amd64: Explicitly create function prologue/epilogue

ir/be/amd64/amd64_emitter.c

@@ -684,27 +684,8 @@ static void emit_be_IncSP(const ir_node *node)
 	}
 }
 
-static void emit_amd64_Start(const ir_node *node)
-{
-	ir_graph *irg        = get_irn_irg(node);
-	ir_type  *frame_type = get_irg_frame_type(irg);
-	unsigned  size       = get_type_size_bytes(frame_type);
-
-	if (size > 0) {
-		amd64_emitf(node, "subq $%u, %%rsp", size);
-	}
-}
-
 static void emit_amd64_Return(const ir_node *node)
 {
-	ir_graph *irg        = get_irn_irg(node);
-	ir_type  *frame_type = get_irg_frame_type(irg);
-	unsigned  size       = get_type_size_bytes(frame_type);
-
-	if (size > 0) {
-		amd64_emitf(node, "addq $%u, %%rsp", size);
-	}
-
 	be_emit_cstring("\tret");
 	be_emit_finish_line_gas(node);
 }
@@ -725,7 +706,7 @@ static void amd64_register_emitters(void)
 	be_set_emitter(op_amd64_Jmp,       emit_amd64_Jmp);
 	be_set_emitter(op_amd64_Mov,       emit_amd64_Mov);
 	be_set_emitter(op_amd64_Return,    emit_amd64_Return);
-	be_set_emitter(op_amd64_Start,     emit_amd64_Start);
+	be_set_emitter(op_amd64_Start,     be_emit_nothing);
 	be_set_emitter(op_amd64_SwitchJmp, emit_amd64_SwitchJmp);
 	be_set_emitter(op_be_Copy,         emit_be_Copy);
 	be_set_emitter(op_be_CopyKeep,     emit_be_Copy);

ir/be/amd64/bearch_amd64.c

@@ -326,6 +326,58 @@ static void amd64_collect_frame_entity_nodes(ir_node *node, void *data)
 	}
 }
 
+static void introduce_epilogue(ir_node *ret)
+{
+	const arch_register_t *sp         = &amd64_registers[REG_RSP];
+	ir_graph              *irg        = get_irn_irg(ret);
+	ir_node               *start      = get_irg_start(irg);
+	ir_node               *block      = get_nodes_block(start);
+	ir_type               *frame_type = get_irg_frame_type(irg);
+	unsigned               frame_size = get_type_size_bytes(frame_type);
+	be_stack_layout_t     *layout     = be_get_irg_stack_layout(irg);
+	ir_node               *first_sp   = get_irn_n(ret, n_be_Return_sp);
+	ir_node               *curr_sp    = first_sp;
+
+	if(!layout->sp_relative) {
+		assert(false);
+	} else {
+		if (frame_size > 0) {
+			ir_node *incsp = be_new_IncSP(sp, block, curr_sp,
+			                              - (int) frame_size, 0);
+			sched_add_before(ret, incsp);
+			curr_sp = incsp;
+		}
+	}
+	set_irn_n(ret, n_be_Return_sp, curr_sp);
+}
+
+static void introduce_prologue_epilogue(ir_graph *irg)
+{
+	const arch_register_t *sp         = &amd64_registers[REG_RSP];
+	ir_node               *start      = get_irg_start(irg);
+	ir_node               *block      = get_nodes_block(start);
+	ir_type               *frame_type = get_irg_frame_type(irg);
+	unsigned               frame_size = get_type_size_bytes(frame_type);
+	be_stack_layout_t     *layout     = be_get_irg_stack_layout(irg);
+	ir_node               *initial_sp = be_get_initial_reg_value(irg, sp);
+
+	if (!layout->sp_relative) {
+		assert(false);
+	} else {
+		if (frame_size > 0) {
+			ir_node *const incsp = be_new_IncSP(sp, block, initial_sp,
+			                                    frame_size, 0);
+			sched_add_after(start, incsp);
+		}
+	}
+
+	/* introduce epilogue for every return node */
+	foreach_irn_in(get_irg_end_block(irg), i, ret) {
+		assert(be_is_Return(ret) || is_amd64_Return(ret));
+		introduce_epilogue(ret);
+	}
+}
+
 /**
  * Called immediatly before emit phase.
  */
@@ -346,6 +398,8 @@ static void amd64_finish_graph(ir_graph *irg)
 	be_abi_fix_stack_nodes(irg);
 	be_abi_fix_stack_bias(irg);
 
+	introduce_prologue_epilogue(irg);
+
 	/* Fix 2-address code constraints. */
 	amd64_finish_irg(irg);