This fixes PR51245 - we fail to account for already existing VNs
when we discover translated constants in vn_reference_lookup_3.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2011-12-06 Richard Guenther <rguent...@suse.de>
PR tree-optimization/51245
* tree-ssa-sccvn.c (vn_reference_lookup_or_insert_constant_for_pieces):
New function.
(vn_reference_lookup_3): Use it. Properly valueize all refs
we create.
* gcc.dg/torture/pr51245.c: New testcase.
Index: gcc/tree-ssa-sccvn.c
===================================================================
--- gcc/tree-ssa-sccvn.c (revision 182010)
+++ gcc/tree-ssa-sccvn.c (working copy)
@@ -1337,6 +1337,33 @@ vn_reference_lookup_2 (ao_ref *op ATTRIB
return NULL;
}
+/* Lookup an existing or insert a new vn_reference entry into the
+ value table for the VUSE, SET, TYPE, OPERANDS reference which
+ has the constant value CST. */
+
+static vn_reference_t
+vn_reference_lookup_or_insert_constant_for_pieces (tree vuse,
+ alias_set_type set,
+ tree type,
+ VEC (vn_reference_op_s,
+ heap) *operands,
+ tree cst)
+{
+ struct vn_reference_s vr1;
+ vn_reference_t result;
+ vr1.vuse = vuse;
+ vr1.operands = operands;
+ vr1.type = type;
+ vr1.set = set;
+ vr1.hashcode = vn_reference_compute_hash (&vr1);
+ if (vn_reference_lookup_1 (&vr1, &result))
+ return result;
+ return vn_reference_insert_pieces (vuse, set, type,
+ VEC_copy (vn_reference_op_s, heap,
+ operands), cst,
+ get_or_alloc_constant_value_id (cst));
+}
+
/* Callback for walk_non_aliased_vuses. Tries to perform a lookup
from the statement defining VUSE and if not successful tries to
translate *REFP and VR_ through an aggregate copy at the defintion
@@ -1416,11 +1443,8 @@ vn_reference_lookup_3 (ao_ref *ref, tree
&& offset2 + size2 >= offset + maxsize)
{
tree val = build_zero_cst (vr->type);
- unsigned int value_id = get_or_alloc_constant_value_id (val);
- return vn_reference_insert_pieces (vuse, vr->set, vr->type,
- VEC_copy (vn_reference_op_s,
- heap, vr->operands),
- val, value_id);
+ return vn_reference_lookup_or_insert_constant_for_pieces
+ (vuse, vr->set, vr->type, vr->operands, val);
}
}
@@ -1440,11 +1464,8 @@ vn_reference_lookup_3 (ao_ref *ref, tree
&& offset2 + size2 >= offset + maxsize)
{
tree val = build_zero_cst (vr->type);
- unsigned int value_id = get_or_alloc_constant_value_id (val);
- return vn_reference_insert_pieces (vuse, vr->set, vr->type,
- VEC_copy (vn_reference_op_s,
- heap, vr->operands),
- val, value_id);
+ return vn_reference_lookup_or_insert_constant_for_pieces
+ (vuse, vr->set, vr->type, vr->operands, val);
}
}
@@ -1484,13 +1505,8 @@ vn_reference_lookup_3 (ao_ref *ref, tree
/ BITS_PER_UNIT),
ref->size / BITS_PER_UNIT);
if (val)
- {
- unsigned int value_id = get_or_alloc_constant_value_id (val);
- return vn_reference_insert_pieces
- (vuse, vr->set, vr->type,
- VEC_copy (vn_reference_op_s, heap, vr->operands),
- val, value_id);
- }
+ return vn_reference_lookup_or_insert_constant_for_pieces
+ (vuse, vr->set, vr->type, vr->operands, val);
}
}
}
@@ -1543,13 +1559,8 @@ vn_reference_lookup_3 (ao_ref *ref, tree
}
}
if (val)
- {
- unsigned int value_id = get_or_alloc_constant_value_id (val);
- return vn_reference_insert_pieces
- (vuse, vr->set, vr->type,
- VEC_copy (vn_reference_op_s, heap, vr->operands),
- val, value_id);
- }
+ return vn_reference_lookup_or_insert_constant_for_pieces
+ (vuse, vr->set, vr->type, vr->operands, val);
}
}
}
@@ -1635,6 +1646,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree
FOR_EACH_VEC_ELT (vn_reference_op_s, rhs, j, vro)
VEC_replace (vn_reference_op_s, vr->operands, i + 1 + j, vro);
VEC_free (vn_reference_op_s, heap, rhs);
+ vr->operands = valueize_refs (vr->operands);
vr->hashcode = vn_reference_compute_hash (vr);
/* Adjust *ref from the new operands. */
Index: gcc/testsuite/gcc.dg/torture/pr51245.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr51245.c (revision 0)
+++ gcc/testsuite/gcc.dg/torture/pr51245.c (revision 0)
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+
+struct S { int s; } a, *b, **c;
+int d;
+
+struct S
+foo (void)
+{
+ struct S s = { 0 }, *e = &a;
+ if (d)
+ **c = *b;
+ while (1)
+ {
+ *b = s;
+ *e = *b;
+ if (a.s)
+ break;
+ }
+ return **c;
+}
