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[PATCH] Fix for PR ipa/64693
- From: Martin LiÅka <mliska at suse dot cz>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Cc: "hubicka >> Jan Hubicka" <hubicka at ucw dot cz>
- Date: Thu, 12 Feb 2015 10:51:33 +0100
- Subject: [PATCH] Fix for PR ipa/64693
- Authentication-results: sourceware.org; auth=none
Hello.
There's patch for aforementioned issue where ICF process a merge operation
for a pair of functions that pass a pointer to the second pair of functions
(these functions are also identical). Unfortunately, these addresses are compared
for equality.
Patch can lto-boostrap on x86_64 and pch.exp tests work correctly.
Ready for trunk?
Thanks,
Martin
>From 7134778d86d85aafc05fc9af9c8a2973516da29c Mon Sep 17 00:00:00 2001
From: mliska <mliska@suse.cz>
Date: Fri, 23 Jan 2015 14:58:36 +0100
Subject: [PATCH] Fix PR ipa/64693.
gcc/ChangeLog:
2015-02-12 Martin Liska <mliska@suse.cz>
PR ipa/64693
* ipa-icf.c (sem_item_optimizer::execute): Call identify_address_sensitive_classes.
(sem_item_optimizer::identify_address_sensitive_classes): New function.
(sem_item_optimizer::merge_classes): Handle cases where we merge a class
with a sensitive reference.
(congruence_class::dump): Add support for a new sensitive_reference flag.
* ipa-icf.h: Add new function.
gcc/testsuite/ChangeLog:
2015-01-23 Martin Liska <mliska@suse.cz>
* gcc.dg/ipa/ipa-icf-26.c: Fix expected results.
* gcc.dg/ipa/ipa-icf-33.c: Remove reduced line.
* gcc.dg/ipa/ipa-icf-34.c: New test.
---
gcc/ipa-icf.c | 71 ++++++++++++++++++++++++++++++++++-
gcc/ipa-icf.h | 10 ++++-
gcc/testsuite/gcc.dg/ipa/ipa-icf-26.c | 2 +-
gcc/testsuite/gcc.dg/ipa/ipa-icf-33.c | 1 -
gcc/testsuite/gcc.dg/ipa/ipa-icf-34.c | 44 ++++++++++++++++++++++
5 files changed, 123 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/ipa/ipa-icf-34.c
diff --git a/gcc/ipa-icf.c b/gcc/ipa-icf.c
index afb5be5..12dd794 100644
--- a/gcc/ipa-icf.c
+++ b/gcc/ipa-icf.c
@@ -1729,6 +1729,7 @@ sem_item_optimizer::execute (void)
unsigned int prev_class_count = m_classes_count;
process_cong_reduction ();
+ identify_address_sensitive_classes ();
dump_cong_classes ();
verify_classes ();
merge_classes (prev_class_count);
@@ -2240,6 +2241,61 @@ sem_item_optimizer::process_cong_reduction (void)
do_congruence_step (cls);
}
+
+/* Identify congruence classes which have an address taken. These
+ classes can be potentially been merged just as thunks. */
+
+void
+sem_item_optimizer::identify_address_sensitive_classes (void)
+{
+ for (hash_table<congruence_class_group_hash>::iterator it = m_classes.begin ();
+ it != m_classes.end (); ++it)
+ for (unsigned i = 0; i < (*it)->classes.length (); i++)
+ {
+ congruence_class *cls = (*it)->classes[i];
+
+ if (cls->members.length () == 1)
+ continue;
+
+ auto_vec <sem_item *> references;
+ sem_item *source_node = cls->members[0];
+ ipa_ref *r;
+
+ for (unsigned j = 0; j < source_node->node->num_references (); j++)
+ {
+ symtab_node *ref = source_node->node->iterate_reference (j, r)->referred;
+ sem_item **symbol = m_symtab_node_map.get (ref);
+ if (symbol)
+ references.safe_push (*symbol);
+ }
+
+ for (unsigned j = 1; j < cls->members.length (); j++)
+ {
+ source_node = cls->members[j];
+
+ unsigned l = 0;
+ for (unsigned k = 0; k < source_node->node->num_references (); k++)
+ {
+ symtab_node *ref = source_node->node->iterate_reference (k, r)->referred;
+ sem_item **symbol = m_symtab_node_map.get (ref);
+ if (symbol)
+ {
+ if (l >= references.length () || references[l] != *symbol)
+ {
+ cls->sensitive_reference = true;
+ break;
+ }
+
+ l++;
+ }
+ }
+
+ if (cls->sensitive_reference)
+ break;
+ }
+ }
+}
+
/* Debug function prints all informations about congruence classes. */
void
@@ -2374,6 +2430,15 @@ sem_item_optimizer::merge_classes (unsigned int prev_class_count)
continue;
}
+ if (c->sensitive_reference)
+ {
+ if (dump_file)
+ fprintf (dump_file, "A function from the congruence class "
+ "uses a sensitive reference.\n");
+
+ continue;
+ }
+
if (dump_file && (dump_flags & TDF_DETAILS))
{
source->dump_to_file (dump_file);
@@ -2390,8 +2455,10 @@ sem_item_optimizer::merge_classes (unsigned int prev_class_count)
void
congruence_class::dump (FILE *file, unsigned int indent) const
{
- FPRINTF_SPACES (file, indent, "class with id: %u, hash: %u, items: %u\n",
- id, members[0]->get_hash (), members.length ());
+ FPRINTF_SPACES (file, indent,
+ "class with id: %u, hash: %u, items: %u %s\n",
+ id, members[0]->get_hash (), members.length (),
+ sensitive_reference ? "sensitive_reference" : "");
FPUTS_SPACES (file, indent + 2, "");
for (unsigned i = 0; i < members.length (); i++)
diff --git a/gcc/ipa-icf.h b/gcc/ipa-icf.h
index adbedd6..db0bc54 100644
--- a/gcc/ipa-icf.h
+++ b/gcc/ipa-icf.h
@@ -29,7 +29,8 @@ class congruence_class
{
public:
/* Congruence class constructor for a new class with _ID. */
- congruence_class (unsigned int _id): in_worklist (false), id(_id)
+ congruence_class (unsigned int _id): in_worklist (false), id(_id),
+ sensitive_reference (false)
{
}
@@ -54,6 +55,9 @@ public:
/* Global unique class identifier. */
unsigned int id;
+
+ /* A function from the class contains a reference to another class. */
+ bool sensitive_reference;
};
/* Semantic item type enum. */
@@ -476,6 +480,10 @@ private:
/* Iterative congruence reduction function. */
void process_cong_reduction (void);
+ /* Identify congruence classes which have an address taken. These
+ classes can be potentially been merged just as thunks. */
+ void identify_address_sensitive_classes (void);
+
/* After reduction is done, we can declare all items in a group
to be equal. PREV_CLASS_COUNT is start number of classes
before reduction. */
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-icf-26.c b/gcc/testsuite/gcc.dg/ipa/ipa-icf-26.c
index 0c5a5a6..f25a251 100644
--- a/gcc/testsuite/gcc.dg/ipa/ipa-icf-26.c
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-icf-26.c
@@ -38,7 +38,7 @@ int main()
return 0;
}
-/* { dg-final { scan-ipa-dump "Semantic equality hit:bar->foo" "icf" } } */
/* { dg-final { scan-ipa-dump "Semantic equality hit:remove->destroy" "icf" } } */
/* { dg-final { scan-ipa-dump "Equal symbols: 2" "icf" } } */
+/* { dg-final { scan-ipa-dump "A function from the congruence class uses a sensitive reference." "icf" } } */
/* { dg-final { cleanup-ipa-dump "icf" } } */
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-icf-33.c b/gcc/testsuite/gcc.dg/ipa/ipa-icf-33.c
index d7e814d..7b6a8ae 100644
--- a/gcc/testsuite/gcc.dg/ipa/ipa-icf-33.c
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-icf-33.c
@@ -23,5 +23,4 @@ int main()
}
/* { dg-final { scan-ipa-dump "Equal symbols: 1" "icf" } } */
-/* { dg-final { scan-ipa-dump "Equal symbols: 1" "icf" } } */
/* { dg-final { cleanup-ipa-dump "icf" } } */
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-icf-34.c b/gcc/testsuite/gcc.dg/ipa/ipa-icf-34.c
new file mode 100644
index 0000000..66bcac5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-icf-34.c
@@ -0,0 +1,44 @@
+/* { dg-do compile } */
+/* { dg-options "-O0 -fipa-icf -fdump-ipa-icf-details" } */
+
+#include <stdlib.h>
+#include <assert.h>
+
+int callback1(int a)
+{
+ return a * a;
+}
+
+int callback2(int a)
+{
+ return a * a;
+}
+
+static int test(int (*callback) (int))
+{
+ if (callback == callback1)
+ return 1;
+
+ return 0;
+}
+
+int foo()
+{
+ return test(&callback1);
+}
+
+int bar()
+{
+ return test(&callback2);
+}
+
+int main()
+{
+ assert (foo() != bar());
+
+ return 0;
+}
+
+/* { dg-final { scan-ipa-dump "Equal symbols: 2" "icf" } } */
+/* { dg-final { scan-ipa-dump "A function from the congruence class uses a sensitive reference." "icf" } } */
+/* { dg-final { cleanup-ipa-dump "icf" } } */
--
2.1.2