The following records whether a points-to solution contains any
local automatic variables, not including parameters or result storage.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
This was requested by HJ (or rather suggested by me).
Richard.
* tree-ssa-alias.h (pt_solution::vars_contains_auto): New.
(ptr_deref_may_alias_auto_p): Declare.
(pt_solution_includes_auto): Likewise.
* tree-ssa-structalias.cc (set_uids_in_ptset): Record auto
variables.
(pt_solution_includes_auto): New function.
(ipa_escaped_pt): Adjust.
* tree-ssa-alias.cc (ptr_deref_may_alias_auto_p): New function.
---
gcc/tree-ssa-alias.cc | 24 ++++++++++++++++++++++++
gcc/tree-ssa-alias.h | 4 ++++
gcc/tree-ssa-structalias.cc | 30 +++++++++++++++++++++++++++++-
3 files changed, 57 insertions(+), 1 deletion(-)
diff --git a/gcc/tree-ssa-alias.cc b/gcc/tree-ssa-alias.cc
index 467ef1c215f..1d10f6dbd97 100644
--- a/gcc/tree-ssa-alias.cc
+++ b/gcc/tree-ssa-alias.cc
@@ -238,6 +238,30 @@ ptr_deref_may_alias_global_p (tree ptr, bool
escaped_local_p)
return pt_solution_includes_global (&pi->pt, escaped_local_p);
}
+/* Return true, if dereferencing PTR may alias with a local automatic
+ variable. */
+
+bool
+ptr_deref_may_alias_auto_p (tree ptr)
+{
+ struct ptr_info_def *pi;
+
+ /* If we end up with a pointer constant here that may point
+ to local stack memory. */
+ if (TREE_CODE (ptr) != SSA_NAME)
+ return true;
+
+ pi = SSA_NAME_PTR_INFO (ptr);
+
+ /* If we do not have points-to information for this variable,
+ we have to punt. */
+ if (!pi)
+ return true;
+
+ return pt_solution_includes_auto (&pi->pt);
+}
+
+
/* Return true if dereferencing PTR may alias DECL.
The caller is responsible for applying TBAA to see if PTR
may access DECL at all. */
diff --git a/gcc/tree-ssa-alias.h b/gcc/tree-ssa-alias.h
index e0785c5d4bb..ccac9c539bb 100644
--- a/gcc/tree-ssa-alias.h
+++ b/gcc/tree-ssa-alias.h
@@ -54,6 +54,8 @@ struct GTY(()) pt_solution
/* Nonzero if the vars bitmap includes a variable included in 'nonlocal'. */
unsigned int vars_contains_nonlocal : 1;
+ /* Nonzero if the vars bitmap includes a local automatic variable. */
+ unsigned int vars_contains_auto : 1;
/* Nonzero if the vars bitmap includes a variable included in 'escaped'. */
unsigned int vars_contains_escaped : 1;
/* Nonzero if the vars bitmap includes a anonymous heap variable that
@@ -127,6 +129,7 @@ extern tree ao_ref_base_alias_ptr_type (ao_ref *);
extern bool ao_ref_alignment (ao_ref *, unsigned int *,
unsigned HOST_WIDE_INT *);
extern bool ptr_deref_may_alias_global_p (tree, bool);
+extern bool ptr_deref_may_alias_auto_p (tree);
extern bool ptr_derefs_may_alias_p (tree, tree);
extern bool ptrs_compare_unequal (tree, tree);
extern bool ref_may_alias_global_p (tree, bool);
@@ -182,6 +185,7 @@ extern unsigned int compute_may_aliases (void);
extern bool pt_solution_empty_p (const pt_solution *);
extern bool pt_solution_singleton_or_null_p (struct pt_solution *, unsigned *);
extern bool pt_solution_includes_global (struct pt_solution *, bool);
+extern bool pt_solution_includes_auto (struct pt_solution *);
extern bool pt_solution_includes (struct pt_solution *, const_tree);
extern bool pt_solution_includes_const_pool (struct pt_solution *);
extern bool pt_solutions_intersect (struct pt_solution *, struct pt_solution
*);
diff --git a/gcc/tree-ssa-structalias.cc b/gcc/tree-ssa-structalias.cc
index ab6658a0981..3b557cc4cd1 100644
--- a/gcc/tree-ssa-structalias.cc
+++ b/gcc/tree-ssa-structalias.cc
@@ -801,6 +801,13 @@ set_uids_in_ptset (bitmap into, bitmap from, struct
pt_solution *pt,
&& ! auto_var_in_fn_p (vi->decl, fndecl)))
pt->vars_contains_nonlocal = true;
+ /* If the variable is an automatic in the local stack frame, record
+ that. Note this does not include PARM_DECL and RESULT_DECL which
+ are managed by the caller. */
+ if (VAR_P (vi->decl)
+ && auto_var_in_fn_p (vi->decl, fndecl))
+ pt->vars_contains_auto = true;
+
/* If we have a variable that is interposable record that fact
for pointer comparison simplification. */
if (VAR_P (vi->decl)
@@ -1120,6 +1127,27 @@ pt_solution_includes_global (struct pt_solution *pt,
bool escaped_local_p)
return false;
}
+/* Return true if the points-to solution *PT includes local automatic
+ storage. */
+
+bool
+pt_solution_includes_auto (struct pt_solution *pt)
+{
+ if (pt->anything
+ || pt->vars_contains_auto)
+ return true;
+
+ /* 'escaped' is also a placeholder so we have to look into it. */
+ if (pt->escaped)
+ return pt_solution_includes_auto (&cfun->gimple_df->escaped);
+
+ if (pt->ipa_escaped)
+ return pt_solution_includes_auto (&ipa_escaped_pt);
+
+ return false;
+}
+
+
/* Return true if the points-to solution *PT includes the variable
declaration DECL. */
@@ -1803,7 +1831,7 @@ make_pass_build_ealias (gcc::context *ctxt)
/* IPA PTA solutions for ESCAPED. */
struct pt_solution ipa_escaped_pt
= { true, false, false, false, false, false,
- false, false, false, false, false, NULL };
+ false, false, false, false, false, false, NULL };
/* Execute the driver for IPA PTA. */
--
2.51.0
