Hi!
This simple patch improves the f3 function in the testcase below,
a parameter with TYPE_RESTRICT REFERENCE_TYPE IMHO can be safely treated
like the DECL_BY_REFERENCE case where the source actually didn't contain
a reference, but compiler created it anyway. If source contains &__restrict
parameter, the parameter again points to a chunk of (for the function
global) restrict memory that nothing inside of the function should access
otherwise than through this parameter or pointers derived from it.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2011-09-23 Jakub Jelinek <ja...@redhat.com>
* tree-ssa-structalias.c (intra_create_variable_infos): Treat
TYPE_RESTRICT REFERENCE_TYPE parameters like restricted
DECL_BY_REFERENCE parameters.
* g++.dg/tree-ssa/restrict2.C: New test.
--- gcc/tree-ssa-structalias.c.jj 2011-09-15 12:18:37.000000000 +0200
+++ gcc/tree-ssa-structalias.c 2011-09-23 15:36:23.000000000 +0200
@@ -5589,10 +5589,11 @@ intra_create_variable_infos (void)
varinfo_t p;
/* For restrict qualified pointers to objects passed by
- reference build a real representative for the pointed-to object. */
- if (DECL_BY_REFERENCE (t)
- && POINTER_TYPE_P (TREE_TYPE (t))
- && TYPE_RESTRICT (TREE_TYPE (t)))
+ reference build a real representative for the pointed-to object.
+ Treat restrict qualified references the same. */
+ if (TYPE_RESTRICT (TREE_TYPE (t))
+ && ((DECL_BY_REFERENCE (t) && POINTER_TYPE_P (TREE_TYPE (t)))
+ || TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE))
{
struct constraint_expr lhsc, rhsc;
varinfo_t vi;
--- gcc/testsuite/g++.dg/tree-ssa/restrict2.C.jj 2011-09-23
16:11:27.000000000 +0200
+++ gcc/testsuite/g++.dg/tree-ssa/restrict2.C 2011-09-23 16:10:28.000000000
+0200
@@ -0,0 +1,62 @@
+// { dg-do compile }
+// { dg-options "-O2 -fdump-tree-optimized" }
+
+struct S { int *__restrict p; int q; };
+S s;
+
+int
+f1 (S x, S y)
+{
+ x.p[0] = 1;
+ y.p[0] = 0;
+// { dg-final { scan-tree-dump-times "return 1" 1 "optimized" } }
+ return x.p[0];
+}
+
+int
+f2 (S x)
+{
+ x.p[0] = 2;
+ s.p[0] = 0;
+// { dg-final { scan-tree-dump-times "return 2" 1 "optimized" } }
+ return x.p[0];
+}
+
+int
+f3 (S &__restrict x, S &__restrict y)
+{
+ x.p[0] = 3;
+ y.p[0] = 0;
+// { dg-final { scan-tree-dump-times "return 3" 1 "optimized" } }
+ return x.p[0];
+}
+
+int
+f4 (S &x, S &y)
+{
+ x.p[0] = 4;
+ y.p[0] = 0;
+// { dg-final { scan-tree-dump-times "return 4" 0 "optimized" } }
+ return x.p[0];
+}
+
+int
+f5 (S *__restrict x, S *__restrict y)
+{
+ x->p[0] = 5;
+ y->p[0] = 0;
+// We might handle this some day
+// { dg-final { scan-tree-dump-times "return 5" 0 "optimized" } }
+ return x->p[0];
+}
+
+int
+f6 (S *x, S *y)
+{
+ x->p[0] = 6;
+ y->p[0] = 0;
+// { dg-final { scan-tree-dump-times "return 6" 0 "optimized" } }
+ return x->p[0];
+}
+
+// { dg-final { cleanup-tree-dump "optimized" } }
Jakub
