public inbox for gcc-cvs@sourceware.org
help / color / mirror / Atom feed
* [gcc r12-4849] addS EAF_NOT_RETURNED_DIRECTLY
@ 2021-11-02 17:44 Jan Hubicka
0 siblings, 0 replies; only message in thread
From: Jan Hubicka @ 2021-11-02 17:44 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:f19791565d7ed31c2a895fc29b772c2c7ed390e8
commit r12-4849-gf19791565d7ed31c2a895fc29b772c2c7ed390e8
Author: Jan Hubicka <hubicka@ucw.cz>
Date: Tue Nov 2 18:43:17 2021 +0100
addS EAF_NOT_RETURNED_DIRECTLY
addS EAF_NOT_RETURNED_DIRECTLY which works similarly as
EAF_NODIRECTESCAPE. Values pointed to by a given argument may be returned but
not the argument itself. This helps PTA quite noticeably because we mostly
care about tracking points to which given memory location can escape.
gcc/ChangeLog:
* tree-core.h (EAF_NOT_RETURNED_DIRECTLY): New flag.
(EAF_NOREAD): Renumber.
* ipa-modref.c (dump_eaf_flags): Dump EAF_NOT_RETURNED_DIRECTLY.
(remove_useless_eaf_flags): Handle EAF_NOT_RETURNED_DIRECTLY
(deref_flags): Likewise.
(modref_lattice::init): Likewise.
(modref_lattice::merge): Likewise.
(merge_call_lhs_flags): Likewise.
(analyze_ssa_name_flags): Likewise.
(modref_merge_call_site_flags): Likewise.
* tree-ssa-structalias.c (handle_call_arg): Likewise.
gcc/testsuite/ChangeLog:
* g++.dg/ipa/modref-1.C: Update template.
* gcc.dg/tree-ssa/modref-10.c: New test.
Diff:
---
gcc/ipa-modref.c | 39 ++++++++++++++++++++++---------
gcc/testsuite/g++.dg/ipa/modref-1.C | 2 +-
gcc/testsuite/gcc.dg/tree-ssa/modref-10.c | 20 ++++++++++++++++
gcc/tree-core.h | 6 ++++-
gcc/tree-ssa-structalias.c | 12 ++++++++--
5 files changed, 64 insertions(+), 15 deletions(-)
diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c
index d866d9ed6b3..c0aae084dbd 100644
--- a/gcc/ipa-modref.c
+++ b/gcc/ipa-modref.c
@@ -160,6 +160,8 @@ dump_eaf_flags (FILE *out, int flags, bool newline = true)
fprintf (out, " unused");
if (flags & EAF_NOT_RETURNED)
fprintf (out, " not_returned");
+ if (flags & EAF_NOT_RETURNED_DIRECTLY)
+ fprintf (out, " not_returned_directly");
if (flags & EAF_NOREAD)
fprintf (out, " noread");
if (newline)
@@ -295,7 +297,7 @@ remove_useless_eaf_flags (int eaf_flags, int ecf_flags, bool returns_void)
else if (ecf_flags & ECF_PURE)
eaf_flags &= ~implicit_pure_eaf_flags;
else if ((ecf_flags & ECF_NORETURN) || returns_void)
- eaf_flags &= ~EAF_NOT_RETURNED;
+ eaf_flags &= ~(EAF_NOT_RETURNED | EAF_NOT_RETURNED_DIRECTLY);
return eaf_flags;
}
@@ -1373,7 +1375,7 @@ memory_access_to (tree op, tree ssa_name)
static int
deref_flags (int flags, bool ignore_stores)
{
- int ret = EAF_NODIRECTESCAPE;
+ int ret = EAF_NODIRECTESCAPE | EAF_NOT_RETURNED_DIRECTLY;
/* If argument is unused just account for
the read involved in dereference. */
if (flags & EAF_UNUSED)
@@ -1458,7 +1460,8 @@ modref_lattice::init ()
{
/* All flags we track. */
int f = EAF_DIRECT | EAF_NOCLOBBER | EAF_NOESCAPE | EAF_UNUSED
- | EAF_NODIRECTESCAPE | EAF_NOT_RETURNED | EAF_NOREAD;
+ | EAF_NODIRECTESCAPE | EAF_NOT_RETURNED |
+ EAF_NOT_RETURNED_DIRECTLY | EAF_NOREAD;
flags = f;
/* Check that eaf_flags_t is wide enough to hold all flags. */
gcc_checking_assert (f == flags);
@@ -1540,6 +1543,8 @@ modref_lattice::merge (int f)
Fnspec machinery does set both so compensate for this. */
if (f & EAF_NOESCAPE)
f |= EAF_NODIRECTESCAPE;
+ if (f & EAF_NOT_RETURNED)
+ f |= EAF_NOT_RETURNED_DIRECTLY;
if ((flags & f) != flags)
{
flags &= f;
@@ -1647,7 +1652,9 @@ merge_call_lhs_flags (gcall *call, int arg, int index, bool deref,
&& (flags & ERF_RETURN_ARG_MASK) != arg)
return;
- if (gimple_call_arg_flags (call, arg) & (EAF_NOT_RETURNED | EAF_UNUSED))
+ int eaf_flags = gimple_call_arg_flags (call, arg);
+
+ if (eaf_flags & (EAF_NOT_RETURNED | EAF_UNUSED))
return;
/* If return value is SSA name determine its flags. */
@@ -1655,12 +1662,14 @@ merge_call_lhs_flags (gcall *call, int arg, int index, bool deref,
{
tree lhs = gimple_call_lhs (call);
analyze_ssa_name_flags (lhs, lattice, depth + 1, ipa);
- if (deref)
+ if (deref || (eaf_flags & EAF_NOT_RETURNED_DIRECTLY))
lattice[index].merge_deref (lattice[SSA_NAME_VERSION (lhs)], false);
else
lattice[index].merge (lattice[SSA_NAME_VERSION (lhs)]);
}
/* In the case of memory store we can do nothing. */
+ else if (eaf_flags & EAF_NOT_RETURNED_DIRECTLY)
+ lattice[index].merge (deref_flags (0, false));
else
lattice[index].merge (0);
}
@@ -1731,11 +1740,13 @@ analyze_ssa_name_flags (tree name, vec<modref_lattice> &lattice, int depth,
&& DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
;
else if (gimple_return_retval (ret) == name)
- lattice[index].merge (~(EAF_UNUSED | EAF_NOT_RETURNED));
+ lattice[index].merge (~(EAF_UNUSED | EAF_NOT_RETURNED
+ | EAF_NOT_RETURNED_DIRECTLY));
else if (memory_access_to (gimple_return_retval (ret), name))
{
lattice[index].merge_direct_load ();
- lattice[index].merge (~(EAF_UNUSED | EAF_NOT_RETURNED));
+ lattice[index].merge (~(EAF_UNUSED | EAF_NOT_RETURNED
+ | EAF_NOT_RETURNED_DIRECTLY));
}
}
/* Account for LHS store, arg loads and flags from callee function. */
@@ -1794,7 +1805,8 @@ analyze_ssa_name_flags (tree name, vec<modref_lattice> &lattice, int depth,
if (!(ecf_flags & (ECF_CONST | ECF_NOVOPS)))
{
int call_flags = gimple_call_arg_flags (call, i)
- | EAF_NOT_RETURNED;
+ | EAF_NOT_RETURNED
+ | EAF_NOT_RETURNED_DIRECTLY;
if (ignore_stores)
call_flags |= ignore_stores_eaf_flags;
@@ -1817,7 +1829,8 @@ analyze_ssa_name_flags (tree name, vec<modref_lattice> &lattice, int depth,
{
int call_flags = deref_flags
(gimple_call_arg_flags (call, i)
- | EAF_NOT_RETURNED, ignore_stores);
+ | EAF_NOT_RETURNED
+ | EAF_NOT_RETURNED_DIRECTLY, ignore_stores);
if (!record_ipa)
lattice[index].merge (call_flags);
else
@@ -3858,14 +3871,18 @@ modref_merge_call_site_flags (escape_summary *sum,
flags_lto |= ignore_stores_eaf_flags;
}
/* Returning the value is already accounted to at local propagation. */
- flags |= ee->min_flags | EAF_NOT_RETURNED;
- flags_lto |= ee->min_flags | EAF_NOT_RETURNED;
+ flags |= ee->min_flags | EAF_NOT_RETURNED | EAF_NOT_RETURNED_DIRECTLY;
+ flags_lto |= ee->min_flags | EAF_NOT_RETURNED | EAF_NOT_RETURNED_DIRECTLY;
/* Noescape implies that value also does not escape directly.
Fnspec machinery does set both so compensate for this. */
if (flags & EAF_NOESCAPE)
flags |= EAF_NODIRECTESCAPE;
if (flags_lto & EAF_NOESCAPE)
flags_lto |= EAF_NODIRECTESCAPE;
+ if (flags & EAF_NOT_RETURNED)
+ flags |= EAF_NOT_RETURNED_DIRECTLY;
+ if (flags_lto & EAF_NOT_RETURNED)
+ flags_lto |= EAF_NOT_RETURNED_DIRECTLY;
if (!(flags & EAF_UNUSED)
&& cur_summary && ee->parm_index < (int)cur_summary->arg_flags.length ())
{
diff --git a/gcc/testsuite/g++.dg/ipa/modref-1.C b/gcc/testsuite/g++.dg/ipa/modref-1.C
index 0acae2114dd..eaa14ea5c7f 100644
--- a/gcc/testsuite/g++.dg/ipa/modref-1.C
+++ b/gcc/testsuite/g++.dg/ipa/modref-1.C
@@ -31,5 +31,5 @@ int main()
return 0;
}
/* { dg-final { scan-tree-dump "Function found to be const: {anonymous}::B::genB" "local-pure-const1" } } */
-/* { dg-final { scan-tree-dump "Retslot flags: direct noescape nodirectescape not_returned noread" "modref1" } } */
+/* { dg-final { scan-tree-dump "Retslot flags: direct noescape nodirectescape not_returned not_returned_directly noread" "modref1" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/modref-10.c b/gcc/testsuite/gcc.dg/tree-ssa/modref-10.c
new file mode 100644
index 00000000000..c608408809d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/modref-10.c
@@ -0,0 +1,20 @@
+/* { dg-do link } */
+/* { dg-options "-O2 -fdump-tree-modref1" } */
+void linker_error ();
+__attribute__((noinline))
+int *
+test (int **a)
+{
+ return *a;
+}
+int
+main()
+{
+ int val;
+ int *a=&val;
+ int *b = test (&a);
+ if (b == (int *)&a)
+ linker_error ();
+ return 0;
+}
+/* { dg-final { scan-tree-dump "parm 0 flags: noclobber noescape nodirectescape not_returned_directly" "modref1"} } */
diff --git a/gcc/tree-core.h b/gcc/tree-core.h
index d3d2a8d812f..f0c65a25f07 100644
--- a/gcc/tree-core.h
+++ b/gcc/tree-core.h
@@ -117,8 +117,12 @@ struct die_struct;
/* Nonzero if the argument does not escape to return value. */
#define EAF_NOT_RETURNED (1 << 5)
+/* Nonzero if the argument itself does not escape
+ to return value but memory referenced by it may escape. */
+#define EAF_NOT_RETURNED_DIRECTLY (1 << 6)
+
/* Nonzero if the argument is not read. */
-#define EAF_NOREAD (1 << 6)
+#define EAF_NOREAD (1 << 7)
/* Call return flags. */
/* Mask for the argument number that is returned. Lower two bits of
diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c
index 99072df0768..5f24c0171f0 100644
--- a/gcc/tree-ssa-structalias.c
+++ b/gcc/tree-ssa-structalias.c
@@ -4082,8 +4082,16 @@ handle_call_arg (gcall *stmt, tree arg, vec<ce_s> *results, int flags,
{
struct constraint_expr cexpr;
cexpr.var = tem->id;
- cexpr.type = SCALAR;
- cexpr.offset = 0;
+ if (flags & EAF_NOT_RETURNED_DIRECTLY)
+ {
+ cexpr.type = DEREF;
+ cexpr.offset = UNKNOWN_OFFSET;
+ }
+ else
+ {
+ cexpr.type = SCALAR;
+ cexpr.offset = 0;
+ }
results->safe_push (cexpr);
}
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2021-11-02 17:44 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-11-02 17:44 [gcc r12-4849] addS EAF_NOT_RETURNED_DIRECTLY Jan Hubicka
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).