Avid ggc_alloc and push_cfun during LTO streaming
Jan Hubicka
hubicka@ucw.cz
Fri Oct 11 09:05:00 GMT 2019
Hi,
this patch prevents tree creation druing WPA stream out (to avoid
touching pages and triggering COW). It fixes the following
- gimple streamer produces MEM_REF wrappings for global decls.
This is to preserve the type of access and is not necessary for
WPA->LTRANS streaming when decls ar eno longer going to be merged.
- we renumber stmt uids during streaming WPA summaries
- loop optimizer is initialized in output_function.
After testing the patch I noticed that output_function does one extra
renumbering of stmts. This seems quite broken and I will fix it
incrementally.
Bootstrapped/regtested x86_64-linux, comitted.
* gimple-streamer-out.c (output_gimple_stmt): Add explicit function
parameter.
* lto-streamer-out.c: Include tree-dfa.h.
(output_cfg): Do not use cfun.
(lto_prepare_function_for_streaming): New.
(output_function): Do not push cfun; do not initialize loop optimizer.
* lto-streamer.h (lto_prepare_function_for_streaming): Declare.
* passes.c (ipa_write_summaries): Use it.
(ipa_write_optimization_summaries): Do not modify bodies.
* tree-dfa.c (renumber_gimple_stmt_uids): Add function parameter.
* tree.dfa.h (renumber_gimple_stmt_uids): Update prototype.
* tree-ssa-dse.c (pass_dse::execute): Update use of
renumber_gimple_stmt_uids.
* tree-ssa-math-opts.c (pass_optimize_widening_mul::execute): Likewise.
* lto.c (lto_wpa_write_files): Prepare all bodies for streaming.
Index: gimple-streamer-out.c
===================================================================
--- gimple-streamer-out.c (revision 276850)
+++ gimple-streamer-out.c (working copy)
@@ -57,7 +57,7 @@ output_phi (struct output_block *ob, gph
/* Emit statement STMT on the main stream of output block OB. */
static void
-output_gimple_stmt (struct output_block *ob, gimple *stmt)
+output_gimple_stmt (struct output_block *ob, struct function *fn, gimple *stmt)
{
unsigned i;
enum gimple_code code;
@@ -80,7 +80,7 @@ output_gimple_stmt (struct output_block
as_a <gassign *> (stmt)),
1);
bp_pack_value (&bp, gimple_has_volatile_ops (stmt), 1);
- hist = gimple_histogram_value (cfun, stmt);
+ hist = gimple_histogram_value (fn, stmt);
bp_pack_value (&bp, hist != NULL, 1);
bp_pack_var_len_unsigned (&bp, stmt->subcode);
@@ -139,7 +139,7 @@ output_gimple_stmt (struct output_block
so that we do not have to deal with type mismatches on
merged symbols during IL read in. The first operand
of GIMPLE_DEBUG must be a decl, not MEM_REF, though. */
- if (op && (i || !is_gimple_debug (stmt)))
+ if (!flag_wpa && op && (i || !is_gimple_debug (stmt)))
{
basep = &op;
if (TREE_CODE (*basep) == ADDR_EXPR)
@@ -147,7 +147,7 @@ output_gimple_stmt (struct output_block
while (handled_component_p (*basep))
basep = &TREE_OPERAND (*basep, 0);
if (VAR_P (*basep)
- && !auto_var_in_fn_p (*basep, current_function_decl)
+ && !auto_var_in_fn_p (*basep, fn->decl)
&& !DECL_REGISTER (*basep))
{
bool volatilep = TREE_THIS_VOLATILE (*basep);
@@ -228,7 +228,7 @@ output_bb (struct output_block *ob, basi
print_gimple_stmt (streamer_dump_file, stmt, 0, TDF_SLIM);
}
- output_gimple_stmt (ob, stmt);
+ output_gimple_stmt (ob, fn, stmt);
/* Emit the EH region holding STMT. */
region = lookup_stmt_eh_lp_fn (fn, stmt);
Index: lto/lto.c
===================================================================
--- lto/lto.c (revision 276850)
+++ lto/lto.c (working copy)
@@ -304,6 +304,13 @@ lto_wpa_write_files (void)
timevar_push (TV_WHOPR_WPA_IO);
+ cgraph_node *node;
+ /* Do body modifications needed for streaming before we fork out
+ worker processes. */
+ FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node)
+ if (gimple_has_body_p (node->decl))
+ lto_prepare_function_for_streaming (node);
+
/* Generate a prefix for the LTRANS unit files. */
blen = strlen (ltrans_output_list);
temp_filename = (char *) xmalloc (blen + sizeof ("2147483648.o"));
Index: lto-streamer-out.c
===================================================================
--- lto-streamer-out.c (revision 276850)
+++ lto-streamer-out.c (working copy)
@@ -43,6 +43,7 @@ along with GCC; see the file COPYING3.
#include "debug.h"
#include "omp-offload.h"
#include "print-tree.h"
+#include "tree-dfa.h"
static void lto_write_tree (struct output_block*, tree, bool);
@@ -1893,7 +1894,7 @@ output_cfg (struct output_block *ob, str
streamer_write_hwi (ob, -1);
- bb = ENTRY_BLOCK_PTR_FOR_FN (cfun);
+ bb = ENTRY_BLOCK_PTR_FOR_FN (fn);
while (bb->next_bb)
{
streamer_write_hwi (ob, bb->next_bb->index);
@@ -1902,9 +1903,6 @@ output_cfg (struct output_block *ob, str
streamer_write_hwi (ob, -1);
- /* ??? The cfgloop interface is tied to cfun. */
- gcc_assert (cfun == fn);
-
/* Output the number of loops. */
streamer_write_uhwi (ob, number_of_loops (fn));
@@ -2062,6 +2060,22 @@ collect_block_tree_leafs (tree root, vec
collect_block_tree_leafs (BLOCK_SUBBLOCKS (root), leafs);
}
+/* This performs function body modifications that are needed for streaming
+ to work. */
+
+void
+lto_prepare_function_for_streaming (struct cgraph_node *node)
+{
+ if (number_of_loops (DECL_STRUCT_FUNCTION (node->decl)))
+ {
+ push_cfun (DECL_STRUCT_FUNCTION (node->decl));
+ loop_optimizer_init (AVOID_CFG_MODIFICATIONS);
+ loop_optimizer_finalize ();
+ pop_cfun ();
+ }
+ renumber_gimple_stmt_uids (DECL_STRUCT_FUNCTION (node->decl));
+}
+
/* Output the body of function NODE->DECL. */
static void
@@ -2085,9 +2099,6 @@ output_function (struct cgraph_node *nod
gcc_assert (current_function_decl == NULL_TREE && cfun == NULL);
- /* Set current_function_decl and cfun. */
- push_cfun (fn);
-
/* Make string 0 be a NULL string. */
streamer_write_char_stream (ob->string_stream, 0);
@@ -2124,9 +2135,6 @@ output_function (struct cgraph_node *nod
debug info. */
if (gimple_has_body_p (function))
{
- /* Fixup loops if required to match discovery done in the reader. */
- loop_optimizer_init (AVOID_CFG_MODIFICATIONS);
-
streamer_write_uhwi (ob, 1);
output_struct_function_base (ob, fn);
@@ -2143,8 +2151,8 @@ output_function (struct cgraph_node *nod
statement numbers. We do not assign UIDs to PHIs here because
virtual PHIs get re-computed on-the-fly which would make numbers
inconsistent. */
- set_gimple_stmt_max_uid (cfun, 0);
- FOR_ALL_BB_FN (bb, cfun)
+ set_gimple_stmt_max_uid (fn, 0);
+ FOR_ALL_BB_FN (bb, fn)
{
for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi);
gsi_next (&gsi))
@@ -2153,25 +2161,25 @@ output_function (struct cgraph_node *nod
/* Virtual PHIs are not going to be streamed. */
if (!virtual_operand_p (gimple_phi_result (stmt)))
- gimple_set_uid (stmt, inc_gimple_stmt_max_uid (cfun));
+ gimple_set_uid (stmt, inc_gimple_stmt_max_uid (fn));
}
for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi);
gsi_next (&gsi))
{
gimple *stmt = gsi_stmt (gsi);
- gimple_set_uid (stmt, inc_gimple_stmt_max_uid (cfun));
+ gimple_set_uid (stmt, inc_gimple_stmt_max_uid (fn));
}
}
/* To avoid keeping duplicate gimple IDs in the statements, renumber
virtual phis now. */
- FOR_ALL_BB_FN (bb, cfun)
+ FOR_ALL_BB_FN (bb, fn)
{
for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi);
gsi_next (&gsi))
{
gphi *stmt = gsi.phi ();
if (virtual_operand_p (gimple_phi_result (stmt)))
- gimple_set_uid (stmt, inc_gimple_stmt_max_uid (cfun));
+ gimple_set_uid (stmt, inc_gimple_stmt_max_uid (fn));
}
}
@@ -2183,9 +2191,6 @@ output_function (struct cgraph_node *nod
streamer_write_record_start (ob, LTO_null);
output_cfg (ob, fn);
-
- loop_optimizer_finalize ();
- pop_cfun ();
}
else
streamer_write_uhwi (ob, 0);
Index: lto-streamer.h
===================================================================
--- lto-streamer.h (revision 276850)
+++ lto-streamer.h (working copy)
@@ -909,6 +909,7 @@ void lto_output_decl_state_refs (struct
struct lto_out_decl_state *);
void lto_output_location (struct output_block *, struct bitpack_d *, location_t);
void lto_output_init_mode_table (void);
+void lto_prepare_function_for_streaming (cgraph_node *);
/* In lto-cgraph.c */
Index: passes.c
===================================================================
--- passes.c (revision 276850)
+++ passes.c (working copy)
@@ -2705,20 +2705,12 @@ ipa_write_summaries (void)
{
struct cgraph_node *node = order[i];
- if (gimple_has_body_p (node->decl))
+ if (node->definition && node->need_lto_streaming)
{
- /* When streaming out references to statements as part of some IPA
- pass summary, the statements need to have uids assigned and the
- following does that for all the IPA passes here. Naturally, this
- ordering then matches the one IPA-passes get in their stmt_fixup
- hooks. */
-
- push_cfun (DECL_STRUCT_FUNCTION (node->decl));
- renumber_gimple_stmt_uids ();
- pop_cfun ();
+ if (gimple_has_body_p (node->decl))
+ lto_prepare_function_for_streaming (node);
+ lto_set_symtab_encoder_in_partition (encoder, node);
}
- if (node->definition && node->need_lto_streaming)
- lto_set_symtab_encoder_in_partition (encoder, node);
}
FOR_EACH_DEFINED_FUNCTION (node)
@@ -2786,28 +2778,13 @@ void
ipa_write_optimization_summaries (lto_symtab_encoder_t encoder)
{
struct lto_out_decl_state *state = lto_new_out_decl_state ();
- lto_symtab_encoder_iterator lsei;
state->symtab_node_encoder = encoder;
lto_output_init_mode_table ();
lto_push_out_decl_state (state);
- for (lsei = lsei_start_function_in_partition (encoder);
- !lsei_end_p (lsei); lsei_next_function_in_partition (&lsei))
- {
- struct cgraph_node *node = lsei_cgraph_node (lsei);
- /* When streaming out references to statements as part of some IPA
- pass summary, the statements need to have uids assigned.
-
- For functions newly born at WPA stage we need to initialize
- the uids here. */
- if (node->definition
- && gimple_has_body_p (node->decl))
- {
- push_cfun (DECL_STRUCT_FUNCTION (node->decl));
- renumber_gimple_stmt_uids ();
- pop_cfun ();
- }
- }
+
+ /* Be sure that we did not forget to renumber stmt uids. */
+ gcc_checking_assert (flag_wpa);
gcc_assert (flag_wpa);
pass_manager *passes = g->get_passes ();
Index: tree-dfa.c
===================================================================
--- tree-dfa.c (revision 276850)
+++ tree-dfa.c (working copy)
@@ -61,23 +61,23 @@ static void collect_dfa_stats (struct df
/* Renumber all of the gimple stmt uids. */
void
-renumber_gimple_stmt_uids (void)
+renumber_gimple_stmt_uids (struct function *fun)
{
basic_block bb;
- set_gimple_stmt_max_uid (cfun, 0);
- FOR_ALL_BB_FN (bb, cfun)
+ set_gimple_stmt_max_uid (fun, 0);
+ FOR_ALL_BB_FN (bb, fun)
{
gimple_stmt_iterator bsi;
for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi))
{
gimple *stmt = gsi_stmt (bsi);
- gimple_set_uid (stmt, inc_gimple_stmt_max_uid (cfun));
+ gimple_set_uid (stmt, inc_gimple_stmt_max_uid (fun));
}
for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
{
gimple *stmt = gsi_stmt (bsi);
- gimple_set_uid (stmt, inc_gimple_stmt_max_uid (cfun));
+ gimple_set_uid (stmt, inc_gimple_stmt_max_uid (fun));
}
}
}
Index: tree-dfa.h
===================================================================
--- tree-dfa.h (revision 276850)
+++ tree-dfa.h (working copy)
@@ -20,7 +20,7 @@ along with GCC; see the file COPYING3.
#ifndef GCC_TREE_DFA_H
#define GCC_TREE_DFA_H
-extern void renumber_gimple_stmt_uids (void);
+extern void renumber_gimple_stmt_uids (struct function *);
extern void renumber_gimple_stmt_uids_in_blocks (basic_block *, int);
extern void dump_variable (FILE *, tree);
extern void debug_variable (tree);
Index: tree-ssa-dse.c
===================================================================
--- tree-ssa-dse.c (revision 276850)
+++ tree-ssa-dse.c (working copy)
@@ -1113,7 +1113,7 @@ pass_dse::execute (function *fun)
{
need_eh_cleanup = BITMAP_ALLOC (NULL);
- renumber_gimple_stmt_uids ();
+ renumber_gimple_stmt_uids (cfun);
/* We might consider making this a property of each pass so that it
can be [re]computed on an as-needed basis. Particularly since
Index: tree-ssa-math-opts.c
===================================================================
--- tree-ssa-math-opts.c (revision 276850)
+++ tree-ssa-math-opts.c (working copy)
@@ -3850,7 +3850,7 @@ pass_optimize_widening_mul::execute (fun
memset (&widen_mul_stats, 0, sizeof (widen_mul_stats));
calculate_dominance_info (CDI_DOMINATORS);
- renumber_gimple_stmt_uids ();
+ renumber_gimple_stmt_uids (cfun);
math_opts_dom_walker (&cfg_changed).walk (ENTRY_BLOCK_PTR_FOR_FN (cfun));
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