On 13 June 2016 at 16:13, Jan Hubicka <hubi...@ucw.cz> wrote:
>> diff --git a/gcc/cgraph.h b/gcc/cgraph.h
>> index ecafe63..41ac408 100644
>> --- a/gcc/cgraph.h
>> +++ b/gcc/cgraph.h
>> @@ -1874,6 +1874,9 @@ public:
>> if we did not do any inter-procedural code movement. */
>> unsigned used_by_single_function : 1;
>>
>> + /* Set if -fsection-anchors is set. */
>> + unsigned section_anchor : 1;
>> +
>> private:
>> /* Assemble thunks and aliases associated to varpool node. */
>> void assemble_aliases (void);
>> diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
>> index 4bfcad7..e75d5c0 100644
>> --- a/gcc/cgraphunit.c
>> +++ b/gcc/cgraphunit.c
>> @@ -800,6 +800,9 @@ varpool_node::finalize_decl (tree decl)
>> it is available to notice_global_symbol. */
>> node->definition = true;
>> notice_global_symbol (decl);
>> +
>> + node->section_anchor = flag_section_anchors;
>> +
>> if (TREE_THIS_VOLATILE (decl) || DECL_PRESERVE_P (decl)
>> /* Traditionally we do not eliminate static variables when not
>> optimizing and when not doing toplevel reoder. */
>> diff --git a/gcc/common.opt b/gcc/common.opt
>> index f0d7196..e497795 100644
>> --- a/gcc/common.opt
>> +++ b/gcc/common.opt
>> @@ -1590,6 +1590,10 @@ fira-algorithm=
>> Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm)
>> Init(IRA_ALGORITHM_CB) Optimization
>> -fira-algorithm=[CB|priority] Set the used IRA algorithm.
>>
>> +fipa-increase_alignment
>> +Common Report Var(flag_ipa_increase_alignment) Init(0) Optimization
>> +Option to gate increase_alignment ipa pass.
>> +
>> Enum
>> Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA
>> algorithm %qs)
>>
>> @@ -2133,7 +2137,7 @@ Common Report Var(flag_sched_dep_count_heuristic)
>> Init(1) Optimization
>> Enable the dependent count heuristic in the scheduler.
>>
>> fsection-anchors
>> -Common Report Var(flag_section_anchors) Optimization
>> +Common Report Var(flag_section_anchors)
>> Access data in the same section from shared anchor points.
>>
>> fsee
>> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
>> index a0db3a4..1482566 100644
>> --- a/gcc/config/aarch64/aarch64.c
>> +++ b/gcc/config/aarch64/aarch64.c
>> @@ -8252,6 +8252,8 @@ aarch64_override_options (void)
>>
>> aarch64_register_fma_steering ();
>>
>> + /* Enable increase_alignment pass. */
>> + flag_ipa_increase_alignment = 1;
>
> I would rather enable it always on targets that do support anchors.
AFAIK aarch64 supports section anchors.
>> diff --git a/gcc/lto/lto-symtab.c b/gcc/lto/lto-symtab.c
>> index ce9e146..7f09f3a 100644
>> --- a/gcc/lto/lto-symtab.c
>> +++ b/gcc/lto/lto-symtab.c
>> @@ -342,6 +342,13 @@ lto_symtab_merge (symtab_node *prevailing, symtab_node
>> *entry)
>> The type compatibility checks or the completing of types has properly
>> dealt with most issues. */
>>
>> + /* ??? is this assert necessary ? */
>> + varpool_node *v_prevailing = dyn_cast<varpool_node *> (prevailing);
>> + varpool_node *v_entry = dyn_cast<varpool_node *> (entry);
>> + gcc_assert (v_prevailing && v_entry);
>> + /* section_anchor of prevailing_decl wins. */
>> + v_entry->section_anchor = v_prevailing->section_anchor;
>> +
> Other flags are merged in lto_varpool_replace_node so please move this there.
Ah indeed, thanks for the pointers.
I wonder though if we need to set
prevailing_node->section_anchor = vnode->section_anchor ?
IIUC, the function merges flags from vnode into prevailing_node
and removes vnode. However we want prevailing_node->section_anchor
to always take precedence.
>> +/* Return true if alignment should be increased for this vnode.
>> + This is done if every function that references/referring to vnode
>> + has flag_tree_loop_vectorize set. */
>> +
>> +static bool
>> +increase_alignment_p (varpool_node *vnode)
>> +{
>> + ipa_ref *ref;
>> +
>> + for (int i = 0; vnode->iterate_reference (i, ref); i++)
>> + if (cgraph_node *cnode = dyn_cast<cgraph_node *> (ref->referred))
>> + {
>> + struct cl_optimization *opts = opts_for_fn (cnode->decl);
>> + if (!opts->x_flag_tree_loop_vectorize)
>> + return false;
>> + }
>
> If you take address of function that has vectorizer enabled probably doesn't
> imply need to increase alignment of that var. So please drop the loop.
>
> You only want function that read/writes or takes address of the symbol. But
> onthe other hand, you need to walk all aliases of the symbol by
> call_for_symbol_and_aliases
>> +
>> + for (int i = 0; vnode->iterate_referring (i, ref); i++)
>> + if (cgraph_node *cnode = dyn_cast<cgraph_node *> (ref->referring))
>> + {
>> + struct cl_optimization *opts = opts_for_fn (cnode->decl);
>> + if (!opts->x_flag_tree_loop_vectorize)
>> + return false;
>> + }
>> +
>> + return true;
>> +}
>> +
>> /* Entry point to increase_alignment pass. */
>> static unsigned int
>> increase_alignment (void)
>> @@ -914,9 +942,12 @@ increase_alignment (void)
>> tree decl = vnode->decl;
>> unsigned int alignment;
>>
>> - if ((decl_in_symtab_p (decl)
>> - && !symtab_node::get (decl)->can_increase_alignment_p ())
>> - || DECL_USER_ALIGN (decl) || DECL_ARTIFICIAL (decl))
>> + if (!vnode->section_anchor
>> + || (decl_in_symtab_p (decl)
>> + && !symtab_node::get (decl)->can_increase_alignment_p ())
>> + || DECL_USER_ALIGN (decl)
>> + || DECL_ARTIFICIAL (decl)
>> + || !increase_alignment_p (vnode))
>
> Incrementally we probably should do more testing whether the variable looks
> like
> someting that can be vectorized, i.e. it contains array, has address taken or
> the
> accesses are array accesses within loop.
> This can be done by the analysis phase of the IPA pass inspecting the function
> bodies.
Thanks, I will try to check for array accesses are within a loop in
followup patch.
I was wondering if we could we treat a homogeneous global struct
(having members of one type),
as a global array of that type and increase it's alignment if required ?
>
> I think it is important waste to bump up everything including error messages
> etc.
> At least on i386 the effect on firefox datasegment of various alignment
> setting is
> very visible.
Um for a start, would it be OK to check if all functions referencing variable
have attribute noreturn, and in that case we skip increasing the alignment ?
I suppose that error functions would be having attribute noreturn set ?
>
> Looks OK to me otherwise. please send updated patch.
I have done the changes in the attached patch (stage-1 built).
I am not sure what to return from the callback function and
arbitrarily chose to return true.
Thanks,
Prathamesh
>
> Honza
diff --git a/gcc/cgraph.h b/gcc/cgraph.h
index ecafe63..41ac408 100644
--- a/gcc/cgraph.h
+++ b/gcc/cgraph.h
@@ -1874,6 +1874,9 @@ public:
if we did not do any inter-procedural code movement. */
unsigned used_by_single_function : 1;
+ /* Set if -fsection-anchors is set. */
+ unsigned section_anchor : 1;
+
private:
/* Assemble thunks and aliases associated to varpool node. */
void assemble_aliases (void);
diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
index 4bfcad7..e75d5c0 100644
--- a/gcc/cgraphunit.c
+++ b/gcc/cgraphunit.c
@@ -800,6 +800,9 @@ varpool_node::finalize_decl (tree decl)
it is available to notice_global_symbol. */
node->definition = true;
notice_global_symbol (decl);
+
+ node->section_anchor = flag_section_anchors;
+
if (TREE_THIS_VOLATILE (decl) || DECL_PRESERVE_P (decl)
/* Traditionally we do not eliminate static variables when not
optimizing and when not doing toplevel reoder. */
diff --git a/gcc/common.opt b/gcc/common.opt
index f0d7196..e497795 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -1590,6 +1590,10 @@ fira-algorithm=
Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm)
Init(IRA_ALGORITHM_CB) Optimization
-fira-algorithm=[CB|priority] Set the used IRA algorithm.
+fipa-increase_alignment
+Common Report Var(flag_ipa_increase_alignment) Init(0) Optimization
+Option to gate increase_alignment ipa pass.
+
Enum
Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA
algorithm %qs)
@@ -2133,7 +2137,7 @@ Common Report Var(flag_sched_dep_count_heuristic) Init(1)
Optimization
Enable the dependent count heuristic in the scheduler.
fsection-anchors
-Common Report Var(flag_section_anchors) Optimization
+Common Report Var(flag_section_anchors)
Access data in the same section from shared anchor points.
fsee
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index a0db3a4..1482566 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -8252,6 +8252,8 @@ aarch64_override_options (void)
aarch64_register_fma_steering ();
+ /* Enable increase_alignment pass. */
+ flag_ipa_increase_alignment = 1;
}
/* Implement targetm.override_options_after_change. */
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 3503c15..b7f448e 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -3458,6 +3458,9 @@ arm_option_override (void)
/* Init initial mode for testing. */
thumb_flipper = TARGET_THUMB;
+
+ /* Enable increase_alignment pass. */
+ flag_ipa_increase_alignment = 1;
}
static void
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 2d7df6b..ed59068 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -5011,6 +5011,9 @@ rs6000_option_override (void)
= { pass_analyze_swaps, "cse1", 1, PASS_POS_INSERT_BEFORE };
register_pass (&analyze_swaps_info);
+
+ /* Enable increase_alignment pass. */
+ flag_ipa_increase_alignment = 1;
}
diff --git a/gcc/lto-cgraph.c b/gcc/lto-cgraph.c
index 5cef2ba..289d9c3 100644
--- a/gcc/lto-cgraph.c
+++ b/gcc/lto-cgraph.c
@@ -627,6 +627,7 @@ lto_output_varpool_node (struct lto_simple_output_block
*ob, varpool_node *node,
bp_pack_value (&bp, node->tls_model, 3);
bp_pack_value (&bp, node->used_by_single_function, 1);
bp_pack_value (&bp, node->need_bounds_init, 1);
+ bp_pack_value (&bp, node->section_anchor, 1);
streamer_write_bitpack (&bp);
group = node->get_comdat_group ();
@@ -1401,6 +1402,7 @@ input_varpool_node (struct lto_file_decl_data *file_data,
node->tls_model = (enum tls_model)bp_unpack_value (&bp, 3);
node->used_by_single_function = (enum tls_model)bp_unpack_value (&bp, 1);
node->need_bounds_init = bp_unpack_value (&bp, 1);
+ node->section_anchor = bp_unpack_value (&bp, 1);
group = read_identifier (ib);
if (group)
{
diff --git a/gcc/passes.def b/gcc/passes.def
index 3647e90..3a8063c 100644
--- a/gcc/passes.def
+++ b/gcc/passes.def
@@ -138,12 +138,12 @@ along with GCC; see the file COPYING3. If not see
PUSH_INSERT_PASSES_WITHIN (pass_ipa_tree_profile)
NEXT_PASS (pass_feedback_split_functions);
POP_INSERT_PASSES ()
- NEXT_PASS (pass_ipa_increase_alignment);
NEXT_PASS (pass_ipa_tm);
NEXT_PASS (pass_ipa_lower_emutls);
TERMINATE_PASS_LIST (all_small_ipa_passes)
INSERT_PASSES_AFTER (all_regular_ipa_passes)
+ NEXT_PASS (pass_ipa_increase_alignment);
NEXT_PASS (pass_ipa_whole_program_visibility);
NEXT_PASS (pass_ipa_profile);
NEXT_PASS (pass_ipa_icf);
diff --git a/gcc/testsuite/gcc.dg/vect/aligned-section-anchors-vect-73.c
b/gcc/testsuite/gcc.dg/vect/aligned-section-anchors-vect-73.c
new file mode 100644
index 0000000..74eaed8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/aligned-section-anchors-vect-73.c
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target section_anchors } */
+/* { dg-require-effective-target vect_int } */
+
+#define N 32
+
+/* Clone of section-anchors-vect-70.c with foo() having
-fno-tree-loop-vectorize. */
+
+static struct A {
+ int p1, p2;
+ int e[N];
+} a, b, c;
+
+__attribute__((optimize("-fno-tree-loop-vectorize")))
+int foo(void)
+{
+ for (int i = 0; i < N; i++)
+ a.e[i] = b.e[i] + c.e[i];
+
+ return a.e[0];
+}
+
+/* { dg-final { scan-ipa-dump-times "Increasing alignment of decl" 0
"increase_alignment" { target aarch64*-*-* } } } */
+/* { dg-final { scan-ipa-dump-times "Increasing alignment of decl" 0
"increase_alignment" { target powerpc64*-*-* } } } */
+/* { dg-final { scan-ipa-dump-times "Increasing alignment of decl" 0
"increase_alignment" { target arm*-*-* } } } */
diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
index 36299a6..d36aa1d 100644
--- a/gcc/tree-pass.h
+++ b/gcc/tree-pass.h
@@ -483,7 +483,7 @@ extern simple_ipa_opt_pass
*make_pass_local_optimization_passes (gcc::context *c
extern ipa_opt_pass_d *make_pass_ipa_whole_program_visibility (gcc::context
*ctxt);
-extern simple_ipa_opt_pass *make_pass_ipa_increase_alignment (gcc::context
+extern ipa_opt_pass_d *make_pass_ipa_increase_alignment (gcc::context
*ctxt);
extern ipa_opt_pass_d *make_pass_ipa_inline (gcc::context *ctxt);
extern simple_ipa_opt_pass *make_pass_ipa_free_lang_data (gcc::context *ctxt);
diff --git a/gcc/tree-vectorizer.c b/gcc/tree-vectorizer.c
index 2669813..c693950 100644
--- a/gcc/tree-vectorizer.c
+++ b/gcc/tree-vectorizer.c
@@ -899,6 +899,55 @@ get_vec_alignment_for_type (tree type)
return (alignment > TYPE_ALIGN (type)) ? alignment : 0;
}
+/* Return true if alignment should be increased for this vnode.
+ This is done if every function that referring to vnode
+ has flag_tree_loop_vectorize set. */
+
+static bool
+increase_alignment_p (varpool_node *vnode)
+{
+ ipa_ref *ref;
+ cgraph_node *cnode;
+
+ for (int i = 0; vnode->iterate_referring (i, ref); i++)
+ /* Walk those functions that read/write/take address of vnode. */
+ if ((cnode = dyn_cast<cgraph_node *> (ref->referring))
+ && (ref->use == IPA_REF_LOAD || ref->use == IPA_REF_STORE || ref->use
== IPA_REF_ADDR))
+ {
+ struct cl_optimization *opts = opts_for_fn (cnode->decl);
+ if (!opts->x_flag_tree_loop_vectorize)
+ return false;
+ }
+
+ return true;
+}
+
+static bool
+increase_alignment_callback (varpool_node *vnode, void *data ATTRIBUTE_UNUSED)
+{
+ tree decl = vnode->decl;
+
+ if (!vnode->section_anchor
+ || (decl_in_symtab_p (decl)
+ && !symtab_node::get (decl)->can_increase_alignment_p ())
+ || DECL_USER_ALIGN (decl)
+ || DECL_ARTIFICIAL (decl)
+ || !increase_alignment_p (vnode))
+ return true;
+
+ unsigned alignment = get_vec_alignment_for_type (TREE_TYPE (decl));
+ if (alignment && vect_can_force_dr_alignment_p (decl, alignment))
+ {
+ vnode->increase_alignment (alignment);
+ dump_printf (MSG_NOTE, "Increasing alignment of decl: ");
+ dump_generic_expr (MSG_NOTE, TDF_SLIM, decl);
+ dump_printf (MSG_NOTE, "\n");
+ return true;
+ }
+
+ return true;
+}
+
/* Entry point to increase_alignment pass. */
static unsigned int
increase_alignment (void)
@@ -910,24 +959,7 @@ increase_alignment (void)
/* Increase the alignment of all global arrays for vectorization. */
FOR_EACH_DEFINED_VARIABLE (vnode)
- {
- tree decl = vnode->decl;
- unsigned int alignment;
-
- if ((decl_in_symtab_p (decl)
- && !symtab_node::get (decl)->can_increase_alignment_p ())
- || DECL_USER_ALIGN (decl) || DECL_ARTIFICIAL (decl))
- continue;
-
- alignment = get_vec_alignment_for_type (TREE_TYPE (decl));
- if (alignment && vect_can_force_dr_alignment_p (decl, alignment))
- {
- vnode->increase_alignment (alignment);
- dump_printf (MSG_NOTE, "Increasing alignment of decl: ");
- dump_generic_expr (MSG_NOTE, TDF_SLIM, decl);
- dump_printf (MSG_NOTE, "\n");
- }
- }
+ vnode->call_for_symbol_and_aliases (increase_alignment_callback, NULL,
true);
delete type_align_map;
return 0;
@@ -938,7 +970,7 @@ namespace {
const pass_data pass_data_ipa_increase_alignment =
{
- SIMPLE_IPA_PASS, /* type */
+ IPA_PASS, /* type */
"increase_alignment", /* name */
OPTGROUP_LOOP | OPTGROUP_VEC, /* optinfo_flags */
TV_IPA_OPT, /* tv_id */
@@ -949,17 +981,26 @@ const pass_data pass_data_ipa_increase_alignment =
0, /* todo_flags_finish */
};
-class pass_ipa_increase_alignment : public simple_ipa_opt_pass
+class pass_ipa_increase_alignment : public ipa_opt_pass_d
{
public:
pass_ipa_increase_alignment (gcc::context *ctxt)
- : simple_ipa_opt_pass (pass_data_ipa_increase_alignment, ctxt)
+ : ipa_opt_pass_d (pass_data_ipa_increase_alignment, ctxt,
+ NULL, /* generate_summary */
+ NULL, /* write summary */
+ NULL, /* read summary */
+ NULL, /* write optimization summary */
+ NULL, /* read optimization summary */
+ NULL, /* stmt fixup */
+ 0, /* function_transform_todo_flags_start */
+ NULL, /* transform function */
+ NULL )/* variable transform */
{}
/* opt_pass methods: */
virtual bool gate (function *)
{
- return flag_section_anchors && flag_tree_loop_vectorize;
+ return flag_ipa_increase_alignment != 0;
}
virtual unsigned int execute (function *) { return increase_alignment (); }
@@ -968,7 +1009,7 @@ public:
} // anon namespace
-simple_ipa_opt_pass *
+ipa_opt_pass_d *
make_pass_ipa_increase_alignment (gcc::context *ctxt)
{
return new pass_ipa_increase_alignment (ctxt);
