Functions
static bool	should_duplicate_loop_header_p (basic_block header, struct loop loop, int limit)
bool	do_while_loop_p ()
static unsigned int	copy_loop_headers ()
static bool	gate_ch ()
gimple_opt_pass *	make_pass_ch ()

Function Documentation

static unsigned int copy_loop_headers ( )

static

For all loops, copy the condition at the end of the loop body in front
   of the loop.  This is beneficial since it increases efficiency of
   code motion optimizations.  It also saves one jump on entry to the loop.

References cfun, edge_def::dest, do_while_loop_p(), dump_file, dump_flags, flow_bb_inside_loop_p(), free(), gimple_assign_rhs_code(), gimple_duplicate_sese_region(), gimple_set_no_warning(), gsi_end_p(), gsi_next(), gsi_start_bb(), gsi_stmt(), loop::header, basic_block_def::index, is_gimple_assign(), limit, loop_latch_edge(), loop_optimizer_finalize(), loop_optimizer_init(), loop_preheader_edge(), LOOPS_HAVE_PREHEADERS, LOOPS_HAVE_SIMPLE_LATCHES, loop::num, number_of_loops(), propagate_threaded_block_debug_into(), should_duplicate_loop_header_p(), single_pred_edge(), single_pred_p(), split_edge(), edge_def::src, tcc_comparison, and update_ssa().

bool do_while_loop_p ( )

Checks whether LOOP is a do-while style loop.

References loop::header, last_and_only_stmt(), last_stmt(), and loop::latch.

static bool gate_ch ( )

static

gimple_opt_pass* make_pass_ch ( )

static bool should_duplicate_loop_header_p	(	basic_block	header,
		struct loop *	loop,
		int *	limit
	)

static

@verbatim Loop header copying on trees.

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/.

Duplicates headers of loops if they are small enough, so that the statements
   in the loop body are always executed when the loop is entered.  This
   increases effectiveness of code motion optimizations, and reduces the need
   for loop preconditioning.

Check whether we should duplicate HEADER of LOOP.  At most *LIMIT
   instructions should be duplicated, limit is decreased by the actual
   amount.

References basic_block_def::aux, eni_size_weights, estimate_num_insns(), flow_bb_inside_loop_p(), gsi_end_p(), gsi_next(), gsi_start_bb(), gsi_stmt(), loop::header, is_gimple_call(), is_gimple_debug(), last, last_stmt(), optimize_loop_for_size_p(), single_pred_p(), single_succ_p(), and basic_block_def::succs.

Referenced by copy_loop_headers().

Functions

Function Documentation