machmode.h (bit_field_mode_iterator): New class.

gcc/
	* machmode.h (bit_field_mode_iterator): New class.
	(get_best_mode): Change final parameter to bool.
	* stor-layout.c (bit_field_mode_iterator::bit_field_mode_iterator)
	(bit_field_mode_iterator::next_mode): New functions, split out from...
	(get_best_mode): ...here.  Change final parameter to bool.
	Use bit_field_mode_iterator.

From-SVN: r193603

1 files changed, 24 insertions, 1 deletions

diff --git a/gcc/machmode.h b/gcc/machmode.h
index b95d05b096e..f1c89cc8a63 100644
--- a/gcc/machmode.h
+++ b/gcc/machmode.h
@@ -259,13 +259,36 @@ extern enum machine_mode int_mode_for_mode (enum machine_mode);
 
 extern enum machine_mode mode_for_vector (enum machine_mode, unsigned);
 
+/* A class for iterating through possible bitfield modes.  */
+class bit_field_mode_iterator
+{
+public:
+  bit_field_mode_iterator (HOST_WIDE_INT, HOST_WIDE_INT,
+			   HOST_WIDE_INT, HOST_WIDE_INT,
+			   unsigned int, bool);
+  bool next_mode (enum machine_mode *);
+  bool prefer_smaller_modes ();
+
+private:
+  enum machine_mode mode_;
+  /* We use signed values here because the bit position can be negative
+     for invalid input such as gcc.dg/pr48335-8.c.  */
+  HOST_WIDE_INT bitsize_;
+  HOST_WIDE_INT bitpos_;
+  HOST_WIDE_INT bitregion_start_;
+  HOST_WIDE_INT bitregion_end_;
+  unsigned int align_;
+  bool volatilep_;
+  int count_;
+};
+
 /* Find the best mode to use to access a bit field.  */
 
 extern enum machine_mode get_best_mode (int, int,
 					unsigned HOST_WIDE_INT,
 					unsigned HOST_WIDE_INT,
 					unsigned int,
-					enum machine_mode, int);
+					enum machine_mode, bool);
 
 /* Determine alignment, 1<=result<=BIGGEST_ALIGNMENT.  */