extend DECL_GIMPLE_REG_P to all types

This extends DECL_GIMPLE_REG_P to all types so we can clear
TREE_ADDRESSABLE even for integers with partial defs, not just
complex and vector variables.  To make that transition easier
the patch inverts DECL_GIMPLE_REG_P to DECL_NOT_GIMPLE_REG_P
since that makes the default the current state for all other
types besides complex and vectors.

For the testcase in PR94703 we're able to expand the partial
def'ed local integer to a register then, producing a single
movl rather than going through the stack.

On i?86 this execute FAILs gcc.dg/torture/pr71522.c because
we now expand a round-trip through a long double automatic var
to a register fld/fst which normalizes the value.  For that
during RTL expansion we're looking for problematic punnings
of decls and avoid pseudos for those - I chose integer or
BLKmode accesses on decls with modes where precision doesn't
match bitsize which covers the XFmode case.

2020-05-07  Richard Biener  <rguenther@suse.de>

	PR middle-end/94703
	* tree-core.h (tree_decl_common::gimple_reg_flag): Rename ...
	(tree_decl_common::not_gimple_reg_flag): ... to this.
	* tree.h (DECL_GIMPLE_REG_P): Rename ...
	(DECL_NOT_GIMPLE_REG_P): ... to this.
	* gimple-expr.c (copy_var_decl): Copy DECL_NOT_GIMPLE_REG_P.
	(create_tmp_reg): Simplify.
	(create_tmp_reg_fn): Likewise.
	(is_gimple_reg): Check DECL_NOT_GIMPLE_REG_P for all regs.
	* gimplify.c (create_tmp_from_val): Simplify.
	(gimplify_bind_expr): Likewise.
	(gimplify_compound_literal_expr): Likewise.
	(gimplify_function_tree): Likewise.
	(prepare_gimple_addressable): Set DECL_NOT_GIMPLE_REG_P.
	* asan.c (create_odr_indicator): Do not clear DECL_GIMPLE_REG_P.
	(asan_add_global): Copy it.
	* cgraphunit.c (cgraph_node::expand_thunk): Force args
	to be GIMPLE regs.
	* function.c (gimplify_parameters): Copy
	DECL_NOT_GIMPLE_REG_P.
	* ipa-param-manipulation.c
	(ipa_param_body_adjustments::common_initialization): Simplify.
	(ipa_param_body_adjustments::reset_debug_stmts): Copy
	DECL_NOT_GIMPLE_REG_P.
	* omp-low.c (lower_omp_for_scan): Do not set DECL_GIMPLE_REG_P.
	* sanopt.c (sanitize_rewrite_addressable_params): Likewise.
	* tree-cfg.c (make_blocks_1): Simplify.
	(verify_address): Do not verify DECL_GIMPLE_REG_P setting.
	* tree-eh.c (lower_eh_constructs_2): Simplify.
	* tree-inline.c (declare_return_variable): Adjust and
	generalize.
	(copy_decl_to_var): Copy DECL_NOT_GIMPLE_REG_P.
	(copy_result_decl_to_var): Likewise.
	* tree-into-ssa.c (pass_build_ssa::execute): Adjust comment.
	* tree-nested.c (create_tmp_var_for): Simplify.
	* tree-parloops.c (separate_decls_in_region_name): Copy
	DECL_NOT_GIMPLE_REG_P.
	* tree-sra.c (create_access_replacement): Adjust and
	generalize partial def support.
	* tree-ssa-forwprop.c (pass_forwprop::execute): Set
	DECL_NOT_GIMPLE_REG_P on decls we introduce partial defs on.
	* tree-ssa.c (maybe_optimize_var): Handle clearing of
	TREE_ADDRESSABLE and setting/clearing DECL_NOT_GIMPLE_REG_P
	independently.
	* lto-streamer-out.c (hash_tree): Hash DECL_NOT_GIMPLE_REG_P.
	* tree-streamer-out.c (pack_ts_decl_common_value_fields): Stream
	DECL_NOT_GIMPLE_REG_P.
	* tree-streamer-in.c (unpack_ts_decl_common_value_fields): Likewise.
	* cfgexpand.c (avoid_type_punning_on_regs): New.
	(discover_nonconstant_array_refs): Call
	avoid_type_punning_on_regs to avoid unsupported mode punning.

	lto/
	* lto-common.c (compare_tree_sccs_1): Compare
	DECL_NOT_GIMPLE_REG_P.

	c/
	* gimple-parser.c (c_parser_parse_ssa_name): Do not set
	DECL_GIMPLE_REG_P.

	cp/
	* optimize.c (update_cloned_parm): Copy DECL_NOT_GIMPLE_REG_P.

	* gcc.dg/tree-ssa/pr94703.c: New testcase.

1 files changed, 2 insertions, 44 deletions

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 7807e30fb2e..1d532e6f373 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -559,9 +559,6 @@ create_tmp_from_val (tree val)
   /* Drop all qualifiers and address-space information from the value type.  */
   tree type = TYPE_MAIN_VARIANT (TREE_TYPE (val));
   tree var = create_tmp_var (type, get_name (val));
-  if (TREE_CODE (TREE_TYPE (var)) == COMPLEX_TYPE
-      || TREE_CODE (TREE_TYPE (var)) == VECTOR_TYPE)
-    DECL_GIMPLE_REG_P (var) = 1;
   return var;
 }
 
@@ -1400,16 +1397,6 @@ gimplify_bind_expr (tree *expr_p, gimple_seq *pre_p)
 	  if (DECL_HARD_REGISTER (t) && !is_global_var (t) && cfun)
 	    cfun->has_local_explicit_reg_vars = true;
 	}
-
-      /* Preliminarily mark non-addressed complex variables as eligible
-	 for promotion to gimple registers.  We'll transform their uses
-	 as we find them.  */
-      if ((TREE_CODE (TREE_TYPE (t)) == COMPLEX_TYPE
-	   || TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
-	  && !TREE_THIS_VOLATILE (t)
-	  && (VAR_P (t) && !DECL_HARD_REGISTER (t))
-	  && !needs_to_live_in_memory (t))
-	DECL_GIMPLE_REG_P (t) = 1;
     }
 
   bind_stmt = gimple_build_bind (BIND_EXPR_VARS (bind_expr), NULL,
@@ -4308,7 +4295,7 @@ prepare_gimple_addressable (tree *expr_p, gimple_seq *seq_p)
     {
       /* Do not allow an SSA name as the temporary.  */
       tree var = get_initialized_tmp_var (*expr_p, seq_p, NULL, false);
-      DECL_GIMPLE_REG_P (var) = 0;
+      DECL_NOT_GIMPLE_REG_P (var) = 1;
       *expr_p = var;
     }
 }
@@ -4774,15 +4761,6 @@ gimplify_compound_literal_expr (tree *expr_p, gimple_seq *pre_p,
       return GS_OK;
     }
 
-  /* Preliminarily mark non-addressed complex variables as eligible
-     for promotion to gimple registers.  We'll transform their uses
-     as we find them.  */
-  if ((TREE_CODE (TREE_TYPE (decl)) == COMPLEX_TYPE
-       || TREE_CODE (TREE_TYPE (decl)) == VECTOR_TYPE)
-      && !TREE_THIS_VOLATILE (decl)
-      && !needs_to_live_in_memory (decl))
-    DECL_GIMPLE_REG_P (decl) = 1;
-
   /* If the decl is not addressable, then it is being used in some
      expression or on the right hand side of a statement, and it can
      be put into a readonly data section.  */
@@ -5617,8 +5595,7 @@ is_gimple_stmt (tree t)
 
 
 /* Promote partial stores to COMPLEX variables to total stores.  *EXPR_P is
-   a MODIFY_EXPR with a lhs of a REAL/IMAGPART_EXPR of a variable with
-   DECL_GIMPLE_REG_P set.
+   a MODIFY_EXPR with a lhs of a REAL/IMAGPART_EXPR of a gimple register.
 
    IMPORTANT NOTE: This promotion is performed by introducing a load of the
    other, unmodified part of the complex object just before the total store.
@@ -14992,7 +14969,6 @@ flag_instrument_functions_exclude_p (tree fndecl)
 void
 gimplify_function_tree (tree fndecl)
 {
-  tree parm, ret;
   gimple_seq seq;
   gbind *bind;
 
@@ -15007,24 +14983,6 @@ gimplify_function_tree (tree fndecl)
      if necessary.  */
   cfun->curr_properties |= PROP_gimple_lva;
 
-  for (parm = DECL_ARGUMENTS (fndecl); parm ; parm = DECL_CHAIN (parm))
-    {
-      /* Preliminarily mark non-addressed complex variables as eligible
-         for promotion to gimple registers.  We'll transform their uses
-         as we find them.  */
-      if ((TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
-	   || TREE_CODE (TREE_TYPE (parm)) == VECTOR_TYPE)
-          && !TREE_THIS_VOLATILE (parm)
-          && !needs_to_live_in_memory (parm))
-        DECL_GIMPLE_REG_P (parm) = 1;
-    }
-
-  ret = DECL_RESULT (fndecl);
-  if ((TREE_CODE (TREE_TYPE (ret)) == COMPLEX_TYPE
-       || TREE_CODE (TREE_TYPE (ret)) == VECTOR_TYPE)
-      && !needs_to_live_in_memory (ret))
-    DECL_GIMPLE_REG_P (ret) = 1;
-
   if (asan_sanitize_use_after_scope () && sanitize_flags_p (SANITIZE_ADDRESS))
     asan_poisoned_variables = new hash_set<tree> ();
   bind = gimplify_body (fndecl, true);