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re PR ipa/68331 ([meta-bug] fipa-pta issues)

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2015-12-10  Richard Biener  <rguenther@suse.de>

	PR ipa/68331
	* tree-ssa-structalias.c (set_uids_in_ptset): Add fndecl
	parameter and make vars_contains_nonlocal properly have
	function-scope semantics in IPA mode.
	(find_what_var_points_to): Add fndecl parameter.
	(find_what_p_points_to): Likewise.
	(pt_solution_includes_global): Remove IPA PTA early out.
	(compute_points_to_sets): Adjust.
	(ipa_pta_execute): Likewise.  Clear final_solutions after
	each function.

	* gcc.dg/torture/ipa-pta-3.c: New testcase.
	* g++.dg/ipa/ipa-pta-1.C: Likewise.

From-SVN: r231498
This commit is contained in:
Richard Biener 2015-12-10 09:41:08 +00:00 • committed by Richard Biener
parent e53ed9f4c5
commit ee7d29b43f
5 changed files with 115 additions and 27 deletions
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13
gcc/ChangeLog
View file

@ -1,3 +1,16 @@
2015-12-10 Richard Biener <rguenther@suse.de>
PR ipa/68331
* tree-ssa-structalias.c (set_uids_in_ptset): Add fndecl
parameter and make vars_contains_nonlocal properly have
function-scope semantics in IPA mode.
(find_what_var_points_to): Add fndecl parameter.
(find_what_p_points_to): Likewise.
(pt_solution_includes_global): Remove IPA PTA early out.
(compute_points_to_sets): Adjust.
(ipa_pta_execute): Likewise. Clear final_solutions after
each function.
2015-12-10 Tom de Vries <tom@codesourcery.com>
PR ada/65102

6
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,9 @@
2015-12-10 Richard Biener <rguenther@suse.de>
PR ipa/68331
* gcc.dg/torture/ipa-pta-3.c: New testcase.
* g++.dg/ipa/ipa-pta-1.C: Likewise.
2015-12-10 Richard Biener <rguenther@suse.de>
PR ipa/68721

35
gcc/testsuite/g++.dg/ipa/ipa-pta-1.C Normal file
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@ -0,0 +1,35 @@
/* { dg-do run } */
/* { dg-options "-O2 -fipa-pta" } */
struct A {
A() {ptr=&b;}
A(const A &a) {ptr = &b;}
void test() { if (ptr != &b) __builtin_abort ();}
int b;
int *ptr;
};
A test1(A a)
{
a.test();
return a;
}
A test2(A a)
{
a.test();
return a;
}
__attribute__ ((noinline))
static void
test_me (A (*t)(A))
{
struct A a, b=t(a);
b.test ();
}
int
main()
{
test_me (test1);
test_me (test2);
return 0;
}

19
gcc/testsuite/gcc.dg/torture/ipa-pta-3.c Normal file
View file

@ -0,0 +1,19 @@
/* { dg-do run } */
/* { dg-additional-options "-fipa-pta" } */
extern void abort (void);
extern void *malloc (__SIZE_TYPE__);
static int *p;
static void __attribute__((noinline,noclone)) foo ()
{
p = (int *) malloc (24);
*p = 2;
}
int main()
{
foo ();
if (*p != 2)
abort ();
return 0;
}

69
gcc/tree-ssa-structalias.c
View file

@ -159,9 +159,7 @@
The is_global_var bit which marks escape points is overly conservative
in IPA mode. Split it to is_escape_point and is_global_var - only
externally visible globals are escape points in IPA mode. This is
also needed to fix the pt_solution_includes_global predicate
(and thus ptr_deref_may_alias_global_p).
externally visible globals are escape points in IPA mode.
The way we introduce DECL_PT_UID to avoid fixing up all points-to
sets in the translation unit when we copy a DECL during inlining
@ -186,6 +184,7 @@
propagating it simply like the clobber / uses solutions. The
solution can go alongside the non-IPA espaced solution and be
used to query which vars escape the unit through a function.
This is also required to make the escaped-HEAP trick work in IPA mode.
We never put function decls in points-to sets so we do not
keep the set of called functions for indirect calls.
@ -6150,7 +6149,8 @@ shared_bitmap_add (bitmap pt_vars)
/* Set bits in INTO corresponding to the variable uids in solution set FROM. */
static void
set_uids_in_ptset (bitmap into, bitmap from, struct pt_solution *pt)
set_uids_in_ptset (bitmap into, bitmap from, struct pt_solution *pt,
tree fndecl)
{
unsigned int i;
bitmap_iterator bi;
@ -6188,7 +6188,19 @@ set_uids_in_ptset (bitmap into, bitmap from, struct pt_solution *pt)
/* Add the decl to the points-to set. Note that the points-to
set contains global variables. */
bitmap_set_bit (into, DECL_PT_UID (vi->decl));
if (vi->is_global_var)
if (vi->is_global_var
/* In IPA mode the escaped_heap trick doesn't work as
ESCAPED is escaped from the unit but
pt_solution_includes_global needs to answer true for
all variables not automatic within a function.
For the same reason is_global_var is not the
correct flag to track - local variables from other
functions also need to be considered global.
Conveniently all HEAP vars are not put in function
scope. */
|| (in_ipa_mode
&& fndecl
&& ! auto_var_in_fn_p (vi->decl, fndecl)))
pt->vars_contains_nonlocal = true;
}
}
@ -6198,7 +6210,7 @@ set_uids_in_ptset (bitmap into, bitmap from, struct pt_solution *pt)
/* Compute the points-to solution *PT for the variable VI. */
static struct pt_solution
find_what_var_points_to (varinfo_t orig_vi)
find_what_var_points_to (tree fndecl, varinfo_t orig_vi)
{
unsigned int i;
bitmap_iterator bi;
@ -6263,7 +6275,7 @@ find_what_var_points_to (varinfo_t orig_vi)
finished_solution = BITMAP_GGC_ALLOC ();
stats.points_to_sets_created++;
set_uids_in_ptset (finished_solution, vi->solution, pt);
set_uids_in_ptset (finished_solution, vi->solution, pt, fndecl);
result = shared_bitmap_lookup (finished_solution);
if (!result)
{
@ -6282,7 +6294,7 @@ find_what_var_points_to (varinfo_t orig_vi)
/* Given a pointer variable P, fill in its points-to set. */
static void
find_what_p_points_to (tree p)
find_what_p_points_to (tree fndecl, tree p)
{
struct ptr_info_def *pi;
tree lookup_p = p;
@ -6301,7 +6313,7 @@ find_what_p_points_to (tree p)
return;
pi = get_ptr_info (p);
pi->pt = find_what_var_points_to (vi);
pi->pt = find_what_var_points_to (fndecl, vi);
}
@ -6467,12 +6479,6 @@ pt_solution_includes_global (struct pt_solution *pt)
if (pt->ipa_escaped)
return pt_solution_includes_global (&ipa_escaped_pt);
/* ??? This predicate is not correct for the IPA-PTA solution
as we do not properly distinguish between unit escape points
and global variables. */
if (cfun->gimple_df->ipa_pta)
return true;
return false;
}
@ -6969,7 +6975,8 @@ compute_points_to_sets (void)
solve_constraints ();
/* Compute the points-to set for ESCAPED used for call-clobber analysis. */
cfun->gimple_df->escaped = find_what_var_points_to (get_varinfo (escaped_id));
cfun->gimple_df->escaped = find_what_var_points_to (cfun->decl,
get_varinfo (escaped_id));
/* Make sure the ESCAPED solution (which is used as placeholder in
other solutions) does not reference itself. This simplifies
@ -6982,7 +6989,7 @@ compute_points_to_sets (void)
tree ptr = ssa_name (i);
if (ptr
&& POINTER_TYPE_P (TREE_TYPE (ptr)))
find_what_p_points_to (ptr);
find_what_p_points_to (cfun->decl, ptr);
}
/* Compute the call-used/clobbered sets. */
@ -7004,7 +7011,7 @@ compute_points_to_sets (void)
memset (pt, 0, sizeof (struct pt_solution));
else if ((vi = lookup_call_use_vi (stmt)) != NULL)
{
*pt = find_what_var_points_to (vi);
*pt = find_what_var_points_to (cfun->decl, vi);
/* Escaped (and thus nonlocal) variables are always
implicitly used by calls. */
/* ??? ESCAPED can be empty even though NONLOCAL
@ -7025,7 +7032,7 @@ compute_points_to_sets (void)
memset (pt, 0, sizeof (struct pt_solution));
else if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
{
*pt = find_what_var_points_to (vi);
*pt = find_what_var_points_to (cfun->decl, vi);
/* Escaped (and thus nonlocal) variables are always
implicitly clobbered by calls. */
/* ??? ESCAPED can be empty even though NONLOCAL
@ -7565,7 +7572,7 @@ ipa_pta_execute (void)
??? Note that the computed escape set is not correct
for the whole unit as we fail to consider graph edges to
externally visible functions. */
ipa_escaped_pt = find_what_var_points_to (get_varinfo (escaped_id));
ipa_escaped_pt = find_what_var_points_to (NULL, get_varinfo (escaped_id));
/* Make sure the ESCAPED solution (which is used as placeholder in
other solutions) does not reference itself. This simplifies
@ -7591,7 +7598,7 @@ ipa_pta_execute (void)
{
if (ptr
&& POINTER_TYPE_P (TREE_TYPE (ptr)))
find_what_p_points_to (ptr);
find_what_p_points_to (node->decl, ptr);
}
/* Compute the call-use and call-clobber sets for indirect calls
@ -7625,10 +7632,10 @@ ipa_pta_execute (void)
{
*gimple_call_clobber_set (stmt)
= find_what_var_points_to
(first_vi_for_offset (fi, fi_clobbers));
(node->decl, first_vi_for_offset (fi, fi_clobbers));
*gimple_call_use_set (stmt)
= find_what_var_points_to
(first_vi_for_offset (fi, fi_uses));
(node->decl, first_vi_for_offset (fi, fi_uses));
}
/* Handle direct calls to external functions. */
else if (decl)
@ -7638,7 +7645,7 @@ ipa_pta_execute (void)
memset (pt, 0, sizeof (struct pt_solution));
else if ((vi = lookup_call_use_vi (stmt)) != NULL)
{
*pt = find_what_var_points_to (vi);
*pt = find_what_var_points_to (node->decl, vi);
/* Escaped (and thus nonlocal) variables are always
implicitly used by calls. */
/* ??? ESCAPED can be empty even though NONLOCAL
@ -7659,7 +7666,7 @@ ipa_pta_execute (void)
memset (pt, 0, sizeof (struct pt_solution));
else if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
{
*pt = find_what_var_points_to (vi);
*pt = find_what_var_points_to (node->decl, vi);
/* Escaped (and thus nonlocal) variables are always
implicitly clobbered by calls. */
/* ??? ESCAPED can be empty even though NONLOCAL
@ -7719,13 +7726,15 @@ ipa_pta_execute (void)
if (!uses->anything)
{
sol = find_what_var_points_to
(first_vi_for_offset (vi, fi_uses));
(node->decl,
first_vi_for_offset (vi, fi_uses));
pt_solution_ior_into (uses, &sol);
}
if (!clobbers->anything)
{
sol = find_what_var_points_to
(first_vi_for_offset (vi, fi_clobbers));
(node->decl,
first_vi_for_offset (vi, fi_clobbers));
pt_solution_ior_into (clobbers, &sol);
}
}
@ -7735,6 +7744,12 @@ ipa_pta_execute (void)
}
fn->gimple_df->ipa_pta = true;
/* We have to re-set the final-solution cache after each function
because what is a "global" is dependent on function context. */
final_solutions->empty ();
obstack_free (&final_solutions_obstack, NULL);
gcc_obstack_init (&final_solutions_obstack);
}
delete_points_to_sets ();