hw-doloop.c: New file.

	* hw-doloop.c: New file.
	* hw-doloop.h: New file.
	* Makefile.in (OBJS): Add hw-doloop.o.
	(hw-doloop.o): New rule.
	($(obj_out_file)): Add hw-doloop.h dependency.
	* config/bfin/bfin.c: Include "hw-doloop.h".
	(loop_info, DEF_VEC_P for loop_info, loop_info_d): Remove.
	(bfin_dump_loops, bfin_bb_in_loop, bfin_scan_loop): Remove.
	(hwloop_optimize): Renamed from bfin_optimize_loop.  Argument
	type changed to hwloop_info.  Return bool, true if the loop was
	successfully optimized.  Remove code that was moved to
	hw-doloop.c, and adjust other parts.
	(hwloop_fail): New static function, containing parts that used
	to be in bfin_optimize_loop.
	(bfin_discover_loop, bfin_discover_loops, free_loops,
	bfin_reorder_loops): Remove.
	(hwloop_pattern_reg): New static function.
	(bfin_doloop_hooks): New variable.
	(bfin_reorg_loops): Remove most code, call reorg_loops.
	* config/bfin/bfin.md (doloop_end splitter): Also enable if
	loop counter is a memory_operand.

From-SVN: r175985

1 files changed, 157 insertions, 0 deletions

diff --git a/gcc/hw-doloop.h b/gcc/hw-doloop.h
new file mode 100644
index 00000000000..006b67953b2
--- /dev/null
+++ b/gcc/hw-doloop.h
@@ -0,0 +1,157 @@
+/* Code to analyze doloop loops in order for targets to perform late
+   optimizations converting doloops to other forms of hardware loops.
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+/* We need to keep a vector of loops */
+typedef struct hwloop_info_d *hwloop_info;
+DEF_VEC_P (hwloop_info);
+DEF_VEC_ALLOC_P (hwloop_info,heap);
+
+/* Information about a loop we have found (or are in the process of
+   finding).  */
+struct GTY (()) hwloop_info_d
+{
+  /* loop number, for dumps */
+  int loop_no;
+
+  /* Next loop in the graph. */
+  hwloop_info next;
+
+  /* Vector of blocks only within the loop, including those within
+     inner loops.  */
+  VEC (basic_block, heap) *blocks;
+
+  /* Same information in a bitmap.  */
+  bitmap block_bitmap;
+
+  /* Vector of inner loops within this loop.  Includes loops of every
+     nesting level.  */
+  VEC (hwloop_info, heap) *loops;
+
+  /* All edges that jump into the loop.  */
+  VEC(edge, gc) *incoming;
+
+  /* The ports currently using this infrastructure can typically
+     handle two cases: all incoming edges have the same destination
+     block, or all incoming edges have the same source block.  These
+     two members are set to the common source or destination we found,
+     or NULL if different blocks were found.  If both are NULL the
+     loop can't be optimized.  */
+  basic_block incoming_src;
+  basic_block incoming_dest;
+
+  /* First block in the loop.  This is the one branched to by the loop_end
+     insn.  */
+  basic_block head;
+
+  /* Last block in the loop (the one with the loop_end insn).  */
+  basic_block tail;
+
+  /* The successor block of the loop.  This is the one the loop_end insn
+     falls into.  */
+  basic_block successor;
+
+  /* The last instruction in the tail.  */
+  rtx last_insn;
+
+  /* The loop_end insn.  */
+  rtx loop_end;
+
+  /* The iteration register.  */
+  rtx iter_reg;
+
+  /* The new label placed at the beginning of the loop. */
+  rtx start_label;
+
+  /* The new label placed at the end of the loop. */
+  rtx end_label;
+
+  /* The length of the loop.  */
+  int length;
+
+  /* The nesting depth of the loop.  Innermost loops are given a depth
+     of 1.  Only successfully optimized doloops are counted; if an inner
+     loop was marked as bad, it does not increase the depth of its parent
+     loop.
+     This value is valid when the target's optimize function is called.  */
+  int depth;
+
+  /* True if we can't optimize this loop.  */
+  bool bad;
+
+  /* True if we have visited this loop during the optimization phase.  */
+  bool visited;
+
+  /* The following values are collected before calling the target's optimize
+     function and are not valid earlier.  */
+  
+  /* Record information about control flow: whether the loop has calls
+     or asm statements, whether it has edges that jump out of the loop,
+     or edges that jump within the loop.  */
+  bool has_call;
+  bool has_asm;
+  bool jumps_within;
+  bool jumps_outof;
+
+  /* True if there is an instruction other than the doloop_end which uses the
+     iteration register.  */
+  bool iter_reg_used;
+  /* True if the iteration register lives past the doloop instruction.  */
+  bool iter_reg_used_outside;
+
+  /* Hard registers set at any point in the loop, except for the loop counter
+     register's set in the doloop_end instruction.  */
+  HARD_REG_SET regs_set_in_loop;
+};
+
+/* A set of hooks to be defined by a target that wants to use the reorg_loops
+   functionality.
+
+   reorg_loops is intended to handle cases where special hardware loop
+   setup instructions are required before the loop, for example to set
+   up loop counter registers that are not exposed to the register
+   allocator, or to inform the hardware about loop bounds.
+
+   reorg_loops performs analysis to discover loop_end patterns created
+   by the earlier loop-doloop pass, and sets up a hwloop_info
+   structure for each such insn it finds.  It then tries to discover
+   the basic blocks containing the loop by tracking the lifetime of
+   the iteration register.
+
+   If a valid loop can't be found, the FAIL function is called;
+   otherwise the OPT function is called for each loop, visiting
+   innermost loops first and ascending.  */
+struct hw_doloop_hooks
+{
+  /* Examine INSN.  If it is a suitable doloop_end pattern, return the
+     iteration register, which should be a single hard register.
+     Otherwise, return NULL_RTX.  */
+  rtx (*end_pattern_reg) (rtx insn);
+  /* Optimize LOOP.  The target should perform any additional analysis
+     (e.g. checking that the loop isn't too long), and then perform
+     its transformations.  Return true if successful, false if the
+     loop should be marked bad.  If it returns false, the FAIL
+     function is called.  */
+  bool (*opt) (hwloop_info loop);
+  /* Handle a loop that was marked bad for any reason.  This could be
+     used to split the doloop_end pattern.  */
+  void (*fail) (hwloop_info loop);
+};
+
+extern void reorg_loops (bool, struct hw_doloop_hooks *);