[Patch 3/7 arc] Deprecate *_BY_PIECES_P, move to hookized version

[James Greenhalgh <james dot greenhalgh at arm dot com>]

Hi,

This patch moves arc to TARGET_USE_BY_PIECES_INFRASTRUCTURE_P.

While I am there, arc defines a macro CAN_MOVE_BY_PIECES, which is
unused, so clean that up too.

arc only implements MOVE_BY_PIECES_P, wiring it to false. Mirror that
behaviour, and use the default hook for other by_pieces operations.

I tried building a compiler but no amount of fiddling with target
strings got me to a sensible result, so this patch is completely
untested.

If one of the arc maintainers could give it a spin that would be
helpful.

OK?

Thanks,
James

 ---
2014-10-31  James Greenhalgh  <james.greenhalgh@arm.com>

	* config/arc/arc.c (TARGET_USE_BY_PIECES_INFRASTRUCTURE_P): New.
	(arc_use_by_pieces_infrastructure_p): Likewise.
	* confir/arc/arc.h (MOVE_BY_PIECES_P): Delete.
	(CAN_MOVE_BY_PIECES): Likewise.

diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c
index d04be01..c5b8b80 100644
--- a/gcc/config/arc/arc.c
+++ b/gcc/config/arc/arc.c
@@ -415,6 +415,11 @@ static void output_short_suffix (FILE *file);
 
 static bool arc_frame_pointer_required (void);
 
+static bool arc_use_by_pieces_infrastructure_p (unsigned int,
+						unsigned int,
+						enum by_pieces_operation op,
+						bool);
+
 /* Implements target hook vector_mode_supported_p.  */
 
 static bool
@@ -530,6 +535,10 @@ static void arc_finalize_pic (void);
 #undef TARGET_DELEGITIMIZE_ADDRESS
 #define TARGET_DELEGITIMIZE_ADDRESS arc_delegitimize_address
 
+#undef TARGET_USE_BY_PIECES_INFRASTRUCTURE_P
+#define TARGET_USE_BY_PIECES_INFRASTRUCTURE_P \
+  arc_use_by_pieces_infrastructure_p
+
 /* Usually, we will be able to scale anchor offsets.
    When this fails, we want LEGITIMIZE_ADDRESS to kick in.  */
 #undef TARGET_MIN_ANCHOR_OFFSET
@@ -9383,6 +9392,21 @@ arc_legitimize_reload_address (rtx *p, machine_mode mode, int opnum,
   return false;
 }
 
+/* Implement TARGET_USE_BY_PIECES_INFRASTRUCTURE_P.  */
+
+static bool
+arc_use_by_pieces_infrastructure_p (unsigned int size,
+				    unsigned int align,
+				    enum by_pieces_operation op,
+				    bool speed_p)
+{
+  /* Let the movmem expander handle small block moves.  */
+  if (op == MOVE_BY_PIECES_P)
+    return false;
+
+  return default_use_by_pieces_infrastructure_p (size, align, op, speed_p);
+}
+
 struct gcc_target targetm = TARGET_INITIALIZER;
 
 #include "gt-arc.h"
diff --git a/gcc/config/arc/arc.h b/gcc/config/arc/arc.h
index d40f5c3..2d27787 100644
--- a/gcc/config/arc/arc.h
+++ b/gcc/config/arc/arc.h
@@ -1553,12 +1553,6 @@ extern int arc_return_address_regs[4];
    in one reasonably fast instruction.  */
 #define MOVE_MAX 4
 
-/* Let the movmem expander handle small block moves.  */
-#define MOVE_BY_PIECES_P(LEN, ALIGN)  0
-#define CAN_MOVE_BY_PIECES(SIZE, ALIGN) \
-  (move_by_pieces_ninsns (SIZE, ALIGN, MOVE_MAX_PIECES + 1) \
-   < (unsigned int) MOVE_RATIO (!optimize_size))
-
 /* Undo the effects of the movmem pattern presence on STORE_BY_PIECES_P .  */
 #define MOVE_RATIO(SPEED) ((SPEED) ? 15 : 3)