rs6000.h (INIT_EXPANDERS): Delete.

        2001-01-22  Franz Sirl  <Franz.Sirl-kernel@lauterbach.com>

        * rs6000.h (INIT_EXPANDERS): Delete.
        (RETURN_ADDR_RTX): Call rs6000_return_addr().
        * rs6000.c (rs6000_override_options): Call *_machine_status from
        here...
        (rs6000_init_expanders): ...instead of here. Delete.
        (rs6000_mark_machine_status): New function.
        (rs6000_init_machine_status): Use xcalloc.
        (rs6000_return_addr): Generate RTX for the return address.
        (rs6000_ra_ever_killed): New, check if LR was ever destroyed.
        (rs6000_stack_info): Use it.

From-SVN: r39188

3 files changed, 103 insertions, 32 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5e2f57d..26d488d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,16 @@
+2001-01-22  Franz Sirl  <Franz.Sirl-kernel@lauterbach.com>
+
+	* rs6000.h (INIT_EXPANDERS): Delete.
+	(RETURN_ADDR_RTX): Call rs6000_return_addr().
+	* rs6000.c (rs6000_override_options): Call *_machine_status from
+	here...
+	(rs6000_init_expanders): ...instead of here. Delete.
+	(rs6000_mark_machine_status): New function.
+	(rs6000_init_machine_status): Use xcalloc.
+	(rs6000_return_addr): Generate RTX for the return address.
+	(rs6000_ra_ever_killed): New, check if LR was ever destroyed.
+	(rs6000_stack_info): Use it.
+
 2001-01-22  Thomas Pfaff  <tpfaff@gmx.net>
 
 	* gthr-win32.h: Include errno.h to get a declaration for
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 318adb2..3fa0e0a 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -122,6 +122,8 @@ static void toc_hash_mark_table PARAMS ((void *));
 static int constant_pool_expr_1 PARAMS ((rtx, int *, int *));
 static void rs6000_free_machine_status PARAMS ((struct function *));
 static void rs6000_init_machine_status PARAMS ((struct function *));
+static void rs6000_mark_machine_status PARAMS ((struct function *));
+static int rs6000_ra_ever_killed PARAMS ((void));
 
 /* Default register names.  */
 char rs6000_reg_names[][8] =
@@ -399,6 +401,11 @@ rs6000_override_options (default_cpu)
 
   if (TARGET_TOC) 
     ASM_GENERATE_INTERNAL_LABEL (toc_label_name, "LCTOC", 1);
+
+  /* Arrange to save and restore machine status around nested functions.  */
+  init_machine_status = rs6000_init_machine_status;
+  mark_machine_status = rs6000_mark_machine_status;
+  free_machine_status = rs6000_free_machine_status;
 }
 
 void
@@ -3619,7 +3626,7 @@ rs6000_got_register (value)
   return pic_offset_table_rtx;
 }
 
-/* Functions to save and restore sysv_varargs_p.
+/* Functions to init, mark and free struct machine_function.
    These will be called, via pointer variables,
    from push_function_context and pop_function_context.  */
 
@@ -3627,9 +3634,15 @@ static void
 rs6000_init_machine_status (p)
      struct function *p;
 {
-  p->machine = (machine_function *) xmalloc (sizeof (machine_function));
+  p->machine = (machine_function *) xcalloc (1, sizeof (machine_function));
+}
 
-  p->machine->sysv_varargs_p = 0;
+static void
+rs6000_mark_machine_status (p)
+     struct function *p;
+{
+  if (p->machine)
+    ggc_mark_rtx (p->machine->ra_rtx);
 }
 
 static void
@@ -3643,17 +3656,6 @@ rs6000_free_machine_status (p)
   p->machine = NULL;
 }
 
-
-/* Do anything needed before RTL is emitted for each function.  */
-
-void
-rs6000_init_expanders ()
-{
-  /* Arrange to save and restore machine status around nested functions.  */
-  init_machine_status = rs6000_init_machine_status;
-  free_machine_status = rs6000_free_machine_status;
-}
-
 
 /* Print an operand.  Recognize special options, documented below.  */
 
@@ -4824,10 +4826,11 @@ rs6000_stack_info ()
   info_ptr->fp_size = 8 * (64 - info_ptr->first_fp_reg_save);
 
   /* Does this function call anything? */
-  info_ptr->calls_p = ! current_function_is_leaf;
+  info_ptr->calls_p = (! current_function_is_leaf
+		       || cfun->machine->ra_needs_full_frame);
 
   /* Determine if we need to save the link register */
-  if (regs_ever_live[LINK_REGISTER_REGNUM]
+  if (rs6000_ra_ever_killed ()
       || (DEFAULT_ABI == ABI_AIX && profile_flag)
 #ifdef TARGET_RELOCATABLE
       || (TARGET_RELOCATABLE && (get_pool_size () != 0))
@@ -5043,6 +5046,66 @@ debug_stack_info (info)
 
   fprintf (stderr, "\n");
 }
+
+rtx
+rs6000_return_addr (count, frame)
+     int count;
+     rtx frame;
+{
+  rtx init, reg;
+
+  /* Currently we don't optimize very well between prolog and body code and
+     for PIC code the code can be actually quite bad, so don't try to be
+     too clever here.  */
+  if (count != 0 || flag_pic != 0)
+    {
+      cfun->machine->ra_needs_full_frame = 1;
+      return
+	gen_rtx_MEM (Pmode,
+	  memory_address (Pmode,
+			  plus_constant (copy_to_reg (gen_rtx_MEM (Pmode,
+								   memory_address (Pmode, frame))),
+					 RETURN_ADDRESS_OFFSET)));
+    }
+
+  reg = cfun->machine->ra_rtx;
+  if (reg == NULL)
+    {
+      /* No rtx yet.  Invent one, and initialize it from LR in
+         the prologue.  */
+      reg = gen_reg_rtx (Pmode);
+      cfun->machine->ra_rtx = reg;
+      init = gen_rtx_SET (VOIDmode, reg,
+			  gen_rtx_REG (Pmode, LINK_REGISTER_REGNUM));
+
+      /* Emit the insn to the prologue with the other argument copies.  */
+      push_topmost_sequence ();
+      emit_insn_after (init, get_insns ());
+      pop_topmost_sequence ();
+    }
+
+  return reg;
+}
+
+static int
+rs6000_ra_ever_killed ()
+{
+  rtx top;
+
+#ifdef ASM_OUTPUT_MI_THUNK
+  if (current_function_is_thunk)
+    return 0;
+#endif
+  if (!cfun->machine->ra_rtx || cfun->machine->ra_needs_full_frame)
+    return regs_ever_live[LINK_REGISTER_REGNUM];
+
+  push_topmost_sequence ();
+  top = get_insns ();
+  pop_topmost_sequence ();
+
+  return reg_set_between_p (gen_rtx_REG (Pmode, LINK_REGISTER_REGNUM), 
+			    top, NULL_RTX);
+}
 
 /* Add a REG_MAYBE_DEAD note to the insn.  */
 static void
@@ -5553,7 +5616,7 @@ rs6000_emit_prologue()
 
   /* If we use the link register, get it into r0.  */
   if (info->lr_save_p)
-    emit_move_insn (gen_rtx_REG (Pmode, 0), 
+    emit_move_insn (gen_rtx_REG (Pmode, 0),
 		    gen_rtx_REG (Pmode, LINK_REGISTER_REGNUM));
 
   /* If we need to save CR, put it into r12.  */
diff --git a/gcc/config/rs6000/rs6000.h b/gcc/config/rs6000/rs6000.h
index 27079b3..54e9874 100644
--- a/gcc/config/rs6000/rs6000.h
+++ b/gcc/config/rs6000/rs6000.h
@@ -1229,10 +1229,6 @@ typedef struct rs6000_stack {
 /* Align an address */
 #define RS6000_ALIGN(n,a) (((n) + (a) - 1) & ~((a) - 1))
 
-/* Initialize data used by insn expanders.  This is called from
-   init_emit, once for each function, before code is generated. */
-#define INIT_EXPANDERS rs6000_init_expanders ()
-
 /* Size of V.4 varargs area in bytes */
 #define RS6000_VARARGS_SIZE \
   ((GP_ARG_NUM_REG * (TARGET_32BIT ? 4 : 8)) + (FP_ARG_NUM_REG * 8) + 8)
@@ -1388,6 +1384,10 @@ typedef struct machine_function
 {
   /* Whether a System V.4 varargs area was created.  */
   int sysv_varargs_p;
+  /* Set if a return address rtx for loading from LR was created.  */
+  struct rtx_def *ra_rtx;
+  /* Flags if __builtin_return_address (n) with n >= 1 was used.  */
+  int ra_needs_full_frame;
 } machine_function;
 
 /* Define a data type for recording info about an argument list
@@ -1649,17 +1649,12 @@ typedef struct rs6000_args
 /* The current return address is in link register (65).  The return address
    of anything farther back is accessed normally at an offset of 8 from the
    frame pointer.  */
-#define RETURN_ADDR_RTX(COUNT, FRAME)			\
-  (((COUNT) == -1)					\
-   ? gen_rtx_REG (Pmode, LINK_REGISTER_REGNUM)		\
-   : gen_rtx_MEM (Pmode,				\
-		  memory_address			\
-		  (Pmode, 				\
-		   plus_constant (copy_to_reg		\
-				  (gen_rtx_MEM (Pmode,	\
-						memory_address (Pmode, \
-								(FRAME)))), \
-				  RETURN_ADDRESS_OFFSET))))
+#define RETURN_ADDR_RTX(COUNT, FRAME)                 \
+  (rs6000_return_addr (COUNT, FRAME))
+
+extern struct rtx_def* rs6000_return_addr (int, struct rtx_def *rtx);
+
+
 
 /* Definitions for register eliminations.