re PR middle-end/42834 (memcpy folding overeager)

2010-07-01  Richard Guenther  <rguenther@suse.de>

	PR middle-end/42834
	PR middle-end/44468
	* doc/gimple.texi (is_gimple_mem_ref_addr): Document.
	* doc/generic.texi (References to storage): Document MEM_REF.
	* tree-pretty-print.c (dump_generic_node): Handle MEM_REF.
	(print_call_name): Likewise.
	* tree.c (recompute_tree_invariant_for_addr_expr): Handle MEM_REF.
	(build_simple_mem_ref_loc): New function.
	(mem_ref_offset): Likewise.
	* tree.h (build_simple_mem_ref_loc): Declare.
	(build_simple_mem_ref): Define.
	(mem_ref_offset): Declare.
	* fold-const.c: Include tree-flow.h.
	(operand_equal_p): Handle MEM_REF.
	(build_fold_addr_expr_with_type_loc): Likewise.
	(fold_comparison): Likewise.
	(fold_unary_loc): Fold
	VIEW_CONVERT_EXPR <T1, MEM_REF <T2, ...>> to MEM_REF <T1, ...>.
	(fold_binary_loc): Fold MEM[&MEM[p, CST1], CST2] to MEM[p, CST1 + CST2],
	fold MEM[&a.b, CST2] to MEM[&a, offsetof (a, b) + CST2].
	* tree-ssa-alias.c (ptr_deref_may_alias_decl_p): Handle MEM_REF.
	(ptr_deref_may_alias_ref_p_1): Likewise.
	(ao_ref_base_alias_set): Properly differentiate base object for
	offset and TBAA.
	(ao_ref_init_from_ptr_and_size): Use MEM_REF.
	(indirect_ref_may_alias_decl_p): Handle MEM_REFs properly.
	(indirect_refs_may_alias_p): Likewise.
	(refs_may_alias_p_1): Likewise.  Remove pointer SSA name def
	chasing code.
	(ref_maybe_used_by_call_p_1): Handle MEM_REF.
	(call_may_clobber_ref_p_1): Likewise.
	* dwarf2out.c (loc_list_from_tree): Handle MEM_REF.
	* expr.c (expand_assignment): Handle MEM_REF.
	(store_expr): Handle MEM_REFs from STRING_CSTs.
	(store_field): If expanding a MEM_REF of a non-addressable
	decl use bitfield operations.
	(get_inner_reference): Handle MEM_REF.
	(expand_expr_addr_expr_1): Likewise.
	(expand_expr_real_1): Likewise.
	* tree-eh.c (tree_could_trap_p): Handle MEM_REF.
	* alias.c (ao_ref_from_mem): Handle MEM_REF.
	(get_alias_set): Likewise.  Properly handle VIEW_CONVERT_EXPRs.
	* tree-data-ref.c (dr_analyze_innermost): Handle MEM_REF.
	(dr_analyze_indices): Likewise.
	(dr_analyze_alias): Likewise.
	(object_address_invariant_in_loop_p): Likewise.
	* gimplify.c (mark_addressable): Handle MEM_REF.
	(gimplify_cond_expr): Build MEM_REFs.
	(gimplify_modify_expr_to_memcpy): Likewise.
	(gimplify_init_ctor_preeval_1): Handle MEM_REF.
	(gimple_fold_indirect_ref): Adjust.
	(gimplify_expr): Handle MEM_REF.  Gimplify INDIRECT_REF to MEM_REF.
	* tree.def (MEM_REF): New tree code.
	* tree-dfa.c: Include toplev.h.
	(get_ref_base_and_extent): Handle MEM_REF.
	(get_addr_base_and_unit_offset): New function.
	* emit-rtl.c (set_mem_attributes_minus_bitpos): Handle MEM_REF.
	* gimple-fold.c (may_propagate_address_into_dereference): Handle
	MEM_REF.
	(maybe_fold_offset_to_array_ref): Allow possibly out-of bounds
	accesses if the array has just one dimension.  Remove always true
	parameter.  Do not require type compatibility here.
	(maybe_fold_offset_to_component_ref): Remove.
	(maybe_fold_stmt_indirect): Remove.
	(maybe_fold_reference): Remove INDIRECT_REF handling.
	Fold back to non-MEM_REF.
	(maybe_fold_offset_to_address): Simplify.  Deal with type
	mismatches here.
	(maybe_fold_reference): Likewise.
	(maybe_fold_stmt_addition): Likewise.  Also handle
	&ARRAY + I in addition to &ARRAY[0] + I.
	(fold_gimple_assign): Handle ADDR_EXPR of MEM_REFs.
	(gimple_get_relevant_ref_binfo): Handle MEM_REF.
	* cfgexpand.c (expand_debug_expr): Handle MEM_REF.
	* tree-ssa.c (useless_type_conversion_p): Make most pointer
	conversions useless.
	(warn_uninitialized_var): Handle MEM_REF.
	(maybe_rewrite_mem_ref_base): New function.
	(execute_update_addresses_taken): Implement re-writing of MEM_REFs
	to SSA form.
	* tree-inline.c (remap_gimple_op_r): Handle MEM_REF, remove
	INDIRECT_REF handling.
	(copy_tree_body_r): Handle MEM_REF.
	* gimple.c (is_gimple_addressable): Adjust.
	(is_gimple_address): Likewise.
	(is_gimple_invariant_address): ADDR_EXPRs of MEM_REFs with
	invariant base are invariant.
	(is_gimple_min_lval): Adjust.
	(is_gimple_mem_ref_addr): New function.
	(get_base_address): Handle MEM_REF.
	(count_ptr_derefs): Likewise.
	(get_base_loadstore): Likewise.
	* gimple.h (is_gimple_mem_ref_addr): Declare.
	(gimple_call_fndecl): Handle invariant MEM_REF addresses.
	* tree-cfg.c (verify_address): New function, split out from ...
	(verify_expr): ... here.  Use for verifying ADDR_EXPRs and
	the address operand of MEM_REFs.  Verify MEM_REFs.  Reject
	INDIRECT_REFs.
	(verify_types_in_gimple_min_lval): Handle MEM_REF.  Disallow
	INDIRECT_REF.  Allow conversions.
	(verify_types_in_gimple_reference): Verify VIEW_CONVERT_EXPR of
	a register does not change its size.
	(verify_types_in_gimple_reference): Verify MEM_REF.
	(verify_gimple_assign_single): Disallow INDIRECT_REF.
	Handle MEM_REF.
	* tree-ssa-operands.c (opf_non_addressable, opf_not_non_addressable):
	New.
	(mark_address_taken): Handle MEM_REF.
	(get_indirect_ref_operands): Pass through opf_not_non_addressable.
	(get_asm_expr_operands): Pass opf_not_non_addressable.
	(get_expr_operands): Handle opf_[not_]non_addressable.
	Handle MEM_REF.  Remove INDIRECT_REF handling.
	* tree-vrp.c: (check_array_ref): Handle MEM_REF.
	(search_for_addr_array): Likewise.
	(check_array_bounds): Likewise.
	(vrp_stmt_computes_nonzero): Adjust for MEM_REF.
	* tree-ssa-loop-im.c (for_each_index): Handle MEM_REF.
	(ref_always_accessed_p): Likewise.
	(gen_lsm_tmp_name): Likewise.  Handle ADDR_EXPR.
	* tree-complex.c (extract_component): Do not handle INDIRECT_REF.
	Handle MEM_REF.
	* cgraphbuild.c (mark_load): Properly check for NULL result
	from get_base_address.
	(mark_store): Likewise.
	* tree-ssa-loop-niter.c (array_at_struct_end_p): Handle MEM_REF.
	* tree-loop-distribution.c (generate_builtin): Exchange INDIRECT_REF
	handling for MEM_REF.
	* tree-scalar-evolution.c (follow_ssa_edge_expr): Handle
	&MEM[ptr + CST] similar to POINTER_PLUS_EXPR.
	* builtins.c (stabilize_va_list_loc): Use the function ABI
	valist type if we couldn't canonicalize the argument type.
	Always dereference with the canonical va-list type.
	(maybe_emit_free_warning): Handle MEM_REF.
	(fold_builtin_memory_op): Simplify and handle MEM_REFs in folding
	memmove to memcpy.
	* builtins.c (fold_builtin_memory_op): Use ref-all types
	for all memcpy foldings.
	* omp-low.c (build_receiver_ref): Adjust for MEM_REF.
	(build_outer_var_ref): Likewise.
	(scan_omp_1_op): Likewise.
	(lower_rec_input_clauses): Likewise.
	(lower_lastprivate_clauses): Likewise.
	(lower_reduction_clauses): Likewise.
	(lower_copyprivate_clauses): Likewise.
	(expand_omp_atomic_pipeline): Likewise.
	(expand_omp_atomic_mutex): Likewise.
	(create_task_copyfn): Likewise.
	* tree-ssa-sccvn.c (copy_reference_ops_from_ref): Handle MEM_REF.
	Remove old union trick.  Initialize constant offsets.
	(ao_ref_init_from_vn_reference): Likewise.  Do not handle
	INDIRECT_REF.  Init base_alias_set properly.
	(vn_reference_lookup_3): Replace INDIRECT_REF handling with
	MEM_REF.
	(vn_reference_fold_indirect): Adjust for MEM_REFs.
	(valueize_refs): Fold MEM_REFs.  Re-evaluate constant offset
	for ARRAY_REFs.
	(may_insert): Remove.
	(visit_reference_op_load): Do not test may_insert.
	(run_scc_vn): Remove parameter, do not fiddle with may_insert.
	* tree-ssa-sccvn.h (struct vn_reference_op_struct): Add
	a field to store the constant offset this op applies.
	(run_scc_vn): Adjust prototype.
	* cgraphunit.c (thunk_adjust): Adjust for MEM_REF.
	* tree-ssa-ccp.c (ccp_fold): Replace INDIRECT_REF folding with
	MEM_REF.  Propagate &foo + CST as &MEM[&foo, CST].  Do not
	bother about volatile qualifiers on pointers.
	(fold_const_aggregate_ref): Handle MEM_REF, do not handle INDIRECT_REF.
	* tree-ssa-loop-ivopts.c
	* tree-ssa-loop-ivopts.c (determine_base_object): Adjust
	for MEM_REF.
	(strip_offset_1): Likewise.
	(find_interesting_uses_address): Replace INDIRECT_REF handling with
	MEM_REF handling.
	(get_computation_cost_at): Likewise.
	* ipa-pure-const.c (check_op): Handle MEM_REF.
	* tree-stdarg.c (check_all_va_list_escapes): Adjust for MEM_REF.
	* tree-ssa-sink.c (is_hidden_global_store): Handle MEM_REF
	and constants.
	* ipa-inline.c (likely_eliminated_by_inlining_p): Handle MEM_REF.
	* tree-parloops.c (take_address_of): Adjust for MEM_REF.
	(eliminate_local_variables_1): Likewise.
	(create_call_for_reduction_1): Likewise.
	(create_loads_for_reductions): Likewise.
	(create_loads_and_stores_for_name): Likewise.
	* matrix-reorg.c (may_flatten_matrices_1): Sanitize.
	(ssa_accessed_in_tree): Handle MEM_REF.
	(ssa_accessed_in_assign_rhs): Likewise.
	(update_type_size): Likewise.
	(analyze_accesses_for_call_stmt): Likewise.
	(analyze_accesses_for_assign_stmt): Likewise.
	(transform_access_sites): Likewise.
	(transform_allocation_sites): Likewise.
	* tree-affine.c (tree_to_aff_combination): Handle MEM_REF.
	* tree-vect-data-refs.c (vect_create_addr_base_for_vector_ref): Do
	not handle INDIRECT_REF.
	* tree-ssa-phiopt.c (add_or_mark_expr): Handle MEM_REF.
	(cond_store_replacement): Likewise.
	* tree-ssa-pre.c (create_component_ref_by_pieces_1): Handle
	MEM_REF, no not handle INDIRECT_REFs.
	(insert_into_preds_of_block): Properly initialize avail.
	(phi_translate_1): Fold MEM_REFs.  Re-evaluate constant offset
	for ARRAY_REFs.  Properly handle reference lookups that
	require a bit re-interpretation.
	(can_PRE_operation): Do not handle INDIRECT_REF.  Handle MEM_REF.
	* tree-sra.c
	* tree-sra.c (build_access_from_expr_1): Handle MEM_REF.
	(build_ref_for_offset_1): Remove.
	(build_ref_for_offset): Build MEM_REFs.
	(gate_intra_sra): Disable for now.
	(sra_ipa_modify_expr): Handle MEM_REF.
	(ipa_early_sra_gate): Disable for now.
	* tree-sra.c (create_access): Swap INDIRECT_REF handling for
	MEM_REF handling.
	(disqualify_base_of_expr): Likewise.
	(ptr_parm_has_direct_uses): Swap INDIRECT_REF handling for
	MEM_REF handling.
	(sra_ipa_modify_expr): Remove INDIRECT_REF handling.
	Use mem_ref_offset.  Remove bogus folding.
	(build_access_from_expr_1): Properly handle MEM_REF for
	non IPA-SRA.
	(make_fancy_name_1): Add support for MEM_REF.
	* tree-predcom.c (ref_at_iteration): Handle MEM_REFs.
	* tree-mudflap.c (mf_xform_derefs_1): Adjust for MEM_REF.
	* ipa-prop.c (compute_complex_assign_jump_func): Handle MEM_REF.
	(compute_complex_ancestor_jump_func): Likewise.
	(ipa_analyze_virtual_call_uses): Likewise.
	* tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Replace
	INDIRECT_REF folding with more generalized MEM_REF folding.
	(tree_ssa_forward_propagate_single_use_vars): Adjust accordingly.
	(forward_propagate_addr_into_variable_array_index): Also handle
	&ARRAY + I in addition to &ARRAY[0] + I.
	* tree-ssa-dce.c (ref_may_be_aliased): Handle MEM_REF.
	* tree-ssa-ter.c (find_replaceable_in_bb): Avoid TER if that
	creates assignments with overlap.
	* tree-nested.c (get_static_chain): Adjust for MEM_REF.
	(get_frame_field): Likewise.
	(get_nonlocal_debug_decl): Likewise.
	(convert_nonlocal_reference_op): Likewise.
	(struct nesting_info): Add mem_refs pointer-set.
	(create_nesting_tree): Allocate it.
	(convert_local_reference_op): Insert to be folded mem-refs.
	(fold_mem_refs): New function.
	(finalize_nesting_tree_1): Perform defered folding of mem-refs 
	(free_nesting_tree): Free the pointer-set.
	* tree-vect-stmts.c (vectorizable_store): Adjust for MEM_REF.
	(vectorizable_load): Likewise.
	* tree-ssa-phiprop.c (phiprop_insert_phi): Adjust for MEM_REF.
	(propagate_with_phi): Likewise.
	* tree-object-size.c (addr_object_size): Handle MEM_REFs
	instead of INDIRECT_REFs.
	(compute_object_offset): Handle MEM_REF.
	(plus_stmt_object_size): Handle MEM_REF.
	(collect_object_sizes_for): Dispatch to plus_stmt_object_size
	for &MEM_REF.
	* tree-flow.h (get_addr_base_and_unit_offset): Declare.
	(symbol_marked_for_renaming): Likewise.
	* Makefile.in (tree-dfa.o): Add $(TOPLEV_H).
	(fold-const.o): Add $(TREE_FLOW_H).
	* tree-ssa-structalias.c (get_constraint_for_1): Handle MEM_REF.
	(find_func_clobbers): Likewise.
	* ipa-struct-reorg.c (decompose_indirect_ref_acc): Handle MEM_REF.
	(decompose_access): Likewise.
	(replace_field_acc): Likewise.
	(replace_field_access_stmt): Likewise.
	(insert_new_var_in_stmt): Likewise.
	(get_stmt_accesses): Likewise.
	(reorg_structs_drive): Disable.
	* config/i386/i386.c (ix86_va_start): Adjust for MEM_REF.
	(ix86_canonical_va_list_type): Likewise.

	cp/
	* cp-gimplify.c (cp_gimplify_expr): Open-code the rhs
	predicate we are looking for, allow non-gimplified
	INDIRECT_REFs.

	testsuite/
	* gcc.c-torture/execute/20100316-1.c: New testcase.
	* gcc.c-torture/execute/pr44468.c: Likewise.
	* gcc.c-torture/compile/20100609-1.c: Likewise.
	* gcc.dg/volatile2.c: Adjust.
	* gcc.dg/plugin/selfassign.c: Likewise.
	* gcc.dg/pr36902.c: Likewise.
	* gcc.dg/tree-ssa/foldaddr-2.c: Remove.
	* gcc.dg/tree-ssa/foldaddr-3.c: Likewise.
	* gcc.dg/tree-ssa/forwprop-8.c: Adjust.
	* gcc.dg/tree-ssa/pr17141-1.c: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-13.c: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-14.c: Likewise.
	* gcc.dg/tree-ssa/ssa-ccp-21.c: Likewise.
	* gcc.dg/tree-ssa/pta-ptrarith-1.c: Likewise.
	* gcc.dg/tree-ssa/20030807-7.c: Likewise.
	* gcc.dg/tree-ssa/forwprop-10.c: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-1.c: Likewise.
	* gcc.dg/tree-ssa/pta-ptrarith-2.c: Likewise.
	* gcc.dg/tree-ssa/ssa-ccp-23.c: Likewise.
	* gcc.dg/tree-ssa/forwprop-1.c: Likewise.
	* gcc.dg/tree-ssa/forwprop-2.c: Likewise.
	* gcc.dg/tree-ssa/struct-aliasing-1.c: Likewise.
	* gcc.dg/tree-ssa/ssa-ccp-25.c: Likewise.
	* gcc.dg/tree-ssa/ssa-pre-26.c: Likewise.
	* gcc.dg/tree-ssa/struct-aliasing-2.c: Likewise.
	* gcc.dg/tree-ssa/ssa-ccp-26.c: Likewise.
	* gcc.dg/tree-ssa/ssa-sccvn-4.c: Likewise.
	* gcc.dg/tree-ssa/ssa-pre-7.c: Likewise.
	* gcc.dg/tree-ssa/forwprop-5.c: Likewise.
	* gcc.dg/struct/w_prof_two_strs.c: XFAIL.
	* gcc.dg/struct/wo_prof_escape_arg_to_local.c: Likewise.
	* gcc.dg/struct/wo_prof_global_var.c: Likewise.
	* gcc.dg/struct/wo_prof_malloc_size_var.c: Likewise.
	* gcc.dg/struct/w_prof_local_array.c: Likewise.
	* gcc.dg/struct/w_prof_single_str_global.c: Likewise.
	* gcc.dg/struct/wo_prof_escape_str_init.c: Likewise.
	* gcc.dg/struct/wo_prof_array_through_pointer.c: Likewise.
	* gcc.dg/struct/w_prof_global_array.c: Likewise.
	* gcc.dg/struct/wo_prof_array_field.c: Likewise.
	* gcc.dg/struct/wo_prof_single_str_local.c: Likewise.
	* gcc.dg/struct/w_prof_local_var.c: Likewise.
	* gcc.dg/struct/wo_prof_two_strs.c: Likewise.
	* gcc.dg/struct/wo_prof_empty_str.c: Likewise.
	* gcc.dg/struct/wo_prof_local_array.c: Likewise.
	* gcc.dg/struct/w_prof_global_var.c: Likewise.
	* gcc.dg/struct/wo_prof_single_str_global.c: Likewise.
	* gcc.dg/struct/wo_prof_escape_substr_value.c: Likewise.
	* gcc.dg/struct/wo_prof_global_array.c: Likewise.
	* gcc.dg/struct/wo_prof_escape_return.c: Likewise.
	* gcc.dg/struct/wo_prof_escape_substr_array.c: Likewise.
	* gcc.dg/struct/wo_prof_double_malloc.c: Likewise.
	* gcc.dg/struct/w_ratio_cold_str.c: Likewise.
	* gcc.dg/struct/wo_prof_escape_substr_pointer.c: Likewise.
	* gcc.dg/struct/wo_prof_local_var.c: Likewise.
	* gcc.dg/tree-prof/stringop-1.c: Adjust.
	* g++.dg/tree-ssa/pr31146.C: Likewise.
	* g++.dg/tree-ssa/copyprop-1.C: Likewise.
	* g++.dg/tree-ssa/pr33604.C: Likewise.
	* g++.dg/plugin/selfassign.c: Likewise.
	* gfortran.dg/array_memcpy_3.f90: Likewise.
	* gfortran.dg/array_memcpy_4.f90: Likewise.
	* c-c++-common/torture/pr42834.c: New testcase.

From-SVN: r161655

1 files changed, 96 insertions, 50 deletions

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index e1660a350ba..a9c93ac972d 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -110,10 +110,13 @@ mark_addressable (tree x)
 {
   while (handled_component_p (x))
     x = TREE_OPERAND (x, 0);
+  if (TREE_CODE (x) == MEM_REF
+      && TREE_CODE (TREE_OPERAND (x, 0)) == ADDR_EXPR)
+    x = TREE_OPERAND (TREE_OPERAND (x, 0), 0);
   if (TREE_CODE (x) != VAR_DECL
       && TREE_CODE (x) != PARM_DECL
       && TREE_CODE (x) != RESULT_DECL)
-    return ;
+    return;
   TREE_ADDRESSABLE (x) = 1;
 }
 
@@ -2961,7 +2964,7 @@ gimplify_cond_expr (tree *expr_p, gimple_seq *pre_p, fallback_t fallback)
 	    = build3 (COND_EXPR, type, TREE_OPERAND (expr, 0), then_, else_);
 
 	  tmp = create_tmp_var (type, "iftmp");
-	  result = build_fold_indirect_ref_loc (loc, tmp);
+	  result = build_simple_mem_ref_loc (loc, tmp);
 	}
 
       /* Build the new then clause, `tmp = then_;'.  But don't build the
@@ -3185,7 +3188,7 @@ gimplify_modify_expr_to_memcpy (tree *expr_p, tree size, bool want_value,
       gimple_call_set_lhs (gs, t);
       gimplify_seq_add_stmt (seq_p, gs);
 
-      *expr_p = build1 (INDIRECT_REF, TREE_TYPE (to), t);
+      *expr_p = build_simple_mem_ref (t);
       return GS_ALL_DONE;
     }
 
@@ -3269,13 +3272,16 @@ gimplify_init_ctor_preeval_1 (tree *tp, int *walk_subtrees, void *xdata)
   /* If the constructor component is indirect, determine if we have a
      potential overlap with the lhs.  The only bits of information we
      have to go on at this point are addressability and alias sets.  */
-  if (TREE_CODE (t) == INDIRECT_REF
+  if ((INDIRECT_REF_P (t)
+       || TREE_CODE (t) == MEM_REF)
       && (!data->lhs_base_decl || TREE_ADDRESSABLE (data->lhs_base_decl))
       && alias_sets_conflict_p (data->lhs_alias_set, get_alias_set (t)))
     return t;
 
   /* If the constructor component is a call, determine if it can hide a
-     potential overlap with the lhs through an INDIRECT_REF like above.  */
+     potential overlap with the lhs through an INDIRECT_REF like above.
+     ??? Ugh - this is completely broken.  In fact this whole analysis
+     doesn't look conservative.  */
   if (TREE_CODE (t) == CALL_EXPR)
     {
       tree type, fntype = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (t)));
@@ -4004,7 +4010,7 @@ gimplify_init_constructor (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
 tree
 gimple_fold_indirect_ref (tree t)
 {
-  tree type = TREE_TYPE (TREE_TYPE (t));
+  tree ptype = TREE_TYPE (t), type = TREE_TYPE (ptype);
   tree sub = t;
   tree subtype;
 
@@ -4047,51 +4053,52 @@ gimple_fold_indirect_ref (tree t)
         }
     }
 
-  /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */
+  /* *(p + CST) -> ...  */
   if (TREE_CODE (sub) == POINTER_PLUS_EXPR
       && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
     {
-      tree op00 = TREE_OPERAND (sub, 0);
-      tree op01 = TREE_OPERAND (sub, 1);
-      tree op00type;
+      tree addr = TREE_OPERAND (sub, 0);
+      tree off = TREE_OPERAND (sub, 1);
+      tree addrtype;
+
+      STRIP_NOPS (addr);
+      addrtype = TREE_TYPE (addr);
 
-      STRIP_NOPS (op00);
-      op00type = TREE_TYPE (op00);
-      if (TREE_CODE (op00) == ADDR_EXPR
-	  && TREE_CODE (TREE_TYPE (op00type)) == VECTOR_TYPE
-	  && useless_type_conversion_p (type, TREE_TYPE (TREE_TYPE (op00type))))
+      /* ((foo*)&vectorfoo)[1] -> BIT_FIELD_REF<vectorfoo,...> */
+      if (TREE_CODE (addr) == ADDR_EXPR
+	  && TREE_CODE (TREE_TYPE (addrtype)) == VECTOR_TYPE
+	  && useless_type_conversion_p (type, TREE_TYPE (TREE_TYPE (addrtype))))
 	{
-	  HOST_WIDE_INT offset = tree_low_cst (op01, 0);
-	  tree part_width = TYPE_SIZE (type);
-	  unsigned HOST_WIDE_INT part_widthi
-	    = tree_low_cst (part_width, 0) / BITS_PER_UNIT;
-	  unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT;
-	  tree index = bitsize_int (indexi);
-	  if (offset / part_widthi
-	      <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (op00type)))
-	    return fold_build3 (BIT_FIELD_REF, type, TREE_OPERAND (op00, 0),
-				part_width, index);
+          HOST_WIDE_INT offset = tree_low_cst (off, 0);
+          tree part_width = TYPE_SIZE (type);
+          unsigned HOST_WIDE_INT part_widthi
+            = tree_low_cst (part_width, 0) / BITS_PER_UNIT;
+          unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT;
+          tree index = bitsize_int (indexi);
+          if (offset / part_widthi
+              <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (addrtype)))
+            return fold_build3 (BIT_FIELD_REF, type, TREE_OPERAND (addr, 0),
+                                part_width, index);
 	}
-    }
 
-  /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
-  if (TREE_CODE (sub) == POINTER_PLUS_EXPR
-      && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
-    {
-      tree op00 = TREE_OPERAND (sub, 0);
-      tree op01 = TREE_OPERAND (sub, 1);
-      tree op00type;
+      /* ((foo*)&complexfoo)[1] -> __imag__ complexfoo */
+      if (TREE_CODE (addr) == ADDR_EXPR
+	  && TREE_CODE (TREE_TYPE (addrtype)) == COMPLEX_TYPE
+	  && useless_type_conversion_p (type, TREE_TYPE (TREE_TYPE (addrtype))))
+        {
+          tree size = TYPE_SIZE_UNIT (type);
+          if (tree_int_cst_equal (size, off))
+            return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (addr, 0));
+        }
 
-      STRIP_NOPS (op00);
-      op00type = TREE_TYPE (op00);
-      if (TREE_CODE (op00) == ADDR_EXPR
-	  && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
-	  && useless_type_conversion_p (type, TREE_TYPE (TREE_TYPE (op00type))))
-	{
-	  tree size = TYPE_SIZE_UNIT (type);
-	  if (tree_int_cst_equal (size, op01))
-	    return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
-	}
+      /* *(p + CST) -> MEM_REF <p, CST>.  */
+      if (TREE_CODE (addr) != ADDR_EXPR
+	  || DECL_P (TREE_OPERAND (addr, 0)))
+	return fold_build2 (MEM_REF, type,
+			    addr,
+			    build_int_cst_wide (ptype,
+						TREE_INT_CST_LOW (off),
+						TREE_INT_CST_HIGH (off)));
     }
 
   /* *(foo *)fooarrptr => (*fooarrptr)[0] */
@@ -6558,7 +6565,8 @@ gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
            || gimple_test_f == is_gimple_mem_rhs_or_call
            || gimple_test_f == is_gimple_reg_rhs
            || gimple_test_f == is_gimple_reg_rhs_or_call
-           || gimple_test_f == is_gimple_asm_val)
+           || gimple_test_f == is_gimple_asm_val
+	   || gimple_test_f == is_gimple_mem_ref_addr)
     gcc_assert (fallback & fb_rvalue);
   else if (gimple_test_f == is_gimple_min_lval
 	   || gimple_test_f == is_gimple_lvalue)
@@ -6764,19 +6772,57 @@ gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
 	  recalculate_side_effects (*expr_p);
 	  break;
 
+	case ALIGN_INDIRECT_REF:
+	case MISALIGNED_INDIRECT_REF:
+	  /* We can only reach this through re-gimplification from
+	     tree optimizers.  */
+	  ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
+			       is_gimple_reg, fb_rvalue);
+	  recalculate_side_effects (*expr_p);
+	  break;
+
 	case INDIRECT_REF:
-	  *expr_p = fold_indirect_ref_loc (input_location, *expr_p);
-	  if (*expr_p != save_expr)
+	  {
+	    bool volatilep = TREE_THIS_VOLATILE (*expr_p);
+	    tree saved_ptr_type = TREE_TYPE (TREE_OPERAND (*expr_p, 0));
+
+	    *expr_p = fold_indirect_ref_loc (input_location, *expr_p);
+	    if (*expr_p != save_expr)
+	      {
+		ret = GS_OK;
+		break;
+	      }
+
+	    ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
+				 is_gimple_reg, fb_rvalue);
+	    recalculate_side_effects (*expr_p);
+
+	    *expr_p = fold_build2_loc (input_location, MEM_REF,
+				       TREE_TYPE (*expr_p),
+				       TREE_OPERAND (*expr_p, 0),
+				       build_int_cst (saved_ptr_type, 0));
+	    TREE_THIS_VOLATILE (*expr_p) = volatilep;
+	    ret = GS_OK;
+	    break;
+	  }
+
+	/* We arrive here through the various re-gimplifcation paths.  */
+	case MEM_REF:
+	  /* First try re-folding the whole thing.  */
+	  tmp = fold_binary (MEM_REF, TREE_TYPE (*expr_p),
+			     TREE_OPERAND (*expr_p, 0),
+			     TREE_OPERAND (*expr_p, 1));
+	  if (tmp)
 	    {
+	      *expr_p = tmp;
+	      recalculate_side_effects (*expr_p);
 	      ret = GS_OK;
 	      break;
 	    }
-	  /* else fall through.  */
-	case ALIGN_INDIRECT_REF:
-	case MISALIGNED_INDIRECT_REF:
 	  ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
-			       is_gimple_reg, fb_rvalue);
+			       is_gimple_mem_ref_addr, fb_rvalue);
 	  recalculate_side_effects (*expr_p);
+	  ret = GS_ALL_DONE;
 	  break;
 
 	  /* Constants need not be gimplified.  */