[ARC] Reimplement ZOL support.

[ARC] Reimplement ZOL support.

2017-05-22  Claudiu Zissulescu <claziss@synopsys.com>

	* config/arc/arc-c.c (__ARC_LPC_WIDTH__): Add builtin define.
	* config/arc/arc.c (ARC_MAX_LOOP_LENGTH): Define.
	(arc_conditional_register_usage): Remove ARC600 lp_count
	exception.
	(arc_file_start): Emit Tag_ARC_CPU_variation.
	(arc_can_use_doloop_p): New conditions to use ZOLs.
	(hwloop_fail): New function.
	(hwloop_optimize): Likewise.
	(hwloop_pattern_reg): Likewise.
	(arc_doloop_hooks): New struct, to be used with reorg_loops.
	(arc_reorg_loops): New function, calls reorg_loops.
	(arc_reorg): Call arc_reorg_loops.  Remove old ZOL handling.
	(arc600_corereg_hazard): Remove ZOL checking, case handled by
	hwloop_optimize.
	(arc_loop_hazard): Remove function, functionality moved into
	hwloop_optimize.
	(arc_hazard): Remove arc_loop_hazard call.
	(arc_adjust_insn_length): Remove ZOL handling, functionality moved
	into hwloop_optimize.
	(arc_label_align): Remove ZOL handling.
	* config/arc/arc.h (LOOP_ALIGN): Changed to 0.
	* config/arc/arc.md (doloop_begin): Remove pattern.
	(doloop_begin_i): Likewise.
	(doloop_end_i): Likewise.
	(doloop_fallback): Likewise.
	(doloop_fallback_m): Likewise.
	(doloop_end): Reimplement expand.
	(arc_lp): New pattern for LP instruction.
	(loop_end): New pattern.
	(loop_fail): Likewise.
	(decrement_and_branch_until_zero): Likewise.
	* config/arc/arc.opt (mlpc-width): New option.
	* doc/invoke.texi (mlpc-width): Document option.

testsuite/
2017-05-22  Claudiu Zissulescu <claziss@synopsys.com>

 	    * gcc.target/arc/loop-1.c: Deleted.

From-SVN: r251589