiv (tree ssa, tree pointee);
- void set_cond_equiv (tree ssa, tree pointee);
-
- gimple_ranger *m_ranger;
- // Global pointer equivalency indexed by SSA_NAME_VERSION.
- tree *m_global_points;
- // Conditional pointer equivalency.
- ssa_equiv_stack m_cond_points;
-};
-
-pointer_equiv_analyzer::pointer_equiv_analyzer (gimple_ranger *r)
-{
- m_ranger = r;
- m_global_points = new tree[num_ssa_names] ();
-}
-
-pointer_equiv_analyzer::~pointer_equiv_analyzer ()
-{
- delete[] m_global_points;
-}
-
-// Set the global pointer equivalency for SSA to POINTEE.
-
-void
-pointer_equiv_analyzer::set_global_equiv (tree ssa, tree pointee)
-{
- m_global_points[SSA_NAME_VERSION (ssa)] = pointee;
-}
-
-// Set the conditional pointer equivalency for SSA to POINTEE.
-
-void
-pointer_equiv_analyzer::set_cond_equiv (tree ssa, tree pointee)
-{
- m_cond_points.push_replacement (ssa, pointee);
-}
-
-// Return the current pointer equivalency info for SSA, or NULL if
-// none is available. Note that global info takes priority over
-// conditional info.
-
-tree
-pointer_equiv_analyzer::get_equiv (tree ssa) const
-{
- tree ret = m_global_points[SSA_NAME_VERSION (ssa)];
- if (ret)
- return ret;
- return m_cond_points.get_replacement (ssa);
-}
-
-// Method to be called on entry to a BB.
-
-void
-pointer_equiv_analyzer::enter (basic_block bb)
-{
- m_cond_points.enter (bb);
-
- for (gphi_iterator iter = gsi_start_phis (bb);
- !gsi_end_p (iter);
- gsi_next (&iter))
- {
- gphi *phi = iter.phi ();
- tree lhs = gimple_phi_result (phi);
- if (!POINTER_TYPE_P (TREE_TYPE (lhs)))
- continue;
- tree arg0 = gimple_phi_arg_def (phi, 0);
- if (TREE_CODE (arg0) == SSA_NAME && !is_gimple_min_invariant (arg0))
- arg0 = get_equiv (arg0);
- if (arg0 && is_gimple_min_invariant (arg0))
- {
- // If all the PHI args point to the same place, set the
- // pointer equivalency info for the PHI result. This can
- // happen for passes that create redundant PHIs like
- // PHI<&foo, &foo> or PHI<&foo>.
- for (size_t i = 1; i < gimple_phi_num_args (phi); ++i)
- {
- tree argi = gimple_phi_arg_def (phi, i);
- if (TREE_CODE (argi) == SSA_NAME
- && !is_gimple_min_invariant (argi))
- argi = get_equiv (argi);
- if (!argi || !operand_equal_p (arg0, argi))
- return;
- }
- set_global_equiv (lhs, arg0);
- }
- }
-
- edge pred = single_pred_edge_ignoring_loop_edges (bb, false);
- if (pred)
- visit_edge (pred);
-}
-
-// Method to be called on exit from a BB.
-
-void
-pointer_equiv_analyzer::leave (basic_block bb)
-{
- m_cond_points.leave (bb);
-}
-
-// Helper function to return the pointer equivalency information for
-// EXPR from a gimple statement with CODE. This returns either the
-// cached pointer equivalency info for an SSA, or an invariant in case
-// EXPR is one (i.e. &foo). Returns NULL if EXPR is neither an SSA
-// nor an invariant.
-
-tree
-pointer_equiv_analyzer::get_equiv_expr (tree_code code, tree expr) const
-{
- if (code == SSA_NAME)
- return get_equiv (expr);
-
- if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS
- && is_gimple_min_invariant (expr))
- return expr;
-
- return NULL;
-}
-
-// Hack to provide context to the gimple fold callback.
-static struct
-{
- gimple *m_stmt;
- gimple_ranger *m_ranger;
- pointer_equiv_analyzer *m_pta;
-} x_fold_context;
-
-// Gimple fold callback.
-static tree
-pta_valueize (tree name)
-{
- tree ret
- = x_fold_context.m_ranger->value_of_expr (name, x_fold_context.m_stmt);
-
- if (!ret && is_pointer_ssa (name))
- ret = x_fold_context.m_pta->get_equiv (name);
-
- return ret ? ret : name;
-}
-
-// Method to be called on gimple statements during traversal of the IL.
-
-void
-pointer_equiv_analyzer::visit_stmt (gimple *stmt)
-{
- if (gimple_code (stmt) != GIMPLE_ASSIGN)
- return;
-
- tree lhs = gimple_assign_lhs (stmt);
- if (!is_pointer_ssa (lhs))
- return;
-
- tree rhs = gimple_assign_rhs1 (stmt);
- rhs = get_equiv_expr (gimple_assign_rhs_code (stmt), rhs);
- if (rhs)
- {
- set_global_equiv (lhs, rhs);
- return;
- }
-
- // If we couldn't find anything, try fold.
- x_fold_context = { stmt, m_ranger, this};
- rhs = gimple_fold_stmt_to_constant_1 (stmt, pta_valueize, pta_valueize);
- if (rhs)
- {
- rhs = get_equiv_expr (TREE_CODE (rhs), rhs);
- if (rhs)
- {
- set_global_equiv (lhs, rhs);
- return;
- }
- }
-}
-
-// If the edge in E is a conditional that sets a pointer equality, set the
-// conditional pointer equivalency information.
-
-void
-pointer_equiv_analyzer::visit_edge (edge e)
-{
- gimple *stmt = last_stmt (e->src);
- tree lhs;
- // Recognize: x_13 [==,!=] &foo.
- if (stmt
- && gimple_code (stmt) == GIMPLE_COND
- && (lhs = gimple_cond_lhs (stmt))
- && TREE_CODE (lhs) == SSA_NAME
- && POINTER_TYPE_P (TREE_TYPE (lhs))
- && TREE_CODE (gimple_cond_rhs (stmt)) == ADDR_EXPR)
- {
- tree_code code = gimple_cond_code (stmt);
- if ((code == EQ_EXPR && e->flags & EDGE_TRUE_VALUE)
- || ((code == NE_EXPR && e->flags & EDGE_FALSE_VALUE)))
- set_cond_equiv (lhs, gimple_cond_rhs (stmt));
- }
-}
+#include "value-pointer-equiv.h"
// This is the classic EVRP folder which uses a dominator walk and pushes
// ranges into the next block if it is a single predecessor block.
@@ -430,7 +138,7 @@ public:
tree value_of_expr (tree name, gimple *s = NULL) OVERRIDE
{
tree ret = m_ranger->value_of_expr (name, s);
- if (!ret && is_pointer_ssa (name))
+ if (!ret && supported_pointer_equiv_p (name))
ret = m_pta->get_equiv (name);
return ret;
}
@@ -438,7 +146,7 @@ public:
tree value_on_edge (edge e, tree name) OVERRIDE
{
tree ret = m_ranger->value_on_edge (e, name);
- if (!ret && is_pointer_ssa (name))
+ if (!ret && supported_pointer_equiv_p (name))
ret = m_pta->get_equiv (name);
return ret;
}
@@ -570,7 +278,7 @@ hybrid_folder::value_of_expr (tree op, gimple *stmt)
{
tree evrp_ret = evrp_folder::value_of_expr (op, stmt);
tree ranger_ret = m_ranger->value_of_expr (op, stmt);
- if (!ranger_ret && is_pointer_ssa (op))
+ if (!ranger_ret && supported_pointer_equiv_p (op))
ranger_ret = m_pta->get_equiv (op);
return choose_value (evrp_ret, ranger_ret);
}
@@ -582,7 +290,7 @@ hybrid_folder::value_on_edge (edge e, tree op)
// via hybrid_folder::value_of_expr, but without an edge.
tree evrp_ret = evrp_folder::value_of_expr (op, NULL);
tree ranger_ret = m_ranger->value_on_edge (e, op);
- if (!ranger_ret && is_pointer_ssa (op))
+ if (!ranger_ret && supported_pointer_equiv_p (op))
ranger_ret = m_pta->get_equiv (op);
return choose_value (evrp_ret, ranger_ret);
}
new file mode 100644
@@ -0,0 +1,302 @@
+/* Context-aware pointer equivalence tracker.
+ Copyright (C) 2020-2021 Free Software Foundation, Inc.
+ Contributed by Aldy Hernandez <aldyh@redhat.com>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "backend.h"
+#include "tree.h"
+#include "gimple.h"
+#include "tree-pass.h"
+#include "ssa.h"
+#include "gimple-pretty-print.h"
+#include "cfganal.h"
+#include "gimple-fold.h"
+#include "tree-eh.h"
+#include "gimple-iterator.h"
+#include "tree-cfg.h"
+#include "tree-ssa-loop-manip.h"
+#include "tree-ssa-loop.h"
+#include "cfgloop.h"
+#include "tree-scalar-evolution.h"
+#include "tree-ssa-propagate.h"
+#include "alloc-pool.h"
+#include "domwalk.h"
+#include "tree-cfgcleanup.h"
+#include "vr-values.h"
+#include "gimple-ssa-evrp-analyze.h"
+#include "gimple-range.h"
+#include "fold-const.h"
+#include "value-pointer-equiv.h"
+
+// Unwindable SSA equivalence table for pointers.
+//
+// The main query point is get_replacement() which returns what a
+// given SSA can be replaced with in the current scope.
+
+class ssa_equiv_stack
+{
+public:
+ ssa_equiv_stack ();
+ void enter (basic_block);
+ void leave (basic_block);
+ void push_replacement (tree name, tree replacement);
+ tree get_replacement (tree name) const;
+
+private:
+ auto_vec<std::pair <tree, tree>> m_stack;
+ auto_vec<tree> m_replacements;
+ const std::pair <tree, tree> m_marker = std::make_pair (NULL, NULL);
+};
+
+ssa_equiv_stack::ssa_equiv_stack ()
+{
+ m_replacements.safe_grow_cleared (num_ssa_names);
+}
+
+// Pushes a marker at the given point.
+
+void
+ssa_equiv_stack::enter (basic_block)
+{
+ m_stack.safe_push (m_marker);
+}
+
+// Pops the stack to the last marker, while performing replacements
+// along the way.
+
+void
+ssa_equiv_stack::leave (basic_block)
+{
+ gcc_checking_assert (!m_stack.is_empty ());
+ while (m_stack.last () != m_marker)
+ {
+ std::pair<tree, tree> e = m_stack.pop ();
+ m_replacements[SSA_NAME_VERSION (e.first)] = e.second;
+ }
+ m_stack.pop ();
+}
+
+// Set the equivalence of NAME to REPLACEMENT.
+
+void
+ssa_equiv_stack::push_replacement (tree name, tree replacement)
+{
+ tree old = m_replacements[SSA_NAME_VERSION (name)];
+ m_replacements[SSA_NAME_VERSION (name)] = replacement;
+ m_stack.safe_push (std::make_pair (name, old));
+}
+
+// Return the equivalence of NAME.
+
+tree
+ssa_equiv_stack::get_replacement (tree name) const
+{
+ return m_replacements[SSA_NAME_VERSION (name)];
+}
+
+pointer_equiv_analyzer::pointer_equiv_analyzer (gimple_ranger *r)
+{
+ m_ranger = r;
+ m_global_points = new tree[num_ssa_names] ();
+ m_cond_points = new ssa_equiv_stack;
+}
+
+pointer_equiv_analyzer::~pointer_equiv_analyzer ()
+{
+ delete[] m_global_points;
+ delete m_cond_points;
+}
+
+// Set the global pointer equivalency for SSA to POINTEE.
+
+void
+pointer_equiv_analyzer::set_global_equiv (tree ssa, tree pointee)
+{
+ m_global_points[SSA_NAME_VERSION (ssa)] = pointee;
+}
+
+// Set the conditional pointer equivalency for SSA to POINTEE.
+
+void
+pointer_equiv_analyzer::set_cond_equiv (tree ssa, tree pointee)
+{
+ m_cond_points->push_replacement (ssa, pointee);
+}
+
+// Return the current pointer equivalency info for SSA, or NULL if
+// none is available. Note that global info takes priority over
+// conditional info.
+
+tree
+pointer_equiv_analyzer::get_equiv (tree ssa) const
+{
+ tree ret = m_global_points[SSA_NAME_VERSION (ssa)];
+ if (ret)
+ return ret;
+ return m_cond_points->get_replacement (ssa);
+}
+
+// Method to be called on entry to a BB.
+
+void
+pointer_equiv_analyzer::enter (basic_block bb)
+{
+ m_cond_points->enter (bb);
+
+ for (gphi_iterator iter = gsi_start_phis (bb);
+ !gsi_end_p (iter);
+ gsi_next (&iter))
+ {
+ gphi *phi = iter.phi ();
+ tree lhs = gimple_phi_result (phi);
+ if (!POINTER_TYPE_P (TREE_TYPE (lhs)))
+ continue;
+ tree arg0 = gimple_phi_arg_def (phi, 0);
+ if (TREE_CODE (arg0) == SSA_NAME && !is_gimple_min_invariant (arg0))
+ arg0 = get_equiv (arg0);
+ if (arg0 && is_gimple_min_invariant (arg0))
+ {
+ // If all the PHI args point to the same place, set the
+ // pointer equivalency info for the PHI result. This can
+ // happen for passes that create redundant PHIs like
+ // PHI<&foo, &foo> or PHI<&foo>.
+ for (size_t i = 1; i < gimple_phi_num_args (phi); ++i)
+ {
+ tree argi = gimple_phi_arg_def (phi, i);
+ if (TREE_CODE (argi) == SSA_NAME
+ && !is_gimple_min_invariant (argi))
+ argi = get_equiv (argi);
+ if (!argi || !operand_equal_p (arg0, argi))
+ return;
+ }
+ set_global_equiv (lhs, arg0);
+ }
+ }
+
+ edge pred = single_pred_edge_ignoring_loop_edges (bb, false);
+ if (pred)
+ visit_edge (pred);
+}
+
+// Method to be called on exit from a BB.
+
+void
+pointer_equiv_analyzer::leave (basic_block bb)
+{
+ m_cond_points->leave (bb);
+}
+
+// Helper function to return the pointer equivalency information for
+// EXPR from a gimple statement with CODE. This returns either the
+// cached pointer equivalency info for an SSA, or an invariant in case
+// EXPR is one (i.e. &foo). Returns NULL if EXPR is neither an SSA
+// nor an invariant.
+
+tree
+pointer_equiv_analyzer::get_equiv_expr (tree_code code, tree expr) const
+{
+ if (code == SSA_NAME)
+ return get_equiv (expr);
+
+ if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS
+ && is_gimple_min_invariant (expr))
+ return expr;
+
+ return NULL;
+}
+
+// Hack to provide context to the gimple fold callback.
+static struct
+{
+ gimple *m_stmt;
+ gimple_ranger *m_ranger;
+ pointer_equiv_analyzer *m_pta;
+} x_fold_context;
+
+// Gimple fold callback.
+static tree
+pta_valueize (tree name)
+{
+ tree ret
+ = x_fold_context.m_ranger->value_of_expr (name, x_fold_context.m_stmt);
+
+ if (!ret && supported_pointer_equiv_p (name))
+ ret = x_fold_context.m_pta->get_equiv (name);
+
+ return ret ? ret : name;
+}
+
+// Method to be called on gimple statements during traversal of the IL.
+
+void
+pointer_equiv_analyzer::visit_stmt (gimple *stmt)
+{
+ if (gimple_code (stmt) != GIMPLE_ASSIGN)
+ return;
+
+ tree lhs = gimple_assign_lhs (stmt);
+ if (!supported_pointer_equiv_p (lhs))
+ return;
+
+ tree rhs = gimple_assign_rhs1 (stmt);
+ rhs = get_equiv_expr (gimple_assign_rhs_code (stmt), rhs);
+ if (rhs)
+ {
+ set_global_equiv (lhs, rhs);
+ return;
+ }
+
+ // If we couldn't find anything, try fold.
+ x_fold_context = { stmt, m_ranger, this};
+ rhs = gimple_fold_stmt_to_constant_1 (stmt, pta_valueize, pta_valueize);
+ if (rhs)
+ {
+ rhs = get_equiv_expr (TREE_CODE (rhs), rhs);
+ if (rhs)
+ {
+ set_global_equiv (lhs, rhs);
+ return;
+ }
+ }
+}
+
+// If the edge in E is a conditional that sets a pointer equality, set the
+// conditional pointer equivalency information.
+
+void
+pointer_equiv_analyzer::visit_edge (edge e)
+{
+ gimple *stmt = last_stmt (e->src);
+ tree lhs;
+ // Recognize: x_13 [==,!=] &foo.
+ if (stmt
+ && gimple_code (stmt) == GIMPLE_COND
+ && (lhs = gimple_cond_lhs (stmt))
+ && TREE_CODE (lhs) == SSA_NAME
+ && POINTER_TYPE_P (TREE_TYPE (lhs))
+ && TREE_CODE (gimple_cond_rhs (stmt)) == ADDR_EXPR)
+ {
+ tree_code code = gimple_cond_code (stmt);
+ if ((code == EQ_EXPR && e->flags & EDGE_TRUE_VALUE)
+ || ((code == NE_EXPR && e->flags & EDGE_FALSE_VALUE)))
+ set_cond_equiv (lhs, gimple_cond_rhs (stmt));
+ }
+}
new file mode 100644
@@ -0,0 +1,62 @@
+/* Header file for the context-aware pointer equivalence tracker.
+ Copyright (C) 2020-2021 Free Software Foundation, Inc.
+ Contributed by Aldy Hernandez <aldyh@redhat.com>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#ifndef GCC_VALUE_POINTER_EQUIV_H
+#define GCC_VALUE_POINTER_EQUIV_H
+
+// Simple context-aware pointer equivalency analyzer that returns what
+// a pointer SSA name is equivalent to at a given point during a walk
+// of the IL.
+//
+// Note that global equivalency take priority over conditional
+// equivalency. That is, p = &q takes priority over a later p == &t.
+//
+// This class is meant to be called during a DOM walk.
+
+class pointer_equiv_analyzer
+{
+public:
+ pointer_equiv_analyzer (gimple_ranger *r);
+ ~pointer_equiv_analyzer ();
+ void enter (basic_block);
+ void leave (basic_block);
+ void visit_stmt (gimple *stmt);
+ tree get_equiv (tree ssa) const;
+
+private:
+ void visit_edge (edge e);
+ tree get_equiv_expr (tree_code code, tree expr) const;
+ void set_global_equiv (tree ssa, tree pointee);
+ void set_cond_equiv (tree ssa, tree pointee);
+
+ gimple_ranger *m_ranger;
+ // Global pointer equivalency indexed by SSA_NAME_VERSION.
+ tree *m_global_points;
+ // Conditional pointer equivalency.
+ class ssa_equiv_stack *m_cond_points;
+};
+
+inline bool
+supported_pointer_equiv_p (tree expr)
+{
+ return TREE_CODE (expr) == SSA_NAME && POINTER_TYPE_P (TREE_TYPE (expr));
+}
+
+#endif // GCC_VALUE_POINTER_EQUIV_H