First phase of unifying the computation of profile scale factors/probabilities

and the actual scaling to use rounding divides:
- Add new macro GCOV_COMPUTE_SCALE to basic-block.h to compute the scale
factor/probability via a rounding divide.
- Change all locations that already perform rounding divides (inline or via RDIV)
to use the appropriate helper: GCOV_COMPUTE_SCALE, apply_probability or
combine_probabilities.
- Change ipa-cp.c truncating divides to use rounding divides.
- Add comments to all other locations (currently using truncating divides) to
switch them to one of the helpers so they use a rounding divide.

Next phase will be to replace the locations using truncating divides, marked
with a comment here, into rounding divides via the helper methods.

2013-04-08  Teresa Johnson  <tejohnson@google.com>

	* basic-block.h (GCOV_COMPUTE_SCALE): Define.
	* ipa-inline-analysis.c (param_change_prob): Use helper rounding divide
        methods.
	(estimate_edge_size_and_time): Add comment to suggest using rounding
	methods.
	(estimate_node_size_and_time): Ditto.
	(remap_edge_change_prob): Use helper rounding divide methods.
	* value-prof.c (gimple_divmod_fixed_value_transform): Ditto.
	(gimple_mod_pow2_value_transform): Ditto.
	(gimple_mod_subtract_transform): Ditto.
	(gimple_ic_transform): Ditto.
	(gimple_stringops_transform): Ditto.
	* stmt.c (conditional_probability): Ditto.
	(emit_case_dispatch_table): Ditto.
	* lto-cgraph.c (merge_profile_summaries): Ditto.
	* tree-optimize.c (execute_fixup_cfg): Ditto.
	* cfgcleanup.c (try_forward_edges): Ditto.
	* cfgloopmanip.c (scale_loop_profile): Ditto.
	(loopify): Ditto.
	(duplicate_loop_to_header_edge): Ditto.
	(lv_adjust_loop_entry_edge): Ditto.
	* tree-vect-loop.c (vect_transform_loop): Ditto.
	* profile.c (compute_branch_probabilities): Ditto.
	* cfgbuild.c (compute_outgoing_frequencies): Ditto.
	* lto-streamer-in.c (input_cfg): Ditto.
	* gimple-streamer-in.c (input_bb): Ditto.
	* ipa-cp.c (update_profiling_info): Ditto.
	(update_specialized_profile): Ditto.
	* tree-vect-loop-manip.c (slpeel_tree_peel_loop_to_edge): Ditto.
	* cfg.c (update_bb_profile_for_threading): Add comment to suggest using
        rounding methods.
	* sched-rgn.c (compute_dom_prob_ps): Ditto.
	(compute_trg_info): Ditto.
	* cfgrtl.c (force_nonfallthru_and_redirect): Ditto.
	(purge_dead_edges): Ditto.
	* loop-unswitch.c (unswitch_loop): Ditto.
	* cgraphclones.c (cgraph_clone_edge): Ditto.
	(cgraph_clone_node): Ditto.
	* tree-inline.c (copy_bb): Ditto.
	(copy_edges_for_bb): Ditto.
	(initialize_cfun): Ditto.
	(copy_cfg_body): Ditto.
	(expand_call_inline): Ditto.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@197595 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 1 insertions, 0 deletions

diff --git a/gcc/cfg.c b/gcc/cfg.c
index 0c1e425a00d..2bcd790d306 100644
--- a/gcc/cfg.c
+++ b/gcc/cfg.c
@@ -848,6 +848,7 @@ update_bb_profile_for_threading (basic_block bb, int edge_frequency,
   /* Compute the probability of TAKEN_EDGE being reached via threaded edge.
      Watch for overflows.  */
   if (bb->frequency)
+    /* Update to use GCOV_COMPUTE_SCALE.  */
     prob = edge_frequency * REG_BR_PROB_BASE / bb->frequency;
   else
     prob = 0;