[gcc r11-3734] Disable TBAA in some uses of call_may_clobber_ref_p

[gcc r11-3734] Disable TBAA in some uses of call_may_clobber_ref_p

[Jan Hubicka]

https://gcc.gnu.org/g:3e1123e52f8eca2650efa0bc81768792d328961f

commit r11-3734-g3e1123e52f8eca2650efa0bc81768792d328961f
Author: Jan Hubicka <jh@suse.cz>
Date:   Thu Oct 8 17:15:58 2020 +0200

    Disable TBAA in some uses of call_may_clobber_ref_p
    
            * tree-nrv.c (dest_safe_for_nrv_p): Disable tbaa in
            call_may_clobber_ref_p and ref_maybe_used_by_stmt_p.
            * tree-tailcall.c (find_tail_calls): Likewise.
            * tree-ssa-alias.c (call_may_clobber_ref_p): Add tbaa_p parameter.
            * tree-ssa-alias.h (call_may_clobber_ref_p): Update prototype.
            * tree-ssa-sccvn.c (vn_reference_lookup_3): Pass data->tbaa_p
            to call_may_clobber_ref_p_1.

Diff:
---
 gcc/tree-nrv.c       | 4 ++--
 gcc/tree-ssa-alias.c | 4 ++--
 gcc/tree-ssa-alias.h | 2 +-
 gcc/tree-ssa-sccvn.c | 2 +-
 gcc/tree-tailcall.c  | 6 +++---
 5 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/gcc/tree-nrv.c b/gcc/tree-nrv.c
index 9d17a104f34..df757f70e71 100644
--- a/gcc/tree-nrv.c
+++ b/gcc/tree-nrv.c
@@ -315,8 +315,8 @@ dest_safe_for_nrv_p (gcall *call)
   if (TREE_CODE (dest) == SSA_NAME)
     return true;
 
-  if (call_may_clobber_ref_p (call, dest)
-      || ref_maybe_used_by_stmt_p (call, dest))
+  if (call_may_clobber_ref_p (call, dest, false)
+      || ref_maybe_used_by_stmt_p (call, dest, false))
     return false;
 
   return true;
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index 97255987e79..ac7e020c5e2 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -3320,12 +3320,12 @@ call_may_clobber_ref_p_1 (gcall *call, ao_ref *ref, bool tbaa_p)
    return true, otherwise return false.  */
 
 bool
-call_may_clobber_ref_p (gcall *call, tree ref)
+call_may_clobber_ref_p (gcall *call, tree ref, bool tbaa_p)
 {
   bool res;
   ao_ref r;
   ao_ref_init (&r, ref);
-  res = call_may_clobber_ref_p_1 (call, &r, true);
+  res = call_may_clobber_ref_p_1 (call, &r, tbaa_p);
   if (res)
     ++alias_stats.call_may_clobber_ref_p_may_alias;
   else
diff --git a/gcc/tree-ssa-alias.h b/gcc/tree-ssa-alias.h
index 1dd02c0ea62..1561ead2941 100644
--- a/gcc/tree-ssa-alias.h
+++ b/gcc/tree-ssa-alias.h
@@ -128,7 +128,7 @@ extern bool ref_maybe_used_by_stmt_p (gimple *, ao_ref *, bool = true);
 extern bool stmt_may_clobber_global_p (gimple *);
 extern bool stmt_may_clobber_ref_p (gimple *, tree, bool = true);
 extern bool stmt_may_clobber_ref_p_1 (gimple *, ao_ref *, bool = true);
-extern bool call_may_clobber_ref_p (gcall *, tree);
+extern bool call_may_clobber_ref_p (gcall *, tree, bool = true);
 extern bool call_may_clobber_ref_p_1 (gcall *, ao_ref *, bool = true);
 extern bool stmt_kills_ref_p (gimple *, tree);
 extern bool stmt_kills_ref_p (gimple *, ao_ref *);
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 014b7bdfd01..c139adb6130 100644
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -2586,7 +2586,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
       if (valueized_anything)
 	{
 	  bool res = call_may_clobber_ref_p_1 (as_a <gcall *> (def_stmt),
-					       ref);
+					       ref, data->tbaa_p);
 	  for (unsigned i = 0; i < gimple_call_num_args (def_stmt); ++i)
 	    gimple_call_set_arg (def_stmt, i, oldargs[i]);
 	  if (!res)
diff --git a/gcc/tree-tailcall.c b/gcc/tree-tailcall.c
index d81e9213460..44643bef5f1 100644
--- a/gcc/tree-tailcall.c
+++ b/gcc/tree-tailcall.c
@@ -523,7 +523,7 @@ find_tail_calls (basic_block bb, struct tailcall **ret)
   tree result_decl = DECL_RESULT (cfun->decl);
   if (result_decl
       && may_be_aliased (result_decl)
-      && ref_maybe_used_by_stmt_p (call, result_decl))
+      && ref_maybe_used_by_stmt_p (call, result_decl, false))
     return;
 
   /* We found the call, check whether it is suitable.  */
@@ -597,8 +597,8 @@ find_tail_calls (basic_block bb, struct tailcall **ret)
       if (TREE_CODE (var) != PARM_DECL
 	  && auto_var_in_fn_p (var, cfun->decl)
 	  && may_be_aliased (var)
-	  && (ref_maybe_used_by_stmt_p (call, var)
-	      || call_may_clobber_ref_p (call, var)))
+	  && (ref_maybe_used_by_stmt_p (call, var, false)
+	      || call_may_clobber_ref_p (call, var, false)))
 	{
 	  if (!VAR_P (var))
 	    {