utils.c (max_size): Flip the second argument when recursing on TRUTH_NOT_EXPR.

	* gcc-interface/utils.c (max_size) <tcc_expression>: Flip the second
	argument when recursing on TRUTH_NOT_EXPR.

From-SVN: r245697

gcc/ada/ChangeLog

+2017-02-24  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc-interface/utils.c (max_size) <tcc_expression>: Flip the second
+	argument when recursing on TRUTH_NOT_EXPR.
+
 2017-02-12  John Marino  <gnugcc@marino.st>
 
 	* system-freebsd-x86.ads: Rename into...

gcc/ada/gcc-interface/utils.c

@@ -3635,7 +3635,8 @@ max_size (tree exp, bool max_p)
 	    return exp;
 
 	  return fold_build1 (code, type,
-			      max_size (TREE_OPERAND (exp, 0), max_p));
+			      max_size (TREE_OPERAND (exp, 0),
+			      code == TRUTH_NOT_EXPR ? !max_p : max_p));
 
 	case 2:
 	  if (code == COMPOUND_EXPR)

gcc/testsuite/ChangeLog

+2017-02-24  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat.dg/discr47.adb: New test.
+
 2017-02-24  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/79389

gcc/testsuite/gnat.dg/discr47.adb

+-- { dg-do run }
+-- { dg-options "-O -gnatws" }
+
+procedure Discr47 is
+
+  type Rec (D : Boolean := False) is record
+    case D is
+      when True => null;
+      when False => C : Character;
+    end case;
+  end record;
+
+  R : Rec;
+
+begin
+  if R'Size /= 16 then
+    raise Program_Error;
+  end if;
+end;