c-convert.c (convert): When converting to a BOOLEAN_TYPE, avoid passing nested NOP_EXPRs to fold.

	* c-convert.c (convert): When converting to a BOOLEAN_TYPE, avoid
	passing nested NOP_EXPRs to fold.

testsuite:
	* gcc.c-torture/compile/20010423-1.c: New test.

From-SVN: r41508

gcc/ChangeLog

+2001-04-23  Joseph S. Myers  <jsm28@cam.ac.uk>
+
+	* c-convert.c (convert): When converting to a BOOLEAN_TYPE, avoid
+	passing nested NOP_EXPRs to fold.
+
 Mon Apr 23 14:32:12 CEST 2001  Jan Hubicka  <jh@suse.cz>
 
 	* reg-stack.c (emit_swap_insn): Do not get pass CALL_INSNs.

gcc/c-convert.c

@@ -89,7 +89,15 @@ convert (type, expr)
   if (code == INTEGER_TYPE || code == ENUMERAL_TYPE)
     return fold (convert_to_integer (type, e));
   if (code == BOOLEAN_TYPE)
-    return fold (build1 (NOP_EXPR, type, truthvalue_conversion (expr)));
+    {
+      tree t = truthvalue_conversion (expr);
+      /* If truthvalue_conversion returns a NOP_EXPR, we must fold it here
+	 to avoid infinite recursion between fold () and convert ().  */
+      if (TREE_CODE (t) == NOP_EXPR)
+	return fold (build1 (NOP_EXPR, type, TREE_OPERAND (t, 0)));
+      else
+	return fold (build1 (NOP_EXPR, type, t));
+    }
   if (code == POINTER_TYPE || code == REFERENCE_TYPE)
     return fold (convert_to_pointer (type, e));
   if (code == REAL_TYPE)

gcc/testsuite/ChangeLog

+2001-04-23  Joseph S. Myers  <jsm28@cam.ac.uk>
+
+	* gcc.c-torture/compile/20010423-1.c: New test.
+
 2001-04-20  Nathan Sidwell  <nathan@codesourcery.com>
 
 	* g++.old-deja/g++.pt/typename28.C: New test.

gcc/testsuite/gcc.c-torture/compile/20010423-1.c

+/* Origin: PR c/2618 from Cesar Eduardo Barros <cesarb@nitnet.com.br>,
+   adapted to a testcase by Joseph Myers <jsm28@cam.ac.uk>.
+
+   Boolean conversions were causing infinite recursion between convert
+   and fold in certain cases.  */
+
+#include <stdbool.h>
+
+bool x;
+unsigned char y;
+
+void
+fn (void)
+{
+  x = y & 0x1 ? 1 : 0;
+}