Hi!
The following testcase is miscompiled, because VN during cunrolli changes
__bos argument from address of a larger field to address of a smaller field
and so __builtin_object_size (, 1) then folds into smaller value than the
actually available size.
copy_reference_ops_from_ref has a hack for this, but it was using
cfun->after_inlining as a check whether the hack can be ignored, and
cunrolli is after_inlining.
This patch uses a property to make it exact (set at the end of objsz
pass that doesn't do insert_min_max_p) and additionally based on discussions
in the PR moves the objsz pass earlier after IPA.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2021-07-13 Jakub Jelinek <ja...@redhat.com>
Richard Biener <rguent...@suse.de>
PR tree-optimization/101419
* tree-pass.h (PROP_objsz): Define.
(make_pass_early_object_sizes): Declare.
* passes.def (pass_all_early_optimizations): Rename pass_object_sizes
there to pass_early_object_sizes, drop parameter.
(pass_all_optimizations): Move pass_object_sizes right after pass_ccp,
drop parameter, move pass_post_ipa_warn right after that.
* tree-object-size.c (pass_object_sizes::execute): Rename to...
(object_sizes_execute): ... this. Add insert_min_max_p argument.
(pass_data_object_sizes): Move after object_sizes_execute.
(pass_object_sizes): Likewise. In execute method call
object_sizes_execute, drop set_pass_param method and insert_min_max_p
non-static data member and its initializer in the ctor.
(pass_data_early_object_sizes, pass_early_object_sizes,
make_pass_early_object_sizes): New.
* tree-ssa-sccvn.c (copy_reference_ops_from_ref): Use
(cfun->curr_properties & PROP_objsz) instead of cfun->after_inlining.
* gcc.dg/builtin-object-size-10.c: Pass -fdump-tree-early_objsz-details
instead of -fdump-tree-objsz1-details in dg-options and adjust names
of dump file in scan-tree-dump.
* gcc.dg/pr101419.c: New test.
--- gcc/tree-pass.h.jj 2021-01-27 10:10:00.525903635 +0100
+++ gcc/tree-pass.h 2021-07-12 17:23:42.322648068 +0200
@@ -208,6 +208,7 @@ protected:
#define PROP_gimple_lcf (1 << 1) /* lowered control flow
*/
#define PROP_gimple_leh (1 << 2) /* lowered eh */
#define PROP_cfg (1 << 3)
+#define PROP_objsz (1 << 4) /* object sizes computed */
#define PROP_ssa (1 << 5)
#define PROP_no_crit_edges (1 << 6)
#define PROP_rtl (1 << 7)
@@ -426,6 +427,7 @@ extern gimple_opt_pass *make_pass_omp_ta
extern gimple_opt_pass *make_pass_oacc_device_lower (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_omp_device_lower (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_object_sizes (gcc::context *ctxt);
+extern gimple_opt_pass *make_pass_early_object_sizes (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_warn_printf (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_strlen (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_fold_builtins (gcc::context *ctxt);
--- gcc/passes.def.jj 2021-05-19 09:16:34.434046683 +0200
+++ gcc/passes.def 2021-07-12 17:41:38.274859148 +0200
@@ -74,7 +74,7 @@ along with GCC; see the file COPYING3.
NEXT_PASS (pass_all_early_optimizations);
PUSH_INSERT_PASSES_WITHIN (pass_all_early_optimizations)
NEXT_PASS (pass_remove_cgraph_callee_edges);
- NEXT_PASS (pass_object_sizes, true /* insert_min_max_p */);
+ NEXT_PASS (pass_early_object_sizes);
/* Don't record nonzero bits before IPA to avoid
using too much memory. */
NEXT_PASS (pass_ccp, false /* nonzero_p */);
@@ -194,14 +194,14 @@ along with GCC; see the file COPYING3.
They ensure memory accesses are not indirect wherever possible. */
NEXT_PASS (pass_strip_predict_hints, false /* early_p */);
NEXT_PASS (pass_ccp, true /* nonzero_p */);
- NEXT_PASS (pass_post_ipa_warn);
/* After CCP we rewrite no longer addressed locals into SSA
form if possible. */
+ NEXT_PASS (pass_object_sizes);
+ NEXT_PASS (pass_post_ipa_warn);
NEXT_PASS (pass_complete_unrolli);
NEXT_PASS (pass_backprop);
NEXT_PASS (pass_phiprop);
NEXT_PASS (pass_forwprop);
- NEXT_PASS (pass_object_sizes, false /* insert_min_max_p */);
/* pass_build_alias is a dummy pass that ensures that we
execute TODO_rebuild_alias at this point. */
NEXT_PASS (pass_build_alias);
--- gcc/tree-object-size.c.jj 2021-01-04 10:25:39.911221618 +0100
+++ gcc/tree-object-size.c 2021-07-12 17:47:30.497018569 +0200
@@ -1304,45 +1304,6 @@ fini_object_sizes (void)
}
}
-
-/* Simple pass to optimize all __builtin_object_size () builtins. */
-
-namespace {
-
-const pass_data pass_data_object_sizes =
-{
- GIMPLE_PASS, /* type */
- "objsz", /* name */
- OPTGROUP_NONE, /* optinfo_flags */
- TV_NONE, /* tv_id */
- ( PROP_cfg | PROP_ssa ), /* properties_required */
- 0, /* properties_provided */
- 0, /* properties_destroyed */
- 0, /* todo_flags_start */
- 0, /* todo_flags_finish */
-};
-
-class pass_object_sizes : public gimple_opt_pass
-{
-public:
- pass_object_sizes (gcc::context *ctxt)
- : gimple_opt_pass (pass_data_object_sizes, ctxt), insert_min_max_p (false)
- {}
-
- /* opt_pass methods: */
- opt_pass * clone () { return new pass_object_sizes (m_ctxt); }
- void set_pass_param (unsigned int n, bool param)
- {
- gcc_assert (n == 0);
- insert_min_max_p = param;
- }
- virtual unsigned int execute (function *);
-
- private:
- /* Determines whether the pass instance creates MIN/MAX_EXPRs. */
- bool insert_min_max_p;
-}; // class pass_object_sizes
-
/* Dummy valueize function. */
static tree
@@ -1351,8 +1312,8 @@ do_valueize (tree t)
return t;
}
-unsigned int
-pass_object_sizes::execute (function *fun)
+static unsigned int
+object_sizes_execute (function *fun, bool insert_min_max_p)
{
basic_block bb;
FOR_EACH_BB_FN (bb, fun)
@@ -1453,6 +1414,38 @@ pass_object_sizes::execute (function *fu
return 0;
}
+/* Simple pass to optimize all __builtin_object_size () builtins. */
+
+namespace {
+
+const pass_data pass_data_object_sizes =
+{
+ GIMPLE_PASS, /* type */
+ "objsz", /* name */
+ OPTGROUP_NONE, /* optinfo_flags */
+ TV_NONE, /* tv_id */
+ ( PROP_cfg | PROP_ssa ), /* properties_required */
+ PROP_objsz, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ 0, /* todo_flags_finish */
+};
+
+class pass_object_sizes : public gimple_opt_pass
+{
+public:
+ pass_object_sizes (gcc::context *ctxt)
+ : gimple_opt_pass (pass_data_object_sizes, ctxt)
+ {}
+
+ /* opt_pass methods: */
+ opt_pass * clone () { return new pass_object_sizes (m_ctxt); }
+ virtual unsigned int execute (function *fun)
+ {
+ return object_sizes_execute (fun, false);
+ }
+}; // class pass_object_sizes
+
} // anon namespace
gimple_opt_pass *
@@ -1460,3 +1453,42 @@ make_pass_object_sizes (gcc::context *ct
{
return new pass_object_sizes (ctxt);
}
+
+/* Early version of pass to optimize all __builtin_object_size () builtins. */
+
+namespace {
+
+const pass_data pass_data_early_object_sizes =
+{
+ GIMPLE_PASS, /* type */
+ "early_objsz", /* name */
+ OPTGROUP_NONE, /* optinfo_flags */
+ TV_NONE, /* tv_id */
+ ( PROP_cfg | PROP_ssa ), /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ 0, /* todo_flags_finish */
+};
+
+class pass_early_object_sizes : public gimple_opt_pass
+{
+public:
+ pass_early_object_sizes (gcc::context *ctxt)
+ : gimple_opt_pass (pass_data_early_object_sizes, ctxt)
+ {}
+
+ /* opt_pass methods: */
+ virtual unsigned int execute (function *fun)
+ {
+ return object_sizes_execute (fun, true);
+ }
+}; // class pass_object_sizes
+
+} // anon namespace
+
+gimple_opt_pass *
+make_pass_early_object_sizes (gcc::context *ctxt)
+{
+ return new pass_early_object_sizes (ctxt);
+}
--- gcc/tree-ssa-sccvn.c.jj 2021-06-09 10:20:08.988342285 +0200
+++ gcc/tree-ssa-sccvn.c 2021-07-12 13:14:33.482962387 +0200
@@ -925,12 +925,10 @@ copy_reference_ops_from_ref (tree ref, v
+ (wi::to_offset (bit_offset) >> LOG2_BITS_PER_UNIT));
/* Probibit value-numbering zero offset components
of addresses the same before the pass folding
- __builtin_object_size had a chance to run
- (checking cfun->after_inlining does the
- trick here). */
+ __builtin_object_size had a chance to run. */
if (TREE_CODE (orig) != ADDR_EXPR
|| maybe_ne (off, 0)
- || cfun->after_inlining)
+ || (cfun->curr_properties & PROP_objsz))
off.to_shwi (&temp.off);
}
}
--- gcc/testsuite/gcc.dg/builtin-object-size-10.c.jj 2020-01-12
11:54:37.387398714 +0100
+++ gcc/testsuite/gcc.dg/builtin-object-size-10.c 2021-07-12
17:44:00.795900485 +0200
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-objsz1-details" } */
+/* { dg-options "-O2 -fdump-tree-early_objsz-details" } */
// { dg-skip-if "packed attribute missing for drone_source_packet" {
"epiphany-*-*" } }
typedef struct {
@@ -22,5 +22,5 @@ foo(char *x)
return dpkt;
}
-/* { dg-final { scan-tree-dump "maximum object size 21" "objsz1" } } */
-/* { dg-final { scan-tree-dump "maximum subobject size 16" "objsz1" } } */
+/* { dg-final { scan-tree-dump "maximum object size 21" "early_objsz" } } */
+/* { dg-final { scan-tree-dump "maximum subobject size 16" "early_objsz" } } */
--- gcc/testsuite/gcc.dg/pr101419.c.jj 2021-07-12 13:33:47.492945100 +0200
+++ gcc/testsuite/gcc.dg/pr101419.c 2021-07-12 13:33:33.756135703 +0200
@@ -0,0 +1,62 @@
+/* PR tree-optimization/101419 */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+typedef __SIZE_TYPE__ size_t;
+void baz (int, int) __attribute__((__warning__("detected overflow")));
+
+union U {
+ int i;
+ char c;
+};
+
+static void
+foo (union U *u)
+{
+ if (__builtin_object_size (&u->c, 1) < sizeof (u->c))
+ baz (__builtin_object_size (&u->c, 1), sizeof (u->c)); /* { dg-bogus
"detected overflow" } */
+ __builtin_memset (&u->c, 0, sizeof (u->c));
+
+ if (__builtin_object_size (&u->i, 1) < sizeof (u->i))
+ baz (__builtin_object_size (&u->i, 1), sizeof (u->i)); /* { dg-bogus
"detected overflow" } */
+ __builtin_memset (&u->i, 0, sizeof (u->i));
+}
+
+void
+bar (union U *u)
+{
+ int i, j;
+ for (i = 0; i < 1; i++)
+ {
+ foo (u);
+ for (j = 0; j < 2; j++)
+ asm volatile ("");
+ }
+}
+
+static void
+qux (void *p, size_t q)
+{
+ if (__builtin_object_size (p, 1) < q)
+ baz (__builtin_object_size (p, 1), q); /* { dg-bogus
"detected overflow" } */
+ __builtin_memset (p, 0, q);
+}
+
+static void
+corge (union U *u)
+{
+ qux (&u->c, sizeof (u->c));
+ qux (&u->i, sizeof (u->i));
+}
+
+void
+garply (union U *u)
+{
+ int i, j;
+ for (i = 0; i < 1; i++)
+ {
+ corge (u);
+ for (j = 0; j < 2; j++)
+ asm volatile ("");
+ }
+}
Jakub
