Expand TMR fixup when we end up with a (void *)0 base

When create_mem_ref falls back to a (void *)0 base address we
currently only fall back to LEA plus indirection when the target
can use a second index register.  But we also need to do this
if there's a scaled by one index.  Or rather always to be safe.

	* tree-ssa-loop-ivopts.cc (rewrite_use_address): Always
	avoid TARGET_MEM_REF with a base of zero.
	* tree-ssa-sccvn.cc (vn_reference_maybe_forwprop_address): Do
	not forward TARGET_MEM_REF addresses.

diff --git a/gcc/tree-ssa-loop-ivopts.cc b/gcc/tree-ssa-loop-ivopts.cc
index 4ca5532518875d2ddfb56e9761eada0e7cf97db2..f8dfc77de4ae2515efe883b260747d44a857c4c0 100644 (file)
--- a/gcc/tree-ssa-loop-ivopts.cc
+++ b/gcc/tree-ssa-loop-ivopts.cc
@@ -7639,11 +7639,10 @@ rewrite_use_address (struct ivopts_data *data,
   else
     {
       /* When we end up confused enough and have no suitable base but
-        stuffed everything to index2 use a LEA for the address and
+        stuffed everything to indexes use a LEA for the address and
         create a plain MEM_REF to avoid basing a memory reference
         on address zero which create_mem_ref_raw does as fallback.  */
       if (TREE_CODE (ref) == TARGET_MEM_REF
-         && TMR_INDEX2 (ref) != NULL_TREE
          && integer_zerop (TREE_OPERAND (ref, 0)))
        {
          ref = fold_build1 (ADDR_EXPR, TREE_TYPE (TREE_OPERAND (ref, 0)), ref);

diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc
index 98b837be01d0af217170618093f0eb93edf44afa..a95350abccbf4725c8798b3d34e08e0a0e6b5527 100644 (file)
--- a/gcc/tree-ssa-sccvn.cc
+++ b/gcc/tree-ssa-sccvn.cc
@@ -1507,6 +1507,9 @@ vn_reference_maybe_forwprop_address (vec<vn_reference_op_s> *ops,
                      = wide_int_to_tree (TREE_TYPE (mem_op->op0),
                                          wi::to_poly_wide (new_mem_op->op0));
                }
+             /* Do not forward addresses of TARGET_MEM_REF.  */
+             else if (tem[0].opcode == TARGET_MEM_REF)
+               return changed;
              else
                gcc_assert (tem.last ().opcode == STRING_CST);
              ops->pop ();