Makefile.in (rtl-profile.o, [...]): Add GCC_H dependency.

	* Makefile.in (rtl-profile.o, value-prof.o): Add GCC_H dependency.
	* common.opt (fspeculative-prefetching): New.
	* flags.h (flag_speculative_prefetching_set): Declare.
	* gcov-io.c (gcov_write_counter, gcov_read_counter): Allow negative
	values.
	* opts.c (flag_sepculative_prefetching_set): New variable.
	(common_handle_option): Handle -fspeculative-prefetching.
	* passes.c (rest_of_compilation): Ditto.
	* profile.c (instrument_values, compute_value_histograms, branch_prob):
	Use vectors instead of arrays.
	* toplev.c (process_options): Handle -fspeculative-prefetching.
	* rtl-profile.c: Include ggc.h.
	(rtl_gen_interval_profiler, rtl_gen_pow2_profiler,
	rtl_gen_one_value_profiler_no_edge_manipulation,
	rtl_gen_one_value_profiler, rtl_gen_const_delta_profiler): Type of
	argument changed.
	* tree-profile.c (tree_gen_interval_profiler, tree_gen_pow2_profiler,
	tree_gen_one_value_profiler, tree_gen_const_delta_profiler): Type of
	argument changed.
	* value-prof.c: Include ggc.h.
	(NOPREFETCH_RANGE_MIN, NOPREFETCH_RANGE_MAX): New
	macros.
	(insn_prefetch_values_to_profile, find_mem_reference_1,
	find_mem_reference_2, find_mem_reference, gen_speculative_prefetch,
	speculative_prefetching_transform): New.
	(value_profile_transformations): Call speculative_prefetching_transform.
	(insn_values_to_profile): Call insn_prefetch_values_to_profile.
	(insn_divmod_values_to_profile, rtl_find_values_to_profile,
	tree_find_values_to_profile, find_values to profile): Use vectors
	instead of arrays.
	(free_profiled_values): Removed.
	* value-prof.h (struct histogram_value): Renamed to
	struct histogram_value_t.
	(histogram_value, histogram_values): New types.
	(find_values_to_profile): Declaration changed.
	(free_profiled_values): Removed.
	(struct profile_hooks): Type of argument of the hooks changed to
	histogram_value.
	* doc/invoke.texi (-fspeculative-prefetching): Document.

From-SVN: r86930

1 files changed, 16 insertions, 1 deletions

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 96b0fce..b4efeb4 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -311,7 +311,7 @@ Objective-C and Objective-C++ Dialects}.
 -fsched-stalled-insns=@var{n} -sched-stalled-insns-dep=@var{n} @gol
 -fsched2-use-superblocks @gol
 -fsched2-use-traces -freschedule-modulo-scheduled-loops @gol
--fsignaling-nans -fsingle-precision-constant  @gol
+-fsignaling-nans -fsingle-precision-constant  -fspeculative-prefetching @gol
 -fstrength-reduce  -fstrict-aliasing  -ftracer  -fthread-jumps @gol
 -funroll-all-loops  -funroll-loops  -fpeel-loops @gol
 -funswitch-loops  -fold-unroll-loops  -fold-unroll-all-loops @gol
@@ -5011,6 +5011,21 @@ and actually performs the optimizations based on them.
 Currently the optimizations include specialization of division operation
 using the knowledge about the value of the denominator.
 
+@item -fspeculative-prefetching
+@opindex fspeculative-prefetching
+If combined with @option{-fprofile-arcs}, it instructs the compiler to add
+a code to gather information about addresses of memory references in the
+program.
+
+With @option{-fbranch-probabilities}, it reads back the data gathered
+and issues prefetch instructions according to them.  In addition to the opportunities
+noticed by @option{-fprefetch-loop-arrays}, it also notices more complicated
+memory access patterns -- for example accesses to the data stored in linked
+list whose elements are usually allocated sequentially.
+
+In order to prevent issuing double prefetches, usage of
+@option{-fspeculative-prefetching} implies @option{-fno-prefetch-loop-arrays}.
+
 Enabled with @option{-fprofile-generate} and @option{-fprofile-use}.
 
 @item -frename-registers