revert: re PR rtl-optimization/57381 (array of volatile pointers hangs gcc)

[gcc.git] / gcc / tree-ssa-sccvn.c

diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 0e7a74c2a9c3d0be641600c9020cefd9ce22c8f3..6886efbe3eb1f1f341e796c5c85abc58e870cec7 100644 (file)
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -1145,7 +1145,7 @@ vn_reference_fold_indirect (vec<vn_reference_op_s> *ops,
   addr_base = get_addr_base_and_unit_offset (TREE_OPERAND (op->op0, 0),
                                             &addr_offset);
   gcc_checking_assert (addr_base && TREE_CODE (addr_base) != MEM_REF);
-  if (addr_base != op->op0)
+  if (addr_base != TREE_OPERAND (op->op0, 0))
     {
       double_int off = tree_to_double_int (mem_op->op0);
       off = off.sext (TYPE_PRECISION (TREE_TYPE (mem_op->op0)));
@@ -2608,6 +2608,7 @@ static inline bool
 set_ssa_val_to (tree from, tree to)
 {
   tree currval = SSA_VAL (from);
+  HOST_WIDE_INT toff, coff;
 
   if (from != to)
     {
@@ -2643,7 +2644,17 @@ set_ssa_val_to (tree from, tree to)
       print_generic_expr (dump_file, to, 0);
     }
 
-  if (currval != to  && !operand_equal_p (currval, to, OEP_PURE_SAME))
+  if (currval != to
+      && !operand_equal_p (currval, to, 0)
+      /* ???  For addresses involving volatile objects or types operand_equal_p
+         does not reliably detect ADDR_EXPRs as equal.  We know we are only
+        getting invariant gimple addresses here, so can use
+        get_addr_base_and_unit_offset to do this comparison.  */
+      && !(TREE_CODE (currval) == ADDR_EXPR
+          && TREE_CODE (to) == ADDR_EXPR
+          && (get_addr_base_and_unit_offset (TREE_OPERAND (currval, 0), &coff)
+              == get_addr_base_and_unit_offset (TREE_OPERAND (to, 0), &toff))
+          && coff == toff))
     {
       VN_INFO (from)->valnum = to;
       if (dump_file && (dump_flags & TDF_DETAILS))