Add gimple_range_type for statements.

The existing mechanisms for picking up the type of a statement are
inconsistent with the needs of ranger. Encapsulate all the bits
required to pick up the return type of a statement in one place, and check
whether the type is supported.

	* gimple-range-fold.cc (adjust_pointer_diff_expr): Use
	gimple_range_type.
	(fold_using_range::fold_stmt): Ditto.
	(fold_using_range::range_of_range_op): Ditto.
	(fold_using_range::range_of_phi): Ditto.
	(fold_using_range::range_of_call): Ditto.
	(fold_using_range::range_of_builtin_ubsan_call): Ditto.
	(fold_using_range::range_of_builtin_call): Ditto.
	(fold_using_range::range_of_cond_expr): Ditto.
	* gimple-range-fold.h (gimple_range_type): New.

2 files changed, 49 insertions, 25 deletions

diff --git a/gcc/gimple-range-fold.cc b/gcc/gimple-range-fold.cc
index eff5d1f..f8578c0 100644
--- a/gcc/gimple-range-fold.cc
+++ b/gcc/gimple-range-fold.cc
@@ -362,7 +362,7 @@ adjust_pointer_diff_expr (irange &res, const gimple *diff_stmt)
     {
       tree max = vrp_val_max (ptrdiff_type_node);
       wide_int wmax = wi::to_wide (max, TYPE_PRECISION (TREE_TYPE (max)));
-      tree expr_type = gimple_expr_type (diff_stmt);
+      tree expr_type = gimple_range_type (diff_stmt);
       tree range_min = build_zero_cst (expr_type);
       tree range_max = wide_int_to_tree (expr_type, wmax - 1);
       int_range<2> r (range_min, range_max);
@@ -522,16 +522,8 @@ fold_using_range::fold_stmt (irange &r, gimple *s, fur_source &src, tree name)
 
   if (!res)
     {
-      // If no name is specified, try the expression kind.
-      if (!name)
-	{
-	  tree t = gimple_expr_type (s);
-	  if (!irange::supports_type_p (t))
-	    return false;
-	  r.set_varying (t);
-	  return true;
-	}
-      if (!gimple_range_ssa_p (name))
+      // If no name specified or range is unsupported, bail.
+      if (!name || !gimple_range_ssa_p (name))
 	return false;
       // We don't understand the stmt, so return the global range.
       r = gimple_range_global (name);
@@ -558,10 +550,11 @@ bool
 fold_using_range::range_of_range_op (irange &r, gimple *s, fur_source &src)
 {
   int_range_max range1, range2;
-  tree type = gimple_expr_type (s);
+  tree type = gimple_range_type (s);
+  if (!type)
+    return false;
   range_operator *handler = gimple_range_handler (s);
   gcc_checking_assert (handler);
-  gcc_checking_assert (irange::supports_type_p (type));
 
   tree lhs = gimple_get_lhs (s);
   tree op1 = gimple_range_operand1 (s);
@@ -719,11 +712,11 @@ bool
 fold_using_range::range_of_phi (irange &r, gphi *phi, fur_source &src)
 {
   tree phi_def = gimple_phi_result (phi);
-  tree type = TREE_TYPE (phi_def);
+  tree type = gimple_range_type (phi);
   int_range_max arg_range;
   unsigned x;
 
-  if (!irange::supports_type_p (type))
+  if (!type)
     return false;
 
   // Start with an empty range, unioning in each argument's range.
@@ -780,13 +773,13 @@ fold_using_range::range_of_phi (irange &r, gphi *phi, fur_source &src)
 bool
 fold_using_range::range_of_call (irange &r, gcall *call, fur_source &src)
 {
-  tree type = gimple_call_return_type (call);
+  tree type = gimple_range_type (call);
+  if (!type)
+    return false;
+
   tree lhs = gimple_call_lhs (call);
   bool strict_overflow_p;
 
-  if (!irange::supports_type_p (type))
-    return false;
-
   if (range_of_builtin_call (r, call, src))
     ;
   else if (gimple_stmt_nonnegative_warnv_p (call, &strict_overflow_p))
@@ -817,7 +810,7 @@ fold_using_range::range_of_builtin_ubsan_call (irange &r, gcall *call,
 {
   gcc_checking_assert (code == PLUS_EXPR || code == MINUS_EXPR
 		       || code == MULT_EXPR);
-  tree type = gimple_call_return_type (call);
+  tree type = gimple_range_type (call);
   range_operator *op = range_op_handler (code, type);
   gcc_checking_assert (op);
   int_range_max ir0, ir1;
@@ -853,7 +846,7 @@ fold_using_range::range_of_builtin_call (irange &r, gcall *call,
   if (func == CFN_LAST)
     return false;
 
-  tree type = gimple_call_return_type (call);
+  tree type = gimple_range_type (call);
   tree arg;
   int mini, maxi, zerov = 0, prec;
   scalar_int_mode mode;
@@ -1094,12 +1087,12 @@ fold_using_range::range_of_cond_expr  (irange &r, gassign *s, fur_source &src)
   tree op1 = gimple_assign_rhs2 (s);
   tree op2 = gimple_assign_rhs3 (s);
 
-  gcc_checking_assert (gimple_assign_rhs_code (s) == COND_EXPR);
-  gcc_checking_assert (useless_type_conversion_p  (TREE_TYPE (op1),
-						   TREE_TYPE (op2)));
-  if (!irange::supports_type_p (TREE_TYPE (op1)))
+  tree type = gimple_range_type (s);
+  if (!type)
     return false;
 
+  gcc_checking_assert (gimple_assign_rhs_code (s) == COND_EXPR);
+  gcc_checking_assert (range_compatible_p (TREE_TYPE (op1), TREE_TYPE (op2)));
   src.get_operand (cond_range, cond);
   src.get_operand (range1, op1);
   src.get_operand (range2, op2);
@@ -1118,6 +1111,7 @@ fold_using_range::range_of_cond_expr  (irange &r, gassign *s, fur_source &src)
       r = range1;
       r.union_ (range2);
     }
+  gcc_checking_assert (range_compatible_p (r.type (), type));
   return true;
 }
 
diff --git a/gcc/gimple-range-fold.h b/gcc/gimple-range-fold.h
index dc1b28f..ceed7ba 100644
--- a/gcc/gimple-range-fold.h
+++ b/gcc/gimple-range-fold.h
@@ -56,6 +56,36 @@ gimple_range_handler (const gimple *s)
   return NULL;
 }
 
+// Return the type of range which statement S calculates.  If the type is
+// unsupported or no type can be determined, return NULL_TREE.
+
+static inline tree
+gimple_range_type (const gimple *s)
+{
+  tree lhs = gimple_get_lhs (s);
+  tree type = NULL_TREE;
+  if (lhs)
+    type = TREE_TYPE (lhs);
+  else
+    {
+      enum gimple_code code = gimple_code (s);
+      if (code == GIMPLE_COND)
+	type = boolean_type_node;
+      else if (code == GIMPLE_PHI)
+	type = TREE_TYPE (gimple_phi_result (s));
+      else if (code == GIMPLE_CALL)
+	{
+	  type = gimple_call_fntype (s);
+	  // If it has a type, get the return type.
+	  if (type)
+	    type = TREE_TYPE (type);
+	}
+    }
+  if (irange::supports_type_p (type))
+    return type;
+  return NULL_TREE;
+}
+
 // Return EXP if it is an SSA_NAME with a type supported by gimple ranges.
 
 static inline tree