+2012-07-22 Steven Bosscher <steven@gcc.gnu.org>
+
+ * opts.c (common_handle_option): Do not set
+ flag_value_profile_transformations for -fprofile-generate.
+ * profile.c (instrument_values): Use COUNTER_FOR_HIST_TYPE.
+ (BB_TO_GCOV_INDEX): Remove.
+ (output_location): Don't use it.
+ (branch_prob): Likewise. Don't fiddle with the index of
+ ENTRY_BLOCK_PTR and EXIT_BLOCK_PTR. Use clear_aux_for_blocks.
+ (find_spanning_tree):
+ * gcov.c (struct function_info): Document that blocks 0 and 1
+ are the entry resp. exit blocks in gcov, too, like in GCC itself.
+ (solve_flow_graph): Use ENTRY_BLOCK and EXIT_BLOCK for special
+ blocks identification.
+ (output_lines): Likewise.
+ * value-prof.c (gimple_value_profile_transformations): Do not
+ test flag_value_profile_transformations again.
+ (gimple_ic_transform): Take a gimple_stmt_iterator like all other
+ transformation functions.
+ (gimple_values_to_profile):
+ Don't test flag_value_profile_transformations
+ * tree-profile.c (tree_profiling): Assert that the cgraph is in
+ the CGRAPH_STATE_IPA_SSA state.
+ Do not set, or look at, after_tree_profile.
+ * function.h (struct function): Remove after_tree_profile bit.
+ * omp-low.c (expand_omp_taskreg): Don't set after_tree_profile.
+ * tree-inline.c (initialize_cfun): Don't copy it.
+ * lto-streamer-out.c (output_struct_function_base): Don't stream it.
+ * lto-streamer-in.c (input_struct_function_base): Likewise.
+
2012-07-22 Oleg Endo <olegendo@gcc.gnu.org>
* config/sh/sh.h (TARGET_DYNSHIFT): New macro.
return the address of where it has put a structure value. */
unsigned int returns_pcc_struct : 1;
- /* Nonzero if pass_tree_profile was run on this function. */
- unsigned int after_tree_profile : 1;
-
/* Nonzero if this function has local DECL_HARD_REGISTER variables.
In this case code motion has to be done more carefully. */
unsigned int has_local_explicit_reg_vars : 1;
/* The code validates that the profile information read in corresponds
to the code currently being compiled. Rather than checking for
- identical files, the code below computes a checksum on the CFG
+ identical files, the code below compares a checksum on the CFG
(based on the order of basic blocks and the arcs in the CFG). If
- the CFG checksum in the gcda file match the CFG checksum for the
- code currently being compiled, the profile data will be used. */
+ the CFG checksum in the gcda file match the CFG checksum in the
+ gcno file, the profile data will be used. */
/* This is the size of the buffer used to read in source file lines. */
/* The graph contains at least one fake incoming edge. */
unsigned has_catch : 1;
- /* Array of basic blocks. */
+ /* Array of basic blocks. Like in GCC, the entry block is
+ at blocks[0] and the exit block is at blocks[1]. */
+#define ENTRY_BLOCK (0)
+#define EXIT_BLOCK (1)
block_t *blocks;
unsigned num_blocks;
unsigned blocks_executed;
bbg_file_name, fn->name);
else
{
- if (fn->blocks[0].num_pred)
+ if (fn->blocks[ENTRY_BLOCK].num_pred)
fnotice (stderr, "%s:'%s' has arcs to entry block\n",
bbg_file_name, fn->name);
else
/* We can't deduce the entry block counts from the lack of
predecessors. */
- fn->blocks[0].num_pred = ~(unsigned)0;
+ fn->blocks[ENTRY_BLOCK].num_pred = ~(unsigned)0;
- if (fn->blocks[fn->num_blocks - 1].num_succ)
+ if (fn->blocks[EXIT_BLOCK].num_succ)
fnotice (stderr, "%s:'%s' has arcs from exit block\n",
bbg_file_name, fn->name);
else
/* Likewise, we can't deduce exit block counts from the lack
of its successors. */
- fn->blocks[fn->num_blocks - 1].num_succ = ~(unsigned)0;
+ fn->blocks[EXIT_BLOCK].num_succ = ~(unsigned)0;
}
/* Propagate the measured counts, this must be done in the same
}
}
-/* Format a HOST_WIDE_INT as either a percent ratio, or absolute
+/* Format a GCOV_TYPE integer as either a percent ratio, or absolute
count. If dp >= 0, format TOP/BOTTOM * 100 to DP decimal places.
If DP is zero, no decimal point is printed. Only print 100% when
TOP==BOTTOM and only print 0% when TOP=0. If dp < 0, then simply
{
for (; fn && fn->line == line_num; fn = fn->line_next)
{
- arc_t *arc = fn->blocks[fn->num_blocks - 1].pred;
- gcov_type return_count = fn->blocks[fn->num_blocks - 1].count;
+ arc_t *arc = fn->blocks[EXIT_BLOCK].pred;
+ gcov_type return_count = fn->blocks[EXIT_BLOCK].count;
+ gcov_type called_count = fn->blocks[ENTRY_BLOCK].count;
for (; arc; arc = arc->pred_next)
if (arc->fake)
fprintf (gcov_file, "function %s", fn->name);
fprintf (gcov_file, " called %s",
- format_gcov (fn->blocks[0].count, 0, -1));
+ format_gcov (called_count, 0, -1));
fprintf (gcov_file, " returned %s",
- format_gcov (return_count, fn->blocks[0].count, 0));
+ format_gcov (return_count, called_count, 0));
fprintf (gcov_file, " blocks executed %s",
format_gcov (fn->blocks_executed, fn->num_blocks - 2, 0));
fprintf (gcov_file, "\n");
bp = streamer_read_bitpack (ib);
fn->is_thunk = bp_unpack_value (&bp, 1);
fn->has_local_explicit_reg_vars = bp_unpack_value (&bp, 1);
- fn->after_tree_profile = bp_unpack_value (&bp, 1);
fn->returns_pcc_struct = bp_unpack_value (&bp, 1);
fn->returns_struct = bp_unpack_value (&bp, 1);
fn->can_throw_non_call_exceptions = bp_unpack_value (&bp, 1);
bp = bitpack_create (ob->main_stream);
bp_pack_value (&bp, fn->is_thunk, 1);
bp_pack_value (&bp, fn->has_local_explicit_reg_vars, 1);
- bp_pack_value (&bp, fn->after_tree_profile, 1);
bp_pack_value (&bp, fn->returns_pcc_struct, 1);
bp_pack_value (&bp, fn->returns_struct, 1);
bp_pack_value (&bp, fn->can_throw_non_call_exceptions, 1);
entry_stmt = last_stmt (region->entry);
child_fn = gimple_omp_taskreg_child_fn (entry_stmt);
child_cfun = DECL_STRUCT_FUNCTION (child_fn);
- /* If this function has been already instrumented, make sure
- the child function isn't instrumented again. */
- child_cfun->after_tree_profile = cfun->after_tree_profile;
entry_bb = region->entry;
exit_bb = region->exit;
opts->x_profile_arc_flag = value;
if (!opts_set->x_flag_profile_values)
opts->x_flag_profile_values = value;
- if (!opts_set->x_flag_value_profile_transformations)
- opts->x_flag_value_profile_transformations = value;
if (!opts_set->x_flag_inline_functions)
opts->x_flag_inline_functions = value;
/* FIXME: Instrumentation we insert makes ipa-reference bitmaps
static void
instrument_values (histogram_values values)
{
- unsigned i, t;
+ unsigned i;
/* Emit code to generate the histograms before the insns. */
for (i = 0; i < VEC_length (histogram_value, values); i++)
{
histogram_value hist = VEC_index (histogram_value, values, i);
- switch (hist->type)
- {
- case HIST_TYPE_INTERVAL:
- t = GCOV_COUNTER_V_INTERVAL;
- break;
-
- case HIST_TYPE_POW2:
- t = GCOV_COUNTER_V_POW2;
- break;
-
- case HIST_TYPE_SINGLE_VALUE:
- t = GCOV_COUNTER_V_SINGLE;
- break;
-
- case HIST_TYPE_CONST_DELTA:
- t = GCOV_COUNTER_V_DELTA;
- break;
+ unsigned t = COUNTER_FOR_HIST_TYPE (hist->type);
- case HIST_TYPE_INDIR_CALL:
- t = GCOV_COUNTER_V_INDIR;
- break;
-
- case HIST_TYPE_AVERAGE:
- t = GCOV_COUNTER_AVERAGE;
- break;
-
- case HIST_TYPE_IOR:
- t = GCOV_COUNTER_IOR;
- break;
-
- default:
- gcc_unreachable ();
- }
if (!coverage_counter_alloc (t, hist->n_counters))
continue;
free (histogram_counts[t]);
}
-/* The entry basic block will be moved around so that it has index=1,
- there is nothing at index 0 and the exit is at n_basic_block. */
-#define BB_TO_GCOV_INDEX(bb) ((bb)->index - 1)
/* When passed NULL as file_name, initialize.
When passed something else, output the necessary commands to change
line to LINE and offset to FILE_NAME. */
if (!*offset)
{
*offset = gcov_write_tag (GCOV_TAG_LINES);
- gcov_write_unsigned (BB_TO_GCOV_INDEX (bb));
+ gcov_write_unsigned (bb->index);
name_differs = line_differs=true;
}
}
}
-/* Instrument and/or analyze program behavior based on program flow graph.
- In either case, this function builds a flow graph for the function being
- compiled. The flow graph is stored in BB_GRAPH.
+/* Instrument and/or analyze program behavior based on program the CFG.
+
+ This function creates a representation of the control flow graph (of
+ the function being compiled) that is suitable for the instrumentation
+ of edges and/or converting measured edge counts to counts on the
+ complete CFG.
When FLAG_PROFILE_ARCS is nonzero, this function instruments the edges in
the flow graph that are needed to reconstruct the dynamic behavior of the
- flow graph.
+ flow graph. This data is written to the gcno file for gcov.
When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary
- information from a data file containing edge count information from previous
- executions of the function being compiled. In this case, the flow graph is
- annotated with actual execution counts, which are later propagated into the
- rtl for optimization purposes.
+ information from the gcda file containing edge count information from
+ previous executions of the function being compiled. In this case, the
+ control flow graph is annotated with actual execution counts by
+ compute_branch_probabilities().
Main entry point of this file. */
lineno_checksum = coverage_compute_lineno_checksum ();
/* Write the data from which gcov can reconstruct the basic block
- graph and function line numbers */
-
+ graph and function line numbers (the gcno file). */
if (coverage_begin_function (lineno_checksum, cfg_checksum))
{
gcov_position_t offset;
gcov_write_unsigned (0);
gcov_write_length (offset);
- /* Keep all basic block indexes nonnegative in the gcov output.
- Index 0 is used for entry block, last index is for exit
- block. */
- ENTRY_BLOCK_PTR->index = 1;
- EXIT_BLOCK_PTR->index = last_basic_block;
-
/* Arcs */
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
{
edge_iterator ei;
offset = gcov_write_tag (GCOV_TAG_ARCS);
- gcov_write_unsigned (BB_TO_GCOV_INDEX (bb));
+ gcov_write_unsigned (bb->index);
FOR_EACH_EDGE (e, ei, bb->succs)
{
&& e->src->next_bb == e->dest)
flag_bits |= GCOV_ARC_FALLTHROUGH;
- gcov_write_unsigned (BB_TO_GCOV_INDEX (e->dest));
+ gcov_write_unsigned (e->dest->index);
gcov_write_unsigned (flag_bits);
}
}
gcov_write_length (offset);
}
- ENTRY_BLOCK_PTR->index = ENTRY_BLOCK;
- EXIT_BLOCK_PTR->index = EXIT_BLOCK;
-
/* Line numbers. */
/* Initialize the output. */
output_location (NULL, 0, NULL, NULL);
}
}
-#undef BB_TO_GCOV_INDEX
-
if (flag_profile_values)
gimple_find_values_to_profile (&values);
}
}
- FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
- bb->aux = NULL;
+ clear_aux_for_blocks ();
}
\f
/* Perform file-level initialization for branch-prob processing. */
cfun->can_delete_dead_exceptions = src_cfun->can_delete_dead_exceptions;
cfun->returns_struct = src_cfun->returns_struct;
cfun->returns_pcc_struct = src_cfun->returns_pcc_struct;
- cfun->after_tree_profile = src_cfun->after_tree_profile;
init_empty_tree_cfg ();
varpool_finalize_decl (ic_gcov_type_ptr_var);
}
+/* Create the type and function decls for the interface with gcov. */
+
void
gimple_init_edge_profiler (void)
{
/* Insert code:
- __gcov_indirect_call_counters = get_relevant_counter_ptr ();
- __gcov_indirect_call_callee = (void *) indirect call argument;
+ stmt1: __gcov_indirect_call_counters = get_relevant_counter_ptr ();
+ stmt2: tmp1 = (void *) (indirect call argument value)
+ stmt3: __gcov_indirect_call_callee = tmp1;
*/
tmp1 = create_tmp_reg (ptr_void, "PROF");
gimple_init_edge_profiler ();
+ /* Insert code:
+
+ stmt1: __gcov_indirect_call_profiler (__gcov_indirect_call_counters,
+ current_function_funcdef_no,
+ ¤t_function_decl,
+ __gcov_indirect_call_callee);
+ */
gsi = gsi_after_labels (single_succ (ENTRY_BLOCK_PTR));
cur_func = force_gimple_operand_gsi (&gsi,
{
struct cgraph_node *node;
- /* Don't profile functions produced at destruction time, particularly
- the gcov datastructure initializer. Don't profile if it has been
- already instrumented either (when OpenMP expansion creates
- child function from already instrumented body). */
- if (cgraph_state == CGRAPH_STATE_FINISHED)
- return 0;
+ /* This is a small-ipa pass that gets called only once, from
+ cgraphunit.c:ipa_passes(). */
+ gcc_assert (cgraph_state == CGRAPH_STATE_IPA_SSA);
init_node_map();
continue;
/* Don't profile functions produced for builtin stuff. */
- if (DECL_SOURCE_LOCATION (node->symbol.decl) == BUILTINS_LOCATION
- || DECL_STRUCT_FUNCTION (node->symbol.decl)->after_tree_profile)
+ if (DECL_SOURCE_LOCATION (node->symbol.decl) == BUILTINS_LOCATION)
continue;
push_cfun (DECL_STRUCT_FUNCTION (node->symbol.decl));
/* Local pure-const may imply need to fixup the cfg. */
if (execute_fixup_cfg () & TODO_cleanup_cfg)
cleanup_tree_cfg ();
+
branch_prob ();
if (! flag_branch_probabilities
continue;
/* Don't profile functions produced for builtin stuff. */
- if (DECL_SOURCE_LOCATION (node->symbol.decl) == BUILTINS_LOCATION
- || DECL_STRUCT_FUNCTION (node->symbol.decl)->after_tree_profile)
+ if (DECL_SOURCE_LOCATION (node->symbol.decl) == BUILTINS_LOCATION)
continue;
cgraph_set_const_flag (node, false, false);
continue;
/* Don't profile functions produced for builtin stuff. */
- if (DECL_SOURCE_LOCATION (node->symbol.decl) == BUILTINS_LOCATION
- || DECL_STRUCT_FUNCTION (node->symbol.decl)->after_tree_profile)
+ if (DECL_SOURCE_LOCATION (node->symbol.decl) == BUILTINS_LOCATION)
continue;
push_cfun (DECL_STRUCT_FUNCTION (node->symbol.decl));
}
}
- cfun->after_tree_profile = 1;
update_ssa (TODO_update_ssa);
rebuild_cgraph_edges ();
1) Division/modulo specialization. Provided that we can determine that the
operands of the division have some special properties, we may use it to
produce more effective code.
- 2) Speculative prefetching. If we are able to determine that the difference
- between addresses accessed by a memory reference is usually constant, we
- may add the prefetch instructions.
- FIXME: This transformation was removed together with RTL based value
- profiling.
- 3) Indirect/virtual call specialization. If we can determine most
+ 2) Indirect/virtual call specialization. If we can determine most
common function callee in indirect/virtual call. We can use this
information to improve code effectiveness (especially info for
- inliner).
+ the inliner).
- Every such optimization should add its requirements for profiled values to
- insn_values_to_profile function. This function is called from branch_prob
- in profile.c and the requested values are instrumented by it in the first
- compilation with -fprofile-arcs. The optimization may then read the
- gathered data in the second compilation with -fbranch-probabilities.
+ 3) Speculative prefetching. If we are able to determine that the difference
+ between addresses accessed by a memory reference is usually constant, we
+ may add the prefetch instructions.
+ FIXME: This transformation was removed together with RTL based value
+ profiling.
- The measured data is pointed to from the histograms
- field of the statement annotation of the instrumented insns. It is
- kept as a linked list of struct histogram_value_t's, which contain the
- same information as above. */
+ Value profiling internals
+ ==========================
+
+ Every value profiling transformation starts with defining what values
+ to profile. There are different histogram types (see HIST_TYPE_* in
+ value-prof.h) and each transformation can request one or more histogram
+ types per GIMPLE statement. The function gimple_find_values_to_profile()
+ collects the values to profile in a VEC, and adds the number of counters
+ required for the different histogram types.
+
+ For a -fprofile-generate run, the statements for which values should be
+ recorded, are instrumented in instrument_values(). The instrumentation
+ is done by helper functions that can be found in tree-profile.c, where
+ new types of histograms can be added if necessary.
+
+ After a -fprofile-use, the value profiling data is read back in by
+ compute_value_histograms() that translates the collected data to
+ histograms and attaches them to the profiled statements via
+ gimple_add_histogram_value(). Histograms are stored in a hash table
+ that is attached to every intrumented function, see VALUE_HISTOGRAMS
+ in function.h.
+
+ The value-profile transformations driver is the function
+ gimple_value_profile_transformations(). It traverses all statements in
+ the to-be-transformed function, and looks for statements with one or
+ more histograms attached to it. If a statement has histograms, the
+ transformation functions are called on the statement.
+
+ Limitations / FIXME / TODO:
+ * Only one histogram of each type can be associated with a statement.
+ * Currently, HIST_TYPE_CONST_DELTA is not implemented.
+ (This type of histogram was originally used to implement a form of
+ stride profiling based speculative prefetching to improve SPEC2000
+ scores for memory-bound benchmarks, mcf and equake. However, this
+ was an RTL value-profiling transformation, and those have all been
+ removed.)
+ * Some value profile transformations are done in builtins.c (?!)
+ * Updating of histograms needs some TLC.
+ * The value profiling code could be used to record analysis results
+ from non-profiling (e.g. VRP).
+ * Adding new profilers should be simplified, starting with a cleanup
+ of what-happens-where andwith making gimple_find_values_to_profile
+ and gimple_value_profile_transformations table-driven, perhaps...
+*/
static tree gimple_divmod_fixed_value (gimple, tree, int, gcov_type, gcov_type);
static tree gimple_mod_pow2 (gimple, int, gcov_type, gcov_type);
static bool gimple_mod_pow2_value_transform (gimple_stmt_iterator *);
static bool gimple_mod_subtract_transform (gimple_stmt_iterator *);
static bool gimple_stringops_transform (gimple_stmt_iterator *);
-static bool gimple_ic_transform (gimple);
+static bool gimple_ic_transform (gimple_stmt_iterator *);
/* Allocate histogram value. */
{
histogram_value hist;
for (hist = gimple_histogram_value (fun, stmt); hist; hist = hist->hvalue.next)
- dump_histogram_value (dump_file, hist);
+ dump_histogram_value (dump_file, hist);
}
/* Remove all histograms associated with STMT. */
will be added before the current statement, and that the
current statement remain valid (although possibly
modified) upon return. */
- if (flag_value_profile_transformations
- && (gimple_mod_subtract_transform (&gsi)
- || gimple_divmod_fixed_value_transform (&gsi)
- || gimple_mod_pow2_value_transform (&gsi)
- || gimple_stringops_transform (&gsi)
- || gimple_ic_transform (stmt)))
+ if (gimple_mod_subtract_transform (&gsi)
+ || gimple_divmod_fixed_value_transform (&gsi)
+ || gimple_mod_pow2_value_transform (&gsi)
+ || gimple_stringops_transform (&gsi)
+ || gimple_ic_transform (&gsi))
{
stmt = gsi_stmt (gsi);
changed = true;
*/
static bool
-gimple_ic_transform (gimple stmt)
+gimple_ic_transform (gimple_stmt_iterator *gsi)
{
+ gimple stmt = gsi_stmt (*gsi);
histogram_value histogram;
gcov_type val, count, all, bb_all;
gcov_type prob;
static void
gimple_values_to_profile (gimple stmt, histogram_values *values)
{
- if (flag_value_profile_transformations)
- {
- gimple_divmod_values_to_profile (stmt, values);
- gimple_stringops_values_to_profile (stmt, values);
- gimple_indirect_call_to_profile (stmt, values);
- }
+ gimple_divmod_values_to_profile (stmt, values);
+ gimple_stringops_values_to_profile (stmt, values);
+ gimple_indirect_call_to_profile (stmt, values);
}
void
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