The following fixes PR66272.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk
sofar.
Richard.
2015-05-27 Richard Biener <rguent...@suse.de>
PR tree-optimization/66272
Revert parts of
2014-08-15 Richard Biener <rguent...@suse.de>
PR tree-optimization/62031
* tree-data-ref.c (dr_analyze_indices): Do not set
DR_UNCONSTRAINED_BASE.
(dr_may_alias_p): All indirect accesses have to go the
formerly DR_UNCONSTRAINED_BASE path.
* tree-data-ref.h (struct indices): Remove
unconstrained_base member.
(DR_UNCONSTRAINED_BASE): Remove.
* gcc.dg/torture/pr66272.c: New testcase.
Index: gcc/tree-data-ref.c
===================================================================
--- gcc/tree-data-ref.c (revision 223737)
+++ gcc/tree-data-ref.c (working copy)
@@ -1036,6 +1036,7 @@ dr_analyze_indices (struct data_referenc
base, memoff);
MR_DEPENDENCE_CLIQUE (ref) = MR_DEPENDENCE_CLIQUE (old);
MR_DEPENDENCE_BASE (ref) = MR_DEPENDENCE_BASE (old);
+ DR_UNCONSTRAINED_BASE (dr) = true;
access_fns.safe_push (access_fn);
}
}
@@ -1453,7 +1454,8 @@ dr_may_alias_p (const struct data_refere
offset/overlap based analysis but have to rely on points-to
information only. */
if (TREE_CODE (addr_a) == MEM_REF
- && TREE_CODE (TREE_OPERAND (addr_a, 0)) == SSA_NAME)
+ && (DR_UNCONSTRAINED_BASE (a)
+ || TREE_CODE (TREE_OPERAND (addr_a, 0)) == SSA_NAME))
{
/* For true dependences we can apply TBAA. */
if (flag_strict_aliasing
@@ -1469,7 +1471,8 @@ dr_may_alias_p (const struct data_refere
build_fold_addr_expr (addr_b));
}
else if (TREE_CODE (addr_b) == MEM_REF
- && TREE_CODE (TREE_OPERAND (addr_b, 0)) == SSA_NAME)
+ && (DR_UNCONSTRAINED_BASE (b)
+ || TREE_CODE (TREE_OPERAND (addr_b, 0)) == SSA_NAME))
{
/* For true dependences we can apply TBAA. */
if (flag_strict_aliasing
Index: gcc/tree-data-ref.h
===================================================================
--- gcc/tree-data-ref.h (revision 223737)
+++ gcc/tree-data-ref.h (working copy)
@@ -81,6 +81,10 @@ struct indices
/* A list of chrecs. Access functions of the indices. */
vec<tree> access_fns;
+
+ /* Whether BASE_OBJECT is an access representing the whole object
+ or whether the access could not be constrained. */
+ bool unconstrained_base;
};
struct dr_alias
@@ -129,6 +133,7 @@ struct data_reference
#define DR_STMT(DR) (DR)->stmt
#define DR_REF(DR) (DR)->ref
#define DR_BASE_OBJECT(DR) (DR)->indices.base_object
+#define DR_UNCONSTRAINED_BASE(DR) (DR)->indices.unconstrained_base
#define DR_ACCESS_FNS(DR) (DR)->indices.access_fns
#define DR_ACCESS_FN(DR, I) DR_ACCESS_FNS (DR)[I]
#define DR_NUM_DIMENSIONS(DR) DR_ACCESS_FNS (DR).length ()
Index: gcc/testsuite/gcc.dg/torture/pr66272.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr66272.c (revision 0)
+++ gcc/testsuite/gcc.dg/torture/pr66272.c (working copy)
@@ -0,0 +1,23 @@
+/* { dg-do run } */
+
+struct S
+{
+ int f0;
+ int f1;
+};
+
+int b;
+
+int main ()
+{
+ struct S a[2] = { 0 };
+ struct S d = { 0, 1 };
+ for (b = 0; b < 2; b++)
+ {
+ a[b] = d;
+ d = a[0];
+ }
+ if (d.f1 != 1)
+ __builtin_abort ();
+ return 0;
+}
