From 1a277ec6ef25cddbf0518b679fa8f1928cd3d891 Mon Sep 17 00:00:00 2001
From: marxin <mliska@suse.cz>
Date: Thu, 27 Oct 2016 09:37:34 +0200
Subject: [PATCH] Make direct emission of time profiler counter
libgcc/ChangeLog:
2016-10-31 Martin Liska <mliska@suse.cz>
* libgcov-profiler.c (__gcov_time_profiler): Remove.
(__gcov_time_profiler_atomic): Likewise.
gcc/ChangeLog:
2016-10-31 Martin Liska <mliska@suse.cz>
* profile.c (instrument_values): Fix coding style.
(branch_prob): Use renamed function.
* tree-profile.c (init_ic_make_global_vars): Likewise.
(gimple_init_edge_profiler): Rename to
gimple_init_gcov_profiler.
tree_time_profiler_counter variable declaration.
(gimple_gen_time_profiler): Rewrite to do a direct gimple code
emission.
* value-prof.h: Remove an argument.
gcc/testsuite/ChangeLog:
2016-11-03 Martin Liska <mliska@suse.cz>
* gcc.dg/no_profile_instrument_function-attr-1.c: Update scanned
output.
* gcc.dg/tree-prof/time-profiler-3.c: New test.
---
gcc/profile.c | 14 +--
.../gcc.dg/no_profile_instrument_function-attr-1.c | 2 +-
gcc/testsuite/gcc.dg/tree-prof/time-profiler-3.c | 22 +++++
gcc/tree-profile.c | 106 ++++++++++++++++-----
gcc/value-prof.h | 5 +-
libgcc/libgcov-profiler.c | 23 +----
6 files changed, 111 insertions(+), 61 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-prof/time-profiler-3.c
@@ -192,15 +192,9 @@ instrument_values (histogram_values values)
gimple_gen_ior_profiler (hist, t, 0);
break;
- case HIST_TYPE_TIME_PROFILE:
- {
- basic_block bb =
- split_edge (single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
- gimple_stmt_iterator gsi = gsi_start_bb (bb);
-
- gimple_gen_time_profiler (t, 0, gsi);
- break;
- }
+ case HIST_TYPE_TIME_PROFILE:
+ gimple_gen_time_profiler (t, 0);
+ break;
default:
gcc_unreachable ();
@@ -1305,7 +1299,7 @@ branch_prob (void)
{
unsigned n_instrumented;
- gimple_init_edge_profiler ();
+ gimple_init_gcov_profiler ();
n_instrumented = instrument_edges (el);
@@ -19,5 +19,5 @@ int main ()
/* { dg-final { scan-tree-dump-times "__gcov0\\.main.* = PROF_edge_counter" 1 "optimized"} } */
/* { dg-final { scan-tree-dump-times "__gcov_indirect_call_profiler_v2" 1 "optimized" } } */
-/* { dg-final { scan-tree-dump-times "__gcov_time_profiler" 1 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "__gcov_time_profiler_counter = " 1 "optimized" } } */
/* { dg-final { scan-tree-dump-times "__gcov_init" 1 "optimized" } } */
new file mode 100644
@@ -0,0 +1,22 @@
+/* { dg-options "-O2 -fdump-ipa-profile -fprofile-update=atomic" } */
+/* { dg-require-effective-target profile_update_atomic } */
+
+__attribute__ ((noinline))
+int foo()
+{
+ return 0;
+}
+
+__attribute__ ((noinline))
+int bar()
+{
+ return 1;
+}
+
+int main ()
+{
+ return foo ();
+}
+/* { dg-final-use-not-autofdo { scan-ipa-dump-times "Read tp_first_run: 0" 1 "profile"} } */
+/* { dg-final-use-not-autofdo { scan-ipa-dump-times "Read tp_first_run: 1" 1 "profile"} } */
+/* { dg-final-use-not-autofdo { scan-ipa-dump-times "Read tp_first_run: 2" 1 "profile"} } */
@@ -56,9 +56,9 @@ static GTY(()) tree tree_interval_profiler_fn;
static GTY(()) tree tree_pow2_profiler_fn;
static GTY(()) tree tree_one_value_profiler_fn;
static GTY(()) tree tree_indirect_call_profiler_fn;
-static GTY(()) tree tree_time_profiler_fn;
static GTY(()) tree tree_average_profiler_fn;
static GTY(()) tree tree_ior_profiler_fn;
+static GTY(()) tree tree_time_profiler_counter;
static GTY(()) tree ic_void_ptr_var;
@@ -75,7 +75,7 @@ static GTY(()) tree ptr_void;
static void
init_ic_make_global_vars (void)
{
- tree gcov_type_ptr;
+ tree gcov_type_ptr;
ptr_void = build_pointer_type (void_type_node);
@@ -119,7 +119,7 @@ init_ic_make_global_vars (void)
/* Create the type and function decls for the interface with gcov. */
void
-gimple_init_edge_profiler (void)
+gimple_init_gcov_profiler (void)
{
tree interval_profiler_fn_type;
tree pow2_profiler_fn_type;
@@ -127,7 +127,6 @@ gimple_init_edge_profiler (void)
tree gcov_type_ptr;
tree ic_profiler_fn_type;
tree average_profiler_fn_type;
- tree time_profiler_fn_type;
const char *profiler_fn_name;
const char *fn_name;
@@ -201,17 +200,17 @@ gimple_init_edge_profiler (void)
= tree_cons (get_identifier ("leaf"), NULL,
DECL_ATTRIBUTES (tree_indirect_call_profiler_fn));
- /* void (*) (gcov_type *, gcov_type, void *) */
- time_profiler_fn_type
- = build_function_type_list (void_type_node,
- gcov_type_ptr, NULL_TREE);
- fn_name = concat ("__gcov_time_profiler", fn_suffix, NULL);
- tree_time_profiler_fn = build_fn_decl (fn_name, time_profiler_fn_type);
- free (CONST_CAST (char *, fn_name));
- TREE_NOTHROW (tree_time_profiler_fn) = 1;
- DECL_ATTRIBUTES (tree_time_profiler_fn)
- = tree_cons (get_identifier ("leaf"), NULL,
- DECL_ATTRIBUTES (tree_time_profiler_fn));
+ tree_time_profiler_counter
+ = build_decl (UNKNOWN_LOCATION, VAR_DECL,
+ get_identifier ("__gcov_time_profiler_counter"),
+ get_gcov_type ());
+ TREE_PUBLIC (tree_time_profiler_counter) = 1;
+ DECL_EXTERNAL (tree_time_profiler_counter) = 1;
+ TREE_STATIC (tree_time_profiler_counter) = 1;
+ DECL_ARTIFICIAL (tree_time_profiler_counter) = 1;
+ DECL_INITIAL (tree_time_profiler_counter) = NULL;
+
+ varpool_node::finalize_decl (tree_time_profiler_counter);
/* void (*) (gcov_type *, gcov_type) */
average_profiler_fn_type
@@ -239,7 +238,6 @@ gimple_init_edge_profiler (void)
DECL_ASSEMBLER_NAME (tree_pow2_profiler_fn);
DECL_ASSEMBLER_NAME (tree_one_value_profiler_fn);
DECL_ASSEMBLER_NAME (tree_indirect_call_profiler_fn);
- DECL_ASSEMBLER_NAME (tree_time_profiler_fn);
DECL_ASSEMBLER_NAME (tree_average_profiler_fn);
DECL_ASSEMBLER_NAME (tree_ior_profiler_fn);
}
@@ -426,7 +424,7 @@ gimple_gen_ic_func_profiler (void)
if (c_node->only_called_directly_p ())
return;
- gimple_init_edge_profiler ();
+ gimple_init_gcov_profiler ();
/* Insert code:
@@ -460,16 +458,74 @@ gimple_gen_ic_func_profiler (void)
counter position and GSI is the iterator we place the counter. */
void
-gimple_gen_time_profiler (unsigned tag, unsigned base,
- gimple_stmt_iterator &gsi)
+gimple_gen_time_profiler (unsigned tag, unsigned base)
{
- tree ref_ptr = tree_coverage_counter_addr (tag, base);
- gcall *call;
+ tree type = get_gcov_type ();
+ basic_block cond_bb
+ = split_edge (single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
+
+ basic_block update_bb = split_edge (single_succ_edge (cond_bb));
+
+ edge true_edge = single_succ_edge (cond_bb);
+ true_edge->flags = EDGE_TRUE_VALUE;
+ true_edge->probability = PROB_VERY_UNLIKELY;
+ edge e
+ = make_edge (cond_bb, single_succ_edge (update_bb)->dest, EDGE_FALSE_VALUE);
+ e->probability = REG_BR_PROB_BASE - true_edge->probability;
+
+ gimple_stmt_iterator gsi = gsi_start_bb (cond_bb);
+ tree original_ref = tree_coverage_counter_ref (tag, base);
+ tree ref = force_gimple_operand_gsi (&gsi, original_ref, true, NULL_TREE,
+ true, GSI_SAME_STMT);
+ tree one = build_int_cst (type, 1);
- ref_ptr = force_gimple_operand_gsi (&gsi, ref_ptr,
- true, NULL_TREE, true, GSI_SAME_STMT);
- call = gimple_build_call (tree_time_profiler_fn, 1, ref_ptr);
- gsi_insert_before (&gsi, call, GSI_NEW_STMT);
+ /* Emit: if (counters[0] != 0). */
+ gcond *cond = gimple_build_cond (EQ_EXPR, ref, build_int_cst (type, 0),
+ NULL, NULL);
+ gsi_insert_before (&gsi, cond, GSI_NEW_STMT);
+
+ gsi = gsi_start_bb (update_bb);
+
+ /* Emit: counters[0] = ++__gcov_time_profiler_counter. */
+ if (flag_profile_update == PROFILE_UPDATE_ATOMIC)
+ {
+ tree ptr = make_temp_ssa_name (type, NULL, "time_profiler_counter_ptr");
+ tree addr = build1 (ADDR_EXPR, build_pointer_type (type),
+ tree_time_profiler_counter);
+ gassign *assign = gimple_build_assign (ptr, NOP_EXPR, addr);
+ gsi_insert_before (&gsi, assign, GSI_NEW_STMT);
+ tree f = builtin_decl_explicit (LONG_LONG_TYPE_SIZE > 32
+ ? BUILT_IN_ATOMIC_ADD_FETCH_8:
+ BUILT_IN_ATOMIC_ADD_FETCH_4);
+ gcall *stmt = gimple_build_call (f, 3, ptr, one,
+ build_int_cst (integer_type_node,
+ MEMMODEL_RELAXED));
+ tree result_type = TREE_TYPE (TREE_TYPE (f));
+ tree tmp = make_temp_ssa_name (result_type, NULL, "time_profile");
+ gimple_set_lhs (stmt, tmp);
+ gsi_insert_after (&gsi, stmt, GSI_NEW_STMT);
+ tmp = make_temp_ssa_name (type, NULL, "time_profile");
+ assign = gimple_build_assign (tmp, NOP_EXPR,
+ gimple_call_lhs (stmt));
+ gsi_insert_after (&gsi, assign, GSI_NEW_STMT);
+ assign = gimple_build_assign (original_ref, tmp);
+ gsi_insert_after (&gsi, assign, GSI_NEW_STMT);
+ }
+ else
+ {
+ tree tmp = make_temp_ssa_name (type, NULL, "time_profile");
+ gassign *assign = gimple_build_assign (tmp, tree_time_profiler_counter);
+ gsi_insert_before (&gsi, assign, GSI_NEW_STMT);
+
+ tmp = make_temp_ssa_name (type, NULL, "time_profile");
+ assign = gimple_build_assign (tmp, PLUS_EXPR, gimple_assign_lhs (assign),
+ one);
+ gsi_insert_after (&gsi, assign, GSI_NEW_STMT);
+ assign = gimple_build_assign (original_ref, tmp);
+ gsi_insert_after (&gsi, assign, GSI_NEW_STMT);
+ assign = gimple_build_assign (tree_time_profiler_counter, tmp);
+ gsi_insert_after (&gsi, assign, GSI_NEW_STMT);
+ }
}
/* Output instructions as GIMPLE trees to increment the average histogram
@@ -96,15 +96,14 @@ bool check_ic_target (gcall *, struct cgraph_node *);
/* In tree-profile.c. */
-extern void gimple_init_edge_profiler (void);
+extern void gimple_init_gcov_profiler (void);
extern void gimple_gen_edge_profiler (int, edge);
extern void gimple_gen_interval_profiler (histogram_value, unsigned, unsigned);
extern void gimple_gen_pow2_profiler (histogram_value, unsigned, unsigned);
extern void gimple_gen_one_value_profiler (histogram_value, unsigned, unsigned);
extern void gimple_gen_ic_profiler (histogram_value, unsigned, unsigned);
extern void gimple_gen_ic_func_profiler (void);
-extern void gimple_gen_time_profiler (unsigned, unsigned,
- gimple_stmt_iterator &);
+extern void gimple_gen_time_profiler (unsigned, unsigned);
extern void gimple_gen_average_profiler (histogram_value, unsigned, unsigned);
extern void gimple_gen_ior_profiler (histogram_value, unsigned, unsigned);
extern void stream_out_histogram_value (struct output_block *, histogram_value);
@@ -342,30 +342,9 @@ __gcov_indirect_call_profiler_v2 (gcov_type value, void* cur_func)
#ifdef L_gcov_time_profiler
/* Counter for first visit of each function. */
-static gcov_type function_counter;
+gcov_type __gcov_time_profiler_counter ATTRIBUTE_HIDDEN;
-/* Sets corresponding COUNTERS if there is no value. */
-
-void
-__gcov_time_profiler (gcov_type* counters)
-{
- if (!counters[0])
- counters[0] = ++function_counter;
-}
-
-#if GCOV_SUPPORTS_ATOMIC
-/* Sets corresponding COUNTERS if there is no value.
- Function is thread-safe. */
-
-void
-__gcov_time_profiler_atomic (gcov_type* counters)
-{
- if (!counters[0])
- counters[0] = __atomic_add_fetch (&function_counter, 1, __ATOMIC_RELAXED);
-}
#endif
-#endif
-
#ifdef L_gcov_average_profiler
/* Increase corresponding COUNTER by VALUE. FIXME: Perhaps we want
--
2.10.1
Hello. As Honza noticed we spent quite some time in __gcov_time_profiler: perf report for Postgres make check command: 4.10% postgres postgres[.]__gcov_time_profiler Thus I rewrote the profiling code directly to GIMPLE statements: _4 = __gcov7.main[0]; if (_4 == 0) goto <bb 3>; else goto <bb 4>; <bb 3>: time_profile_5 = __gcov_time_profiler_counter; time_profile_6 = time_profile_5 + 1; __gcov7.main[0] = time_profile_6; __gcov_time_profiler_counter = time_profile_6; thread-safe variant of the patch: _3 = __gcov7.foo[0]; if (_3 == 0) goto <bb 3>; else goto <bb 4>; <bb 3>: time_profiler_counter_ptr_4 = (long int) &__gcov_time_profiler_counter; time_profile_5 = __atomic_add_fetch_8 (time_profiler_counter_ptr_4, 1, 0); time_profile_6 = (long int) time_profile_5; __gcov7.foo[0] = time_profile_6; Patch can bootstrap on ppc64le-redhat-linux and survives regression tests. Ready to be installed? Martin