Add alias disambiguation for vectorizer load/store IFNs

The following adds support for MASK_STORE, MASK_LOAD and friends
to call_may_clobber_ref_p and ref_maybe_used_by_call_p.  Since
they all use a special argument to specify TBAA they are not really
suited for fnspec handling thus the manual support.

	* tree-ssa-alias.cc (ref_maybe_used_by_call_p_1): Special-case
	store internal functions and IFN_MASK_LOAD, IFN_LEN_LOAD
	and IFN_MASK_LOAD_LANES.
	(call_may_clobber_ref_p_1): Special-case IFN_MASK_STORE,
	IFN_LEN_STORE and IFN_MASK_STORE_LANES.

diff --git a/gcc/tree-ssa-alias.cc b/gcc/tree-ssa-alias.cc
index 782266bdad8ab0625ed038d93d9522fb8ffb508f..390cd875074effb52dabdc42a0d5b0c2c1fa0449 100644 (file)
--- a/gcc/tree-ssa-alias.cc
+++ b/gcc/tree-ssa-alias.cc
@@ -47,6 +47,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "print-tree.h"
 #include "tree-ssa-alias-compare.h"
 #include "builtins.h"
+#include "internal-fn.h"
 
 /* Broad overview of how alias analysis on gimple works:
 
@@ -2793,8 +2794,38 @@ ref_maybe_used_by_call_p_1 (gcall *call, ao_ref *ref, bool tbaa_p)
   if (ref->volatile_p)
     return true;
 
-  callee = gimple_call_fndecl (call);
+  if (gimple_call_internal_p (call))
+    switch (gimple_call_internal_fn (call))
+      {
+      case IFN_MASK_STORE:
+      case IFN_SCATTER_STORE:
+      case IFN_MASK_SCATTER_STORE:
+      case IFN_LEN_STORE:
+       return false;
+      case IFN_MASK_STORE_LANES:
+       goto process_args;
+      case IFN_MASK_LOAD:
+      case IFN_LEN_LOAD:
+      case IFN_MASK_LOAD_LANES:
+       {
+         ao_ref rhs_ref;
+         tree lhs = gimple_call_lhs (call);
+         if (lhs)
+           {
+             ao_ref_init_from_ptr_and_size (&rhs_ref,
+                                            gimple_call_arg (call, 0),
+                                            TYPE_SIZE_UNIT (TREE_TYPE (lhs)));
+             rhs_ref.ref_alias_set = rhs_ref.base_alias_set
+               = tbaa_p ? get_deref_alias_set (TREE_TYPE
+                                       (gimple_call_arg (call, 1))) : 0;
+             return refs_may_alias_p_1 (ref, &rhs_ref, tbaa_p);
+           }
+         break;
+       }
+      default:;
+      }
 
+  callee = gimple_call_fndecl (call);
   if (callee != NULL_TREE)
     {
       struct cgraph_node *node = cgraph_node::get (callee);
@@ -3005,7 +3036,7 @@ call_may_clobber_ref_p_1 (gcall *call, ao_ref *ref, bool tbaa_p)
       & (ECF_PURE|ECF_CONST|ECF_LOOPING_CONST_OR_PURE|ECF_NOVOPS))
     return false;
   if (gimple_call_internal_p (call))
-    switch (gimple_call_internal_fn (call))
+    switch (auto fn = gimple_call_internal_fn (call))
       {
        /* Treat these internal calls like ECF_PURE for aliasing,
           they don't write to any memory the program should care about.
@@ -3018,6 +3049,20 @@ call_may_clobber_ref_p_1 (gcall *call, ao_ref *ref, bool tbaa_p)
       case IFN_UBSAN_PTR:
       case IFN_ASAN_CHECK:
        return false;
+      case IFN_MASK_STORE:
+      case IFN_LEN_STORE:
+      case IFN_MASK_STORE_LANES:
+       {
+         tree rhs = gimple_call_arg (call,
+                                     internal_fn_stored_value_index (fn));
+         ao_ref lhs_ref;
+         ao_ref_init_from_ptr_and_size (&lhs_ref, gimple_call_arg (call, 0),
+                                        TYPE_SIZE_UNIT (TREE_TYPE (rhs)));
+         lhs_ref.ref_alias_set = lhs_ref.base_alias_set
+           = tbaa_p ? get_deref_alias_set
+                                  (TREE_TYPE (gimple_call_arg (call, 1))) : 0;
+         return refs_may_alias_p_1 (ref, &lhs_ref, tbaa_p);
+       }
       default:
        break;
       }