[gcc r12-1190] Implement generic expression evaluator for range_query.

[gcc r12-1190] Implement generic expression evaluator for range_query.

[Aldy Hernandez]

https://gcc.gnu.org/g:caa60c12715dd9b0cbb550a45e5878214a10a2fe

commit r12-1190-gcaa60c12715dd9b0cbb550a45e5878214a10a2fe
Author: Aldy Hernandez <aldyh@redhat.com>
Date:   Wed May 26 08:40:17 2021 +0200

    Implement generic expression evaluator for range_query.
    
    Right now, range_of_expr only works with constants, SSA names, and
    pointers.  Anything else gets returned as VARYING.  This patch adds the
    capability to deal with arbitrary expressions, inasmuch as these
    tree codes are implemented in range-ops.cc.
    
    This will give us the ability to ask for the range of any tree expression,
    not just constants and SSA names, with range_of_expr().
    
    This is a more generic implementation of determine_value_range in VRP.
    A follow-up patch will remove all uses of it in favor of the
    range_query API.
    
    gcc/ChangeLog:
    
            * function-tests.c (test_ranges): Call gimple_range_tests.
            * gimple-range-cache.cc (ranger_cache::range_of_expr): Pass stmt
            to get_tree_range.
            * gimple-range.cc (fur_source::get_operand): Do not call
            get_tree_range or gimple_range_global.
            get_tree_range.
            (get_tree_range): Move to value-query.cc.
            Call get_arith_expr_range.
            (gimple_ranger::range_of_expr): Add argument to get_tree_range.
            Include gimple-range-tests.cc.
            * gimple-range.h (fold_range): Add argument.
            (get_tree_range): Remove.
            * selftest.h (gimple_range_tests): New.
            * value-query.cc (global_range_query::range_of_expr): Add
            stmt argument.
            (range_query::get_tree_range): Move from gimple-range.cc.
            * value-query.h (class range_query): Add get_tree_range and
            get_arith_expr_range.  Make fur_source a friend.
            * vr-values.c (vr_values::range_of_expr): Pass stmt to
            get_tree_range.
            * gimple-range-tests.cc: New file.

Diff:
---
 gcc/function-tests.c      |  5 +++
 gcc/gimple-range-cache.cc |  4 +--
 gcc/gimple-range-tests.cc | 72 ++++++++++++++++++++++++++++++++++++++++
 gcc/gimple-range.cc       | 64 ++----------------------------------
 gcc/gimple-range.h        |  7 ++--
 gcc/selftest.h            |  1 +
 gcc/value-query.cc        | 84 +++++++++++++++++++++++++++++++++++++++++++++--
 gcc/value-query.h         |  2 ++
 gcc/vr-values.c           |  2 +-
 9 files changed, 172 insertions(+), 69 deletions(-)

diff --git a/gcc/function-tests.c b/gcc/function-tests.c
index 1b8f665cde1..0ac1d37f8ff 100644
--- a/gcc/function-tests.c
+++ b/gcc/function-tests.c
@@ -581,6 +581,11 @@ test_ranges ()
   push_cfun (fun);
   range_tests ();
   range_op_tests ();
+
+  build_cfg (fndecl);
+  convert_to_ssa (fndecl);
+  gimple_range_tests ();
+
   pop_cfun ();
 }
 
diff --git a/gcc/gimple-range-cache.cc b/gcc/gimple-range-cache.cc
index cc27574b7b4..c58acf48dfb 100644
--- a/gcc/gimple-range-cache.cc
+++ b/gcc/gimple-range-cache.cc
@@ -827,7 +827,7 @@ ranger_cache::range_of_expr (irange &r, tree name, gimple *stmt)
 {
   if (!gimple_range_ssa_p (name))
     {
-      get_tree_range (r, name);
+      get_tree_range (r, name, stmt);
       return true;
     }
 
@@ -860,7 +860,7 @@ ranger_cache::range_of_expr (irange &r, tree name, gimple *stmt)
 	}
     }
   else
-    get_tree_range (r, expr);
+    get_tree_range (r, expr, NULL);
   return false;
 }
 
diff --git a/gcc/gimple-range-tests.cc b/gcc/gimple-range-tests.cc
new file mode 100644
index 00000000000..9ee4c5aa6cd
--- /dev/null
+++ b/gcc/gimple-range-tests.cc
@@ -0,0 +1,72 @@
+/* Unit tests for GIMPLE range related routines.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+
+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/>.  */
+
+#if CHECKING_P
+
+#include "selftest.h"
+
+namespace selftest {
+
+// Test ranges of tree expressions.
+class test_expr_eval : public gimple_ranger
+{
+public:
+  test_expr_eval ()
+  {
+    type = integer_type_node;
+    op0 = make_ssa_name (type);
+    op1 = make_ssa_name (type);
+
+    // [5,10] + [15,20] => [20, 30]
+    tree expr = fold_build2 (PLUS_EXPR, type, op0, op1);
+    int_range<2> expect (build_int_cst (type, 20), build_int_cst (type, 30));
+    int_range_max r;
+
+    ASSERT_TRUE (range_of_expr (r, expr));
+    ASSERT_TRUE (r == expect);
+  }
+
+  virtual bool range_of_expr (irange &r, tree expr, gimple * = NULL) OVERRIDE
+  {
+    if (expr == op0)
+      {
+	r.set (build_int_cst (type, 5), build_int_cst (type, 10));
+	return true;
+      }
+    if (expr == op1)
+      {
+	r.set (build_int_cst (type, 15), build_int_cst (type, 20));
+	return true;
+      }
+    return gimple_ranger::range_of_expr (r, expr);
+  }
+
+private:
+  tree op0, op1, type;
+};
+
+void
+gimple_range_tests ()
+{
+  test_expr_eval e;
+}
+
+} // namespace selftest
+
+#endif // CHECKING_P
diff --git a/gcc/gimple-range.cc b/gcc/gimple-range.cc
index af426207092..db8419bc4c6 100644
--- a/gcc/gimple-range.cc
+++ b/gcc/gimple-range.cc
@@ -54,16 +54,6 @@ along with GCC; see the file COPYING3.  If not see
 bool
 fur_source::get_operand (irange &r, tree expr)
 {
-  if (!gimple_range_ssa_p (expr))
-    return get_tree_range (r, expr);
-
-  // If no query engine is present, simply get the global value.
-  if (!m_query)
-    {
-       r = gimple_range_global (expr);
-       return true;
-    }
-
   // First look for a stmt.
   if (m_stmt)
     return m_query->range_of_expr (r, expr, m_stmt);
@@ -168,56 +158,6 @@ gimple_range_adjustment (irange &res, const gimple *stmt)
     }
 }
 
-// Return a range in R for the tree EXPR.  Return true if a range is
-// representable, and UNDEFINED/false if not.
-
-bool
-get_tree_range (irange &r, tree expr)
-{
-  tree type;
-  if (TYPE_P (expr))
-    type = expr;
-  else
-    type = TREE_TYPE (expr);
-
-  // Return false if the type isn't suported.
-  if (!irange::supports_type_p (type))
-    {
-      r.set_undefined ();
-      return false;
-    }
-
-  switch (TREE_CODE (expr))
-    {
-      case INTEGER_CST:
-	if (TREE_OVERFLOW_P (expr))
-	  expr = drop_tree_overflow (expr);
-	r.set (expr, expr);
-	return true;
-
-      case SSA_NAME:
-	r = gimple_range_global (expr);
-	return true;
-
-      case ADDR_EXPR:
-        {
-	  // Handle &var which can show up in phi arguments.
-	  bool ov;
-	  if (tree_single_nonzero_warnv_p (expr, &ov))
-	    {
-	      r = range_nonzero (type);
-	      return true;
-	    }
-	  break;
-	}
-
-      default:
-        break;
-    }
-  r.set_varying (type);
-  return true;
-}
-
 // Return the base of the RHS of an assignment.
 
 static tree
@@ -961,7 +901,7 @@ bool
 gimple_ranger::range_of_expr (irange &r, tree expr, gimple *stmt)
 {
   if (!gimple_range_ssa_p (expr))
-    return get_tree_range (r, expr);
+    return get_tree_range (r, expr, stmt);
 
   // If there is no statement, just get the global value.
   if (!stmt)
@@ -1466,3 +1406,5 @@ disable_ranger (struct function *fun)
 
   fun->x_range_query = &global_ranges;
 }
+
+#include "gimple-range-tests.cc"
diff --git a/gcc/gimple-range.h b/gcc/gimple-range.h
index 65f62e4ba9b..02b891fad69 100644
--- a/gcc/gimple-range.h
+++ b/gcc/gimple-range.h
@@ -159,6 +159,8 @@ inline bool
 fold_range (irange &r, gimple *s, range_query *q = NULL)
 {
   fold_using_range f;
+  if (q == NULL)
+    q = get_global_range_query ();
   fur_source src (q, s);
   return f.fold_stmt (r, s, src);
 }
@@ -169,13 +171,12 @@ inline bool
 fold_range (irange &r, gimple *s, edge on_edge, range_query *q = NULL)
 {
   fold_using_range f;
+  if (q == NULL)
+    q = get_global_range_query ();
   fur_source src (q, on_edge);
   return f.fold_stmt (r, s, src);
 }
 
-// Calculate a basic range for a tree node expression.
-extern bool get_tree_range (irange &r, tree expr);
-
 // These routines provide a GIMPLE interface to the range-ops code.
 extern tree gimple_range_operand1 (const gimple *s);
 extern tree gimple_range_operand2 (const gimple *s);
diff --git a/gcc/selftest.h b/gcc/selftest.h
index e609117ec2b..80459d63a39 100644
--- a/gcc/selftest.h
+++ b/gcc/selftest.h
@@ -249,6 +249,7 @@ extern void predict_c_tests ();
 extern void pretty_print_c_tests ();
 extern void range_tests ();
 extern void range_op_tests ();
+extern void gimple_range_tests ();
 extern void read_rtl_function_c_tests ();
 extern void rtl_tests_c_tests ();
 extern void sbitmap_c_tests ();
diff --git a/gcc/value-query.cc b/gcc/value-query.cc
index 070d706166e..821f224d4ab 100644
--- a/gcc/value-query.cc
+++ b/gcc/value-query.cc
@@ -182,6 +182,86 @@ range_query::~range_query ()
   delete equiv_alloc;
 }
 
+// Return a range in R for the tree EXPR.  Return true if a range is
+// representable, and UNDEFINED/false if not.
+
+bool
+range_query::get_tree_range (irange &r, tree expr, gimple *stmt)
+{
+  tree type;
+  if (TYPE_P (expr))
+    type = expr;
+  else
+    type = TREE_TYPE (expr);
+
+  if (!irange::supports_type_p (type))
+    {
+      r.set_undefined ();
+      return false;
+    }
+  if (expr == type)
+    {
+      r.set_varying (type);
+      return true;
+    }
+  switch (TREE_CODE (expr))
+    {
+    case INTEGER_CST:
+      if (TREE_OVERFLOW_P (expr))
+	expr = drop_tree_overflow (expr);
+      r.set (expr, expr);
+      return true;
+
+    case SSA_NAME:
+      r = gimple_range_global (expr);
+      return true;
+
+    case ADDR_EXPR:
+      {
+	// Handle &var which can show up in phi arguments.
+	bool ov;
+	if (tree_single_nonzero_warnv_p (expr, &ov))
+	  {
+	    r = range_nonzero (type);
+	    return true;
+	  }
+	break;
+      }
+
+    default:
+      break;
+    }
+  if (BINARY_CLASS_P (expr))
+    {
+      range_operator *op = range_op_handler (TREE_CODE (expr), type);
+      if (op)
+	{
+	  int_range_max r0, r1;
+	  range_of_expr (r0, TREE_OPERAND (expr, 0), stmt);
+	  range_of_expr (r1, TREE_OPERAND (expr, 1), stmt);
+	  op->fold_range (r, type, r0, r1);
+	}
+      else
+	r.set_varying (type);
+      return true;
+    }
+  if (UNARY_CLASS_P (expr))
+    {
+      range_operator *op = range_op_handler (TREE_CODE (expr), type);
+      if (op)
+	{
+	  int_range_max r0;
+	  range_of_expr (r0, TREE_OPERAND (expr, 0), stmt);
+	  op->fold_range (r, type, r0, int_range<1> (type));
+	}
+      else
+	r.set_varying (type);
+      return true;
+    }
+  r.set_varying (type);
+  return true;
+}
+
 // Return the range for NAME from SSA_NAME_RANGE_INFO.
 
 static inline void
@@ -355,12 +435,12 @@ get_global_range_query ()
 }
 
 bool
-global_range_query::range_of_expr (irange &r, tree expr, gimple *)
+global_range_query::range_of_expr (irange &r, tree expr, gimple *stmt)
 {
   tree type = TREE_TYPE (expr);
 
   if (!irange::supports_type_p (type) || !gimple_range_ssa_p (expr))
-    return get_tree_range (r, expr);
+    return get_tree_range (r, expr, stmt);
 
   get_range_global (r, expr);
 
diff --git a/gcc/value-query.h b/gcc/value-query.h
index d0512e40c5a..77e49e9a906 100644
--- a/gcc/value-query.h
+++ b/gcc/value-query.h
@@ -100,6 +100,8 @@ public:
 protected:
   class value_range_equiv *allocate_value_range_equiv ();
   void free_value_range_equiv (class value_range_equiv *);
+  bool get_tree_range (irange &r, tree expr, gimple *stmt);
+  bool get_arith_expr_range (irange &r, tree expr, gimple *stmt);
 
 private:
   class equiv_allocator *equiv_alloc;
diff --git a/gcc/vr-values.c b/gcc/vr-values.c
index 3d0be8edb3b..509c8b093c5 100644
--- a/gcc/vr-values.c
+++ b/gcc/vr-values.c
@@ -180,7 +180,7 @@ bool
 vr_values::range_of_expr (irange &r, tree expr, gimple *stmt)
 {
   if (!gimple_range_ssa_p (expr))
-    return get_tree_range (r, expr);
+    return get_tree_range (r, expr, stmt);
 
   if (const value_range *vr = get_value_range (expr, stmt))
     {