[gomp4, wip] remove references to ganglocal shared memory inside gcc

[Cesar Philippidis <cesar at codesourcery dot com>]

This patch strips out all of the references to ganglocal memory in gcc.
Unfortunately, the runtime api still takes a shared memory parameter, so
I haven't made any changes there yet. Perhaps we could still keep the
shared memory argument to GOACC_parallel, but remove all of the support
for ganglocal mappings. Then again, maybe we still need support
ganglocal mappings for legacy purposes.

With the ganglocal mapping aside, I'm in favor of leaving the shared
memory argument to GOACC_parallel, just in case we find another use for
shared memory in the future.

Nathan, what do you want to do here?

Cesar

2015-08-26  Cesar Philippidis  <cesar@codesourcery.com>

	gcc/
	* builtins.c (expand_oacc_ganglocal_ptr): Delete.
	(expand_builtin): Remove stale GOACC_GET_GANGLOCAL_PTR builtin.
	* config/nvptx/nvptx.md (ganglocal_ptr): Delete.
	* gimple.h (struct gimple_statement_omp_parallel_layout): Remove
	ganglocal_size member.
	(gimple_omp_target_ganglocal_size): Delete.
	(gimple_omp_target_set_ganglocal_size): Delete.
	* omp-builtins.def (BUILT_IN_GOACC_GET_GANGLOCAL_PTR): Delete.
	* omp-low.c (struct omp_context): Remove ganglocal_init, ganglocal_ptr,
	ganglocal_size, ganglocal_size_host, worker_var, worker_count and
	worker_sync_elt.
	(alloc_var_ganglocal): Delete.
	(install_var_ganglocal): Delete.
	(new_omp_context): Don't use ganglocal memory.
	(expand_omp_target): Likewise.
	(lower_omp_taskreg): Likewise.
	(lower_omp_target): Likewise.
	* tree-parloops.c (create_parallel_loop): Likewise.
	* tree-pretty-print.c (dump_omp_clause): Remove support for
	GOMP_MAP_FORCE_TO_GANGLOCAL

diff --git a/gcc/builtins.c b/gcc/builtins.c
index 7c3ead1..f465716 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -5913,25 +5913,6 @@ expand_builtin_acc_on_device (tree exp, rtx target)
   return target;
 }
 
-static rtx
-expand_oacc_ganglocal_ptr (rtx target ATTRIBUTE_UNUSED)
-{
-#ifdef HAVE_ganglocal_ptr
-  enum insn_code icode;
-  icode = CODE_FOR_ganglocal_ptr;
-  rtx tmp = target;
-  if (!REG_P (tmp) || GET_MODE (tmp) != Pmode)
-    tmp = gen_reg_rtx (Pmode);
-  rtx insn = GEN_FCN (icode) (tmp);
-  if (insn != NULL_RTX)
-    {
-      emit_insn (insn);
-      return tmp;
-    }
-#endif
-  return NULL_RTX;
-}
-
 /* Expand an expression EXP that calls a built-in function,
    with result going to TARGET if that's convenient
    (and in mode MODE if that's convenient).
@@ -7074,12 +7055,6 @@ expand_builtin (tree exp, rtx target, rtx subtarget, machine_mode mode,
 	return target;
       break;
 
-    case BUILT_IN_GOACC_GET_GANGLOCAL_PTR:
-      target = expand_oacc_ganglocal_ptr (target);
-      if (target)
-	return target;
-      break;
-
     default:	/* just do library call, if unknown builtin */
       break;
     }
diff --git a/gcc/config/nvptx/nvptx.md b/gcc/config/nvptx/nvptx.md
index 3d734a8..d0d6564 100644
--- a/gcc/config/nvptx/nvptx.md
+++ b/gcc/config/nvptx/nvptx.md
@@ -1485,23 +1485,6 @@
   ""
   "%.\\tst.shared%u1\\t%1,%0;")
 
-(define_insn "ganglocal_ptr<mode>"
-  [(set (match_operand:P 0 "nvptx_register_operand" "")
-	(unspec:P [(const_int 0)] UNSPEC_SHARED_DATA))]
-  ""
-  "%.\\tcvta.shared%t0\\t%0, sdata;")
-
-(define_expand "ganglocal_ptr"
-  [(match_operand 0 "nvptx_register_operand" "")]
-  ""
-{
-  if (Pmode == DImode)
-    emit_insn (gen_ganglocal_ptrdi (operands[0]));
-  else
-    emit_insn (gen_ganglocal_ptrsi (operands[0]));
-  DONE;
-})
-
 ;; Atomic insns.
 
 (define_expand "atomic_compare_and_swap<mode>"
diff --git a/gcc/gimple.h b/gcc/gimple.h
index d8d8742..278b49f 100644
--- a/gcc/gimple.h
+++ b/gcc/gimple.h
@@ -580,10 +580,6 @@ struct GTY((tag("GSS_OMP_PARALLEL_LAYOUT")))
   /* [ WORD 10 ]
      Shared data argument.  */
   tree data_arg;
-
-  /* [ WORD 11 ]
-     Size of the gang-local memory to allocate.  */
-  tree ganglocal_size;
 };
 
 /* GIMPLE_OMP_PARALLEL or GIMPLE_TASK */
@@ -5232,25 +5228,6 @@ gimple_omp_target_set_data_arg (gomp_target *omp_target_stmt,
 }
 
 
-/* Return the size of gang-local data associated with OMP_TARGET GS.  */
-
-static inline tree
-gimple_omp_target_ganglocal_size (const gomp_target *omp_target_stmt)
-{
-  return omp_target_stmt->ganglocal_size;
-}
-
-
-/* Set SIZE to be the size of gang-local memory associated with OMP_TARGET
-   GS.  */
-
-static inline void
-gimple_omp_target_set_ganglocal_size (gomp_target *omp_target_stmt, tree size)
-{
-  omp_target_stmt->ganglocal_size = size;
-}
-
-
 /* Return the clauses associated with OMP_TEAMS GS.  */
 
 static inline tree
diff --git a/gcc/omp-builtins.def b/gcc/omp-builtins.def
index 0d9f386..615c4e0 100644
--- a/gcc/omp-builtins.def
+++ b/gcc/omp-builtins.def
@@ -58,8 +58,6 @@ DEF_GOACC_BUILTIN_FNSPEC (BUILT_IN_GOACC_UPDATE, "GOACC_update",
 DEF_GOACC_BUILTIN (BUILT_IN_GOACC_WAIT, "GOACC_wait",
 		   BT_FN_VOID_INT_INT_VAR,
 		   ATTR_NOTHROW_LIST)
-DEF_GOACC_BUILTIN (BUILT_IN_GOACC_GET_GANGLOCAL_PTR, "GOACC_get_ganglocal_ptr",
-		   BT_FN_PTR, ATTR_NOTHROW_LEAF_LIST)
 DEF_GOACC_BUILTIN (BUILT_IN_GOACC_DEVICEPTR, "GOACC_deviceptr",
 		   BT_FN_PTR_PTR, ATTR_CONST_NOTHROW_LEAF_LIST)
 DEF_GOACC_BUILTIN_COMPILER (BUILT_IN_ACC_ON_DEVICE, "acc_on_device",
diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index ee92141..19d66fa 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -212,21 +212,6 @@ typedef struct omp_context
      this level and above.  For parallel and kernels clauses, a mask
      indicating which of num_gangs/num_workers/num_vectors was used.  */
   int gwv_this;
-
-  gimple_seq ganglocal_init;
-  tree ganglocal_ptr;
-  tree ganglocal_size;
-  tree ganglocal_size_host;
-
-  /* For OpenACC offloaded regions, variables holding the worker id and count
-     of workers.  */
-  tree worker_var;
-  tree worker_count;
-
-  /* For offloaded regions, at runtime this variable holds a pointer
-     to the location that should be used for thread
-     synchronization.  */
-  tree worker_sync_elt;
 } omp_context;
 
 /* A structure holding the elements of:
@@ -1448,96 +1433,6 @@ align_and_expand (tree *poldsz, tree size, unsigned int align)
   return fold_build2 (PLUS_EXPR, size_type_node, oldsz, size);
 }
 
-/* Generate code at the entry to CTX to allocate SIZE bytes of gang-local
-   memory, cast this to be a pointer to VARTYPE and return the result.
-   UNDERLYING_VAR is used to choose a name, it can be NULL.
-
-   FIXME: Consider pointer to arrays.  */
-
-static tree
-alloc_var_ganglocal (tree underlying_var, tree vartype, omp_context *ctx,
-		     tree size, tree host_size = NULL)
-{
-  /* If this is a pointer mapping, then we need to create too mappings, one
-     for the pointer, and another to the data.  Add the offset for the pointer
-     to size.  */
-  bool pointer = underlying_var ? is_reference (underlying_var) : false;
-
-  if (pointer)
-    size = fold_build2 (PLUS_EXPR, TREE_TYPE (size), size,
-			TYPE_SIZE_UNIT (ptr_type_node));
-
-  if (host_size == NULL)
-    host_size = size;
-  else if (pointer)
-    {
-      host_size = fold_build2 (PLUS_EXPR, TREE_TYPE (size), host_size,
-			       TYPE_SIZE_UNIT (ptr_type_node));
-    }
-
-  if (ctx->ganglocal_ptr == NULL_TREE)
-    {
-      tree ptr = create_tmp_var (ptr_type_node, "__ganglocal_ptr");
-      tree fndecl = builtin_decl_explicit (BUILT_IN_GOACC_GET_GANGLOCAL_PTR);
-      gimple g = gimple_build_call (fndecl, 0);
-      gimple_call_set_lhs (g, ptr);
-      gimple_seq_add_stmt (&ctx->ganglocal_init, g);
-
-      ctx->ganglocal_ptr = ptr;
-    }
-  const char *name = NULL;
-  if (underlying_var && DECL_NAME (underlying_var))
-    name = IDENTIFIER_POINTER (DECL_NAME (underlying_var));
-  tree oldsz = ctx->ganglocal_size;
-  tree varptrtype = build_pointer_type (vartype);
-
-  unsigned int align = TYPE_ALIGN_UNIT (vartype);
-  tree newsz = align_and_expand (&oldsz, size, align);
-  tree gl_host = ctx->ganglocal_size_host;
-  ctx->ganglocal_size_host = align_and_expand (&gl_host, host_size, align);
-  ctx->ganglocal_size = newsz;
-
-  tree newvarptr = create_tmp_var (varptrtype, name);
-#if 0
-  DECL_CHAIN (newvarptr) = ctx->block_vars;
-  ctx->block_vars = newvarptr;
-#endif
-  tree device_off = oldsz;
-  walk_tree (&device_off, copy_tree_body_r, &ctx->cb, NULL);
-
-  tree x = fold_convert (varptrtype,
-			 fold_build_pointer_plus (ctx->ganglocal_ptr,
-						  device_off));
-  gimple g = gimple_build_assign (newvarptr, x);
-  gimple_seq_add_stmt (&ctx->ganglocal_init, g);
-
-  /* Add a target for the pointer.  */
-  if (pointer)
-    {
-      tree vtype = build_pointer_type (size_type_node);
-      tree t = create_tmp_var (vtype);
-      x = fold_convert (vtype, x);
-      g = gimple_build_assign (t, x);
-      gimple_seq_add_stmt (&ctx->ganglocal_init, g);
-
-      x = fold_build_pointer_plus (x, build_int_cst (sizetype, 8));
-      g = gimple_build_assign (build_simple_mem_ref (t),
-			       fold_convert (sizetype, x));
-      gimple_seq_add_stmt (&ctx->ganglocal_init, g);
-    }
-  return newvarptr;
-}
-
-static tree
-install_var_ganglocal (tree decl, omp_context *ctx)
-{
-  tree type = TREE_TYPE (decl);
-  tree ptr = alloc_var_ganglocal (decl, type, ctx, TYPE_SIZE_UNIT (type));
-  tree new_var = build1 (INDIRECT_REF, type, ptr);
-  insert_decl_map (&ctx->cb, decl, new_var);
-  return new_var;
-}
-
 /* Debugging dumps for parallel regions.  */
 void dump_omp_region (FILE *, struct omp_region *, int);
 void debug_omp_region (struct omp_region *);
@@ -1675,8 +1570,6 @@ new_omp_context (gimple stmt, omp_context *outer_ctx)
       ctx->cb.transform_call_graph_edges = CB_CGE_MOVE;
       ctx->depth = 1;
     }
-  ctx->ganglocal_size = size_zero_node;
-  ctx->ganglocal_size_host = size_zero_node;
   ctx->cb.decl_map = new hash_map<tree, tree>;
 
   return ctx;
@@ -10056,8 +9949,9 @@ expand_omp_target (struct omp_region *region)
     case BUILT_IN_GOACC_KERNELS_INTERNAL:
     case BUILT_IN_GOACC_PARALLEL:
       {
-	args.quick_push (gimple_omp_target_ganglocal_size (entry_stmt));
-	set_oacc_fn_attrib (child_fn, clauses, &args);
+	tree shared_memory = build_int_cst (integer_type_node, 0);
+	args.quick_push (shared_memory);
+	set_oacc_fn_attrib (clauses, child_fn, &args);
 	tagging = true;
       }
       /* FALLTHRU */
@@ -11935,39 +11829,6 @@ lower_omp_taskreg (gimple_stmt_iterator *gsi_p, omp_context *ctx)
     }
 }
 
-/* A subroutine of lower_omp_target.  Build variables holding the
-   worker count and index for use inside in ganglocal memory allocations.  */
-
-static void
-oacc_init_count_vars (omp_context *ctx, tree clauses ATTRIBUTE_UNUSED)
-{
-  tree worker_var, worker_count;
-  
-  if (ctx->gwv_this & GOMP_DIM_MASK (GOMP_DIM_WORKER))
-    {
-      tree arg = build_int_cst (unsigned_type_node, GOMP_DIM_WORKER);
-      
-      worker_var = create_tmp_var (integer_type_node, ".worker");
-      worker_count = create_tmp_var (integer_type_node, ".workercount");
-      
-      gimple call1 = gimple_build_call_internal (IFN_GOACC_DIM_POS, 1, arg);
-      gimple_call_set_lhs (call1, worker_var);
-      gimple_seq_add_stmt (&ctx->ganglocal_init, call1);
-
-      gimple call2 = gimple_build_call_internal (IFN_GOACC_DIM_SIZE, 1, arg);
-      gimple_call_set_lhs (call2, worker_count);
-      gimple_seq_add_stmt (&ctx->ganglocal_init, call2);
-    }
-  else
-    {
-      worker_var = build_int_cst (integer_type_node, 0);
-      worker_count = build_int_cst (integer_type_node, 1);
-    }
-  
-  ctx->worker_var = worker_var;
-  ctx->worker_count = worker_count;
-}
-
 /* Lower the GIMPLE_OMP_TARGET in the current statement
    in GSI_P.  CTX holds context information for the directive.  */
 
@@ -12057,7 +11918,6 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
 	    break;
 	  case GOMP_MAP_FORCE_ALLOC:
 	  case GOMP_MAP_FORCE_TO:
-	  case GOMP_MAP_FORCE_TO_GANGLOCAL:
 	  case GOMP_MAP_FORCE_FROM:
 	  case GOMP_MAP_FORCE_TOFROM:
 	  case GOMP_MAP_FORCE_PRESENT:
@@ -12127,15 +11987,7 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
 		DECL_HAS_VALUE_EXPR_P (new_var) = 1;
 	      }
 	    else
-	      {
-		/* Copy from the receiver field to gang-local memory.  */
-		gcc_assert (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
-			    && (OMP_CLAUSE_MAP_KIND (c)
-				== GOMP_MAP_FORCE_TO_GANGLOCAL)
-			    && TREE_CODE (new_var) == INDIRECT_REF);
-		gimple g = gimple_build_assign (new_var, x);
-		gimple_seq_add_stmt (&ctx->ganglocal_init, g);
-	      }
+	      gcc_unreachable ();
 	  }
 	map_cnt++;
 	break;
@@ -12153,9 +12005,6 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
   irlist = NULL;
   orlist = NULL;
 
-  if (is_gimple_omp_oacc (stmt))
-    oacc_init_count_vars (ctx, clauses);
-
   if (is_oacc_parallel (ctx) && ctx->reductions)
     {
       lower_oacc_reductions (IFN_GOACC_REDUCTION_SETUP, GOMP_DIM_GANG,
@@ -12168,8 +12017,6 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
 			      clauses, &orlist, ctx, true);
     }
 
-  lower_omp (&ctx->ganglocal_init, ctx);
-
   if (offloaded)
     {
       /* Declare all the variables created by mapping and the variables
@@ -12424,7 +12271,6 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
       gimple_seq_add_stmt (&new_body,
 	  		   gimple_build_assign (ctx->receiver_decl, t));
     }
-  gimple_seq_add_seq (&new_body, ctx->ganglocal_init);
   gimple_seq_add_seq (&new_body, fplist);
 
   if (offloaded)
@@ -12457,14 +12303,6 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
   gimple_bind_add_stmt (bind, stmt);
   gimple_bind_add_seq (bind, olist);
 
-  gimple_seq sz_ilist = NULL;
-  tree sz = create_tmp_var (size_type_node, "__ganglocal_size");
-  gimplify_and_add (build2 (MODIFY_EXPR, size_type_node, sz,
-			    ctx->ganglocal_size_host),
-		    &sz_ilist);
-  gsi_insert_seq_before (gsi_p, sz_ilist, GSI_SAME_STMT);
-
-  gimple_omp_target_set_ganglocal_size (stmt, sz);
   pop_gimplify_context (NULL);
 }
 
diff --git a/gcc/tree-parloops.c b/gcc/tree-parloops.c
index c124b87..c6942d5 100644
--- a/gcc/tree-parloops.c
+++ b/gcc/tree-parloops.c
@@ -2080,9 +2080,6 @@ create_parallel_loop (struct loop *loop, tree loop_fn, tree data,
       gimple_omp_target_set_child_fn (stmt, child_fn);
       tree data_arg = gimple_omp_target_data_arg (kernels);
       gimple_omp_target_set_data_arg (stmt, data_arg);
-      tree ganglocal_size
-	= gimple_call_arg (goacc_kernels_internal, /* TODO */ 6);
-      gimple_omp_target_set_ganglocal_size (stmt, ganglocal_size);
 
       gimple_set_location (stmt, loc);
 
diff --git a/gcc/tree-pretty-print.c b/gcc/tree-pretty-print.c
index 8da3dcd..1b52aa2 100644
--- a/gcc/tree-pretty-print.c
+++ b/gcc/tree-pretty-print.c
@@ -537,9 +537,6 @@ dump_omp_clause (pretty_printer *pp, tree clause, int spc, int flags)
 	case GOMP_MAP_FORCE_TO:
 	  pp_string (pp, "force_to");
 	  break;
-	case GOMP_MAP_FORCE_TO_GANGLOCAL:
-	  pp_string (pp, "force_to_ganglocal");
-	  break;
 	case GOMP_MAP_FORCE_FROM:
 	  pp_string (pp, "force_from");
 	  break;
@@ -570,21 +567,12 @@ dump_omp_clause (pretty_printer *pp, tree clause, int spc, int flags)
 	  else if (OMP_CLAUSE_CODE (clause) == OMP_CLAUSE_MAP
 		   && OMP_CLAUSE_MAP_KIND (clause) == GOMP_MAP_TO_PSET)
 	    pp_string (pp, " [pointer set, len: ");
-
-	  else if (OMP_CLAUSE_CODE (clause) == OMP_CLAUSE_MAP
-		   && (OMP_CLAUSE_MAP_KIND (clause)
-		       == GOMP_MAP_FORCE_TO_GANGLOCAL))
-	    pp_string (pp, " [gang-local copy, len: ");
 	  else
 	    pp_string (pp, " [len: ");
 	  dump_generic_node (pp, OMP_CLAUSE_SIZE (clause),
 			     spc, flags, false);
 	  pp_right_bracket (pp);
 	}
-      else if (OMP_CLAUSE_CODE (clause) == OMP_CLAUSE_MAP
-	       && (OMP_CLAUSE_MAP_KIND (clause)
-		   == GOMP_MAP_FORCE_TO_GANGLOCAL))
-	pp_string (pp, " [gang-local copy]");
       pp_right_paren (pp);
       break;