* doc/invoke.texi: Document -mlong-calls for 68HC12.

	* config/m68hc11/m68hc11.h (CPP_SPEC): Pass -D__USE_RTC__ when
	-mlong-calls is specified.
	(ASM_DECLARE_FUNCTION_NAME): Define to generate .far and .interrupt
	assembler directives.
	(TARGET_LONG_CALL, MASK_LONG_CALL): Declare.
	(TARGET_SWITCHES): Add -mlong-calls options.
	(current_function_far): Declare.

	* config/m68hc11/m68hc11.c (m68hc11_initial_elimination_offset): Take
	into account the page register saved on the stack.
	(m68hc11_override_options): Take into account -mlong-calls option.
	(m68hc11_asm_file_start): Put a mode for the ELF flags ABI.

	* config/m68hc11/m68hc11.md ("*return_32bit"): Return rtc
	if the function is going to be in 68HC12 banked memory (-mlong-calls).
	("*return_16bit"): Likewise.
	("*return_void"): Likewise.
	("call", "call_value"): Use call for a far function call.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@56275 138bc75d-0d04-0410-961f-82ee72b054a4

3 files changed, 74 insertions, 6 deletions

diff --git a/gcc/config/m68hc11/m68hc11.c b/gcc/config/m68hc11/m68hc11.c
index 1c85ca592a9..d52289fc314 100644
--- a/gcc/config/m68hc11/m68hc11.c
+++ b/gcc/config/m68hc11/m68hc11.c
@@ -101,6 +101,10 @@ int current_function_interrupt;
 /* Set to 1 by expand_prologue() when the function is a trap handler.  */
 int current_function_trap;
 
+/* Set to 1 when the current function is placed in 68HC12 banked
+   memory and must return with rtc.  */
+int current_function_far;
+
 /* Min offset that is valid for the indirect addressing mode.  */
 HOST_WIDE_INT m68hc11_min_offset = 0;
 
@@ -283,6 +287,9 @@ m68hc11_override_options ()
       target_flags |= MASK_NO_DIRECT_MODE;
       if (m68hc11_soft_reg_count == 0)
 	m68hc11_soft_reg_count = "0";
+
+      if (TARGET_LONG_CALLS)
+        current_function_far = 1;
     }
   return 0;
 }
@@ -1277,6 +1284,11 @@ m68hc11_initial_elimination_offset (from, to)
   trap_handler = lookup_attribute ("trap", func_attr) != NULL_TREE;
   if (trap_handler && from == ARG_POINTER_REGNUM)
     size = 7;
+
+  /* For a function using 'call/rtc' we must take into account the
+     page register which is pushed in the call.  */
+  else if (current_function_far && from == ARG_POINTER_REGNUM)
+    size = 1;
   else
     size = 0;
 
@@ -5500,6 +5512,11 @@ m68hc11_asm_file_start (out, main_file)
   print_options (out);
   fprintf (out, ";;;-----------------------------------------\n");
   output_file_directive (out, main_file);
+
+  if (TARGET_SHORT)
+    fprintf (out, "\t.mode mshort\n");
+  else
+    fprintf (out, "\t.mode mlong\n");
 }
 
 
diff --git a/gcc/config/m68hc11/m68hc11.h b/gcc/config/m68hc11/m68hc11.h
index 5a9fc529c64..32a9b6351ef 100644
--- a/gcc/config/m68hc11/m68hc11.h
+++ b/gcc/config/m68hc11/m68hc11.h
@@ -66,7 +66,8 @@ Note:
  %{!mshort:-D__INT__=32}\
  %{m68hc12:-Dmc6812 -DMC6812 -Dmc68hc12}\
  %{!m68hc12:-Dmc6811 -DMC6811 -Dmc68hc11}\
- %{fshort-double:-D__HAVE_SHORT_DOUBLE__}"
+ %{fshort-double:-D__HAVE_SHORT_DOUBLE__}\
+ %{mlong-calls:-D__USE_RTC__}"
 #endif
 
 #undef STARTFILE_SPEC
@@ -119,6 +120,7 @@ extern short *reg_renumber;	/* def in local_alloc.c */
 #define MASK_M6811              0010
 #define MASK_M6812              0020
 #define MASK_NO_DIRECT_MODE     0040
+#define MASK_LONG_CALLS         0200
 
 #define TARGET_OP_TIME		(optimize && optimize_size == 0)
 #define TARGET_SHORT            (target_flags & MASK_SHORT)
@@ -127,6 +129,7 @@ extern short *reg_renumber;	/* def in local_alloc.c */
 #define TARGET_AUTO_INC_DEC     (target_flags & MASK_AUTO_INC_DEC)
 #define TARGET_NO_DIRECT_MODE   (target_flags & MASK_NO_DIRECT_MODE)
 #define TARGET_RELAX            (TARGET_NO_DIRECT_MODE)
+#define TARGET_LONG_CALLS       (target_flags & MASK_LONG_CALLS)
 
 /* Default target_flags if no switches specified.  */
 #ifndef TARGET_DEFAULT
@@ -159,6 +162,10 @@ extern short *reg_renumber;	/* def in local_alloc.c */
     N_("Auto pre/post decrement increment allowed")},		\
   { "noauto-incdec", - MASK_AUTO_INC_DEC,			\
     N_("Auto pre/post decrement increment not allowed")},	\
+  { "long-calls", MASK_LONG_CALLS,				\
+    N_("Use call and rtc for function calls and returns")},	\
+  { "nolong-calls", - MASK_LONG_CALLS,				\
+    N_("Use jsr and rts for function calls and returns")},	\
   { "relax", MASK_NO_DIRECT_MODE,                               \
     N_("Do not use direct addressing mode for soft registers")},\
   { "68hc11", MASK_M6811,					\
@@ -1549,6 +1556,45 @@ do {                                                                    \
    no longer contain unusual constructs.  */
 #define ASM_APP_OFF 		"; End of inline assembler code\n#NO_APP\n"
 
+/* Write the extra assembler code needed to declare a function properly.
+   Some svr4 assemblers need to also have something extra said about the
+   function's return value.  We allow for that here.
+
+   For 68HC12 we mark functions that return with 'rtc'.  The linker
+   will ensure that a 'call' is really made (instead of 'jsr').
+   The debugger needs this information to correctly compute the stack frame.
+
+   For 68HC11/68HC12 we also mark interrupt handlers for gdb to
+   compute the correct stack frame.  */
+
+#undef ASM_DECLARE_FUNCTION_NAME
+#define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL)	\
+  do							\
+    {							\
+      fprintf (FILE, "%s", TYPE_ASM_OP);		\
+      assemble_name (FILE, NAME);			\
+      putc (',', FILE);					\
+      fprintf (FILE, TYPE_OPERAND_FMT, "function");	\
+      putc ('\n', FILE);				\
+      							\
+      if (TARGET_M6812 && current_function_far)		\
+        {						\
+          fprintf (FILE, "\t.far\t");			\
+	  assemble_name (FILE, NAME);			\
+	  putc ('\n', FILE);				\
+	}						\
+      else if (current_function_interrupt		\
+	       || current_function_trap)		\
+        {						\
+	  fprintf (FILE, "\t.interrupt\t");		\
+	  assemble_name (FILE, NAME);			\
+	  putc ('\b', FILE);				\
+	}						\
+      ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL));	\
+      ASM_OUTPUT_LABEL(FILE, NAME);			\
+    }							\
+  while (0)
+
 /* Output #ident as a .ident.  */
 
 /* output external reference */
@@ -1703,3 +1749,4 @@ extern int debug_m6811;
 extern int z_replacement_completed;
 extern int current_function_interrupt;
 extern int current_function_trap;
+extern int current_function_far;
diff --git a/gcc/config/m68hc11/m68hc11.md b/gcc/config/m68hc11/m68hc11.md
index da17dd6db4f..3c0f197e967 100644
--- a/gcc/config/m68hc11/m68hc11.md
+++ b/gcc/config/m68hc11/m68hc11.md
@@ -6279,12 +6279,14 @@
   ""
  "*
 {
+  int far_call = current_function_far;
+
   if (GET_CODE (XEXP (operands[0], 0)) == SYMBOL_REF)
     {
       if (SYMBOL_REF_FLAG (XEXP (operands[0], 0)) == 1)
         return \"swi\";
       else
-        return \"bsr\\t%0\";
+        return far_call ? \"call\\t%0\" : \"bsr\\t%0\";
     }
   else
     {
@@ -6299,12 +6301,14 @@
   ""
  "*
 {
+  int far_call = current_function_far;
+
   if (GET_CODE (XEXP (operands[1], 0)) == SYMBOL_REF)
     {
       if (SYMBOL_REF_FLAG (XEXP (operands[1], 0)) == 1)
         return \"swi\";
       else
-        return \"bsr\\t%1\";
+        return far_call ? \"call\\t%1\" : \"bsr\\t%1\";
     }
   else
     {
@@ -6418,7 +6422,7 @@
     return \"\";
   if (current_function_interrupt || current_function_trap)
     return \"rti\";
-  return \"rts\";
+  return current_function_far ? \"rtc\" : \"rts\";
 }")
 
 (define_insn "*return_16bit"
@@ -6435,7 +6439,7 @@
     return \"\";
   if (current_function_interrupt || current_function_trap)
     return \"rti\";
-  return \"rts\";
+  return current_function_far ? \"rtc\" : \"rts\";
 }")
 
 (define_insn "*return_32bit"
@@ -6452,7 +6456,7 @@
     return \"\";
   if (current_function_interrupt || current_function_trap)
     return \"rti\";
-  return \"rts\";
+  return current_function_far ? \"rtc\" : \"rts\";
 }")
 
 (define_insn "indirect_jump"