Mostly reverted r27894, removed usage of unreachable.

The gain from using an extra Unreachable is rather low, plus the noreturn call must probably be keeped anyway, so revrt it again

[r27898]

include/libfirm/ircons.h

@@ -254,7 +254,6 @@
  *    ir_node *new_IJmp     (ir_node *tgt);
  *    ir_node *new_Cond     (ir_node *c);
  *    ir_node *new_Return   (ir_node *store, int arity, ir_node **in);
- *    ir_node *new_Unreachable (ir_node *store);
  *    ir_node *new_Const    (tarval *con);
  *    ir_node *new_SymConst (ir_mode *mode, symconst_symbol value, symconst_kind kind);
  *    ir_node *new_simpleSel (ir_node *store, ir_node *objptr, ir_entity *ent);
@@ -417,7 +416,7 @@
  *    -----------------------
  *
  *    In each block there must be exactly one of the control flow
- *    operations Start, End, Jmp, Cond, Return, Raise, or Unreachable.  The output of a
+ *    operations Start, End, Jmp, Cond, Return or Raise.  The output of a
  *    control flow operation points to the block to be executed next.
  *
  *    ir_node *new_Start (void)
@@ -502,16 +501,6 @@
  *    Output
  *      Control flow to the end block.
  *
- *    ir_node *new_Unreachable (ir_node *store)
- *    -----------------------------------------
- *
- *    The Unreachable node represents an unreachable control flow, typically
- *    after a noreturn call.  It passes the control flow to the end_block.
- *
- *    Inputs:
- *      The memory state.
- *    Output
- *      Control flow to the end block.
  *
  *    ir_node *new_Const (tarval *con)
  *    -----------------------------------------------
@@ -1226,16 +1215,6 @@ FIRM_API ir_node *new_rd_Cond(dbg_info *db, ir_node *block, ir_node *c);
 FIRM_API ir_node *new_rd_Return(dbg_info *db, ir_node *block,
                                 ir_node *store, int arity, ir_node *in[]);
 
-/** Constructor for an Unreachable node.
- *
- * Holds the memory.  Only node that can end unreachable control flow.
- *
- * @param *db    A pointer for debug information.
- * @param *block The IR block the node belongs to.
- * @param *store The state of memory.
- */
-FIRM_API ir_node *new_rd_Unreachable(dbg_info *db, ir_node *block, ir_node *store);
-
 /** Constructor for a Const_type node.
  *
  * Adds the node to the start block.
@@ -2071,15 +2050,6 @@ FIRM_API ir_node *new_r_Cond(ir_node *block, ir_node *c);
 FIRM_API ir_node *new_r_Return(ir_node *block, ir_node *store,
                                int arity, ir_node *in[]);
 
-/** Constructor for an Unreachable node.
- *
- * Holds the memory.  Only node that can end unreachable control flow.
- *
- * @param *block The IR block the node belongs to.
- * @param *store The state of memory.
- */
-FIRM_API ir_node *new_r_Unreachable(ir_node *block, ir_node *store);
-
 /** Constructor for a Const node.
  *
  * Adds the node to the start block.
@@ -2821,17 +2791,6 @@ FIRM_API ir_node *new_d_Cond(dbg_info *db, ir_node *c);
 FIRM_API ir_node *new_d_Return(dbg_info *db, ir_node *store,
                                int arity, ir_node *in[]);
 
-/** Constructor for an Unreachable node.
- *
- * Adds the node to the block in current_ir_block.
- *
- * Holds the memory.  Only node that can end unreachable control flow.
- *
- * @param *db    A pointer for debug information.
- * @param *store The state of memory.
- */
-FIRM_API ir_node *new_d_Unreachable(dbg_info *db, ir_node *store);
-
 /** Constructor for a Const_type node.
  *
  * Adds the node to the start block.
@@ -3596,15 +3555,6 @@ FIRM_API ir_node *new_Cond(ir_node *c);
  */
 FIRM_API ir_node *new_Return(ir_node *store, int arity, ir_node *in[]);
 
-/** Constructor for an Unreachable node.
- *
- * Holds the memory.  Only node that can end unreachable control flow.
- * Adds the node to the block in current_ir_block.
- *
- * @param *store The state of memory.
- */
-FIRM_API ir_node *new_Unreachable(ir_node *store);
-
 /** Constructor for a Const node.
  *
  * Constructor for a Const node. The constant represents a target

include/libfirm/nodeops.h

@@ -310,8 +310,6 @@ FIRM_API int is_Sync(const ir_node *node);
 FIRM_API int is_Tuple(const ir_node *node);
 /** Return true of the node is a Unknown node. */
 FIRM_API int is_Unknown(const ir_node *node);
-/** Return true of the node is a Unreachable node. */
-FIRM_API int is_Unreachable(const ir_node *node);
 
 
 FIRM_API ir_asm_constraint* get_ASM_input_constraints(const ir_node *node);
@@ -588,9 +586,6 @@ void set_Sub_right(ir_node *node, ir_node *right);
 
 
 
-
-FIRM_API ir_node *get_Unreachable_mem(const ir_node *node);
-void set_Unreachable_mem(ir_node *node, ir_node *mem);
 /** @} */
 
 #endif

include/libfirm/opcodes.h

@@ -62,9 +62,8 @@ typedef enum ir_opcode {
 	iro_Sync,
 	iro_Tuple,
 	iro_Unknown,
-	iro_Unreachable,
 	iro_First = iro_ASM,
-	iro_Last = iro_Unreachable,
+	iro_Last = iro_Unknown,
 
 	beo_First,
 	/* backend specific nodes */
@@ -146,7 +145,6 @@ FIRM_API ir_op *op_SymConst;
 FIRM_API ir_op *op_Sync;
 FIRM_API ir_op *op_Tuple;
 FIRM_API ir_op *op_Unknown;
-FIRM_API ir_op *op_Unreachable;
 
 
 FIRM_API ir_op *get_op_ASM(void);
@@ -206,6 +204,5 @@ FIRM_API ir_op *get_op_SymConst(void);
 FIRM_API ir_op *get_op_Sync(void);
 FIRM_API ir_op *get_op_Tuple(void);
 FIRM_API ir_op *get_op_Unknown(void);
-FIRM_API ir_op *get_op_Unreachable(void);
 
 #endif

ir/be/begnuas.c

@@ -894,7 +894,7 @@ static void emit_string_cst(const ir_entity *ent)
 	remaining_space = type_size - len;
 	assert(remaining_space >= 0);
 	if (remaining_space > 0) {
-		be_emit_irprintf("\t.space\t%d\n", remaining_space);
+		be_emit_irprintf("\t.space\t%d, 0\n", remaining_space);
 	}
 }
 
@@ -1214,7 +1214,7 @@ static void emit_initializer(be_gas_decl_env_t *env, const ir_entity *entity)
 
 		/* a gap */
 		if (space > 0) {
-			be_emit_irprintf("\t.space\t%d\n", space);
+			be_emit_irprintf("\t.space\t%d, 0\n", space);
 			be_emit_write_line();
 		}
 	}
@@ -1325,7 +1325,7 @@ static void emit_compound_graph_init(be_gas_decl_env_t *env,
 
 		/* a gap */
 		if (space > 0) {
-			be_emit_irprintf("\t.space\t%d\n", space);
+			be_emit_irprintf("\t.space\t%d, 0\n", space);
 			be_emit_write_line();
 		}
 	}
@@ -1561,7 +1561,7 @@ static void emit_global(be_gas_decl_env_t *env, const ir_entity *entity)
 	}
 
 	if (entity_is_null(entity)) {
-		be_emit_irprintf("\t.space %u\n", get_type_size_bytes(type));
+		be_emit_irprintf("\t.space %u, 0\n", get_type_size_bytes(type));
 		be_emit_write_line();
 	} else if (entity_has_compound_ent_values(entity)) {
 		emit_compound_graph_init(env, entity);

ir/be/besched.h

 /*
- * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
+ * Copyright (C) 1995-2010 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *

ir/be/betranshlp.c

@@ -121,7 +121,6 @@ void be_start_transform_setup(void)
 	be_set_transform_function(op_Pin,         be_duplicate_node);
 	be_set_transform_function(op_Start,       be_duplicate_node);
 	be_set_transform_function(op_Sync,        be_duplicate_node);
-	be_set_transform_function(op_Unreachable, be_duplicate_node);
 }
 
 ir_node *be_duplicate_node(ir_node *node)

ir/be/beverify.c

@@ -304,7 +304,6 @@ static int should_be_scheduled(ir_node *node)
 	case iro_Start:
 	case iro_Jmp:
 	case beo_Return:
-	case iro_Unreachable:
 		return 1;
 	default:
 		break;

ir/ir/irdump.c

@@ -760,7 +760,6 @@ static void dump_node_mode(FILE *F, ir_node *n)
 	case iro_Sel:
 	case iro_End:
 	case iro_Return:
-	case iro_Unreachable:
 	case iro_Free:
 	case iro_Sync:
 	case iro_Jmp:

ir/ir/irverify.c

@@ -893,10 +893,9 @@ static int verify_node_Block(ir_node *n, ir_graph *irg)
 				break;   /*  We can not test properly.  How many tuples are there? */
 			ASSERT_AND_RET(
 				(
-					is_Return(pred)      ||
-					is_Unreachable(pred) ||
-					is_Bad(pred)         ||
-					is_Raise(pred)       ||
+					is_Return(pred) ||
+					is_Bad(pred)    ||
+					is_Raise(pred)  ||
 					is_fragile_op(pred)
 				),
 				"End Block node", 0);

ir/opt/ldstopt.c

@@ -2185,8 +2185,6 @@ static void do_dfs(ir_graph *irg, loop_env *env)
 		pred = skip_Proj(pred);
 		if (is_Return(pred))
 			dfs(get_Return_mem(pred), env);
-		else if (is_Unreachable(pred))
-			dfs(get_Unreachable_mem(pred), env);
 		else if (is_Raise(pred))
 			dfs(get_Raise_mem(pred), env);
 		else if (is_fragile_op(pred))

scripts/ir_spec.py

@@ -633,12 +633,6 @@ class Return(Op):
 	flags    = [ "cfopcode" ]
 	pinned   = "yes"
 
-class Unreachable(Op):
-	ins      = [ "mem" ]
-	mode     = "mode_X"
-	flags    = [ "cfopcode" ]
-	pinned   = "yes"
-
 class Rotl(Binop):
 	flags    = []