From 045399546355a249baae4df245c77abf59e50a58 Mon Sep 17 00:00:00 2001
From: Hans-Peter Nilsson <hp@axis.com>
Date: Mon, 4 Apr 2005 22:43:34 +0000
Subject: [PATCH] CRIS epilogue as RTL.

	* config/cris/cris.md: Change all 0 in unspec 0 to
	CRIS_UNSPEC_PLT.
 	(CRIS_UNSPEC_PLT, CRIS_UNSPEC_FRAME_DEALLOC): New constants.
	("*cris_load_multiple", "cris_frame_deallocated_barrier"): New
	patterns.
	("return"): Change to define_expand.  Call cris_expand_return for
	actual expansion.
	("*return_expanded"): New pattern.
	("epilogue"): New define_expand.
	* config/cris/cris.h (PREDICATE_CODES): Add
	cris_load_multiple_op.
	* config/cris/cris.c (ASSERT_PLT_UNSPEC): Correct test for unspec
	type.
	(enum cris_retinsn_type): New.
	(struct machine_function): New member return_type.
	(TARGET_ASM_FUNCTION_EPILOGUE): Don't override.
	(cris_target_asm_function_epilogue): Remove, moving RTLified
	contents to...
	(cris_expand_epilogue): New function.
	(cris_reg_saved_in_regsave_area, cris_movem_load_rest_p,
	(cris_gen_movem_load, cris_load_multiple_op)
	(cris_return_address_on_stack_for_return, cris_expand_return): New
	functions.
	(cris_target_asm_function_prologue)
	(cris_initial_frame_pointer_offset): Call
	cris_reg_saved_in_regsave_area instead of complicated expression.
	Call cris_return_address_on_stack instead of an expression.
	(cris_print_operand) <case 'o', case 'O'>: New cases.
	(cris_return_address_on_stack): Change return-type to bool.
	(cris_simple_epilogue): Ditto.  Return false if registers are
	saved.
	* config/cris/cris-protos.h (cris_simple_epilogue)
	(cris_return_address_on_stack): Adjust prototype return type.
	(cris_gen_movem_load, cris_expand_epilogue, cris_expand_return)
	(cris_return_address_on_stack_for_return): New prototypes.

From-SVN: r97580
---
 gcc/ChangeLog                 |  39 ++
 gcc/config/cris/cris-protos.h |  10 +-
 gcc/config/cris/cris.c        | 753 ++++++++++++++++++++--------------
 gcc/config/cris/cris.h        |   2 +
 gcc/config/cris/cris.md       | 123 +++---
 5 files changed, 565 insertions(+), 362 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 63fbd069d364..7f512e2575a4 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,42 @@
+2005-04-05  Hans-Peter Nilsson  <hp@axis.com>
+
+	CRIS epilogue as RTL.
+	* config/cris/cris.md: Change all 0 in unspec 0 to
+	CRIS_UNSPEC_PLT.
+ 	(CRIS_UNSPEC_PLT, CRIS_UNSPEC_FRAME_DEALLOC): New constants.
+	("*cris_load_multiple", "cris_frame_deallocated_barrier"): New
+	patterns.
+	("return"): Change to define_expand.  Call cris_expand_return for
+	actual expansion.
+	("*return_expanded"): New pattern.
+	("epilogue"): New define_expand.
+	* config/cris/cris.h (PREDICATE_CODES): Add
+	cris_load_multiple_op.
+	* config/cris/cris.c (ASSERT_PLT_UNSPEC): Correct test for unspec
+	type.
+	(enum cris_retinsn_type): New.
+	(struct machine_function): New member return_type.
+	(TARGET_ASM_FUNCTION_EPILOGUE): Don't override.
+	(cris_target_asm_function_epilogue): Remove, moving RTLified
+	contents to...
+	(cris_expand_epilogue): New function.
+	(cris_reg_saved_in_regsave_area, cris_movem_load_rest_p,
+	(cris_gen_movem_load, cris_load_multiple_op)
+	(cris_return_address_on_stack_for_return, cris_expand_return): New
+	functions.
+	(cris_target_asm_function_prologue)
+	(cris_initial_frame_pointer_offset): Call
+	cris_reg_saved_in_regsave_area instead of complicated expression.
+	Call cris_return_address_on_stack instead of an expression.
+	(cris_print_operand) <case 'o', case 'O'>: New cases.
+	(cris_return_address_on_stack): Change return-type to bool.
+	(cris_simple_epilogue): Ditto.  Return false if registers are
+	saved.
+	* config/cris/cris-protos.h (cris_simple_epilogue)
+	(cris_return_address_on_stack): Adjust prototype return type.
+	(cris_gen_movem_load, cris_expand_epilogue, cris_expand_return)
+	(cris_return_address_on_stack_for_return): New prototypes.
+
 2005-04-04  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* config/frv/frv.h (PREDICATE_CODES): Add CONST to
diff --git a/gcc/config/cris/cris-protos.h b/gcc/config/cris/cris-protos.h
index e47327ffb1eb..ecd963280922 100644
--- a/gcc/config/cris/cris-protos.h
+++ b/gcc/config/cris/cris-protos.h
@@ -27,7 +27,7 @@ Boston, MA 02111-1307, USA.  */
 #endif
 
 extern void cris_conditional_register_usage (void);
-extern int cris_simple_epilogue (void);
+extern bool cris_simple_epilogue (void);
 #ifdef RTX_CODE
 extern const char *cris_op_str (rtx);
 extern void cris_notice_update_cc (rtx, rtx);
@@ -44,12 +44,14 @@ extern int cris_symbol (rtx);
 extern void cris_asm_output_symbol_ref (FILE *, rtx);
 extern bool cris_output_addr_const_extra (FILE *, rtx);
 extern int cris_cfun_uses_pic_table (void);
+extern rtx cris_gen_movem_load (rtx, rtx, int);
 #endif /* RTX_CODE */
 extern void cris_asm_output_label_ref (FILE *, char *);
 extern void cris_target_asm_named_section (const char *, unsigned int, tree);
-
-extern int cris_return_address_on_stack (void);
-
+extern void cris_expand_epilogue (void);
+extern void cris_expand_return (bool);
+extern bool cris_return_address_on_stack_for_return (void);
+extern bool cris_return_address_on_stack (void);
 extern void cris_pragma_expand_mul (struct cpp_reader *);
 
 /* Need one that returns an int; usable in expressions.  */
diff --git a/gcc/config/cris/cris.c b/gcc/config/cris/cris.c
index 314ae0f7e4e5..a9512a606b1d 100644
--- a/gcc/config/cris/cris.c
+++ b/gcc/config/cris/cris.c
@@ -54,7 +54,7 @@ Boston, MA 02111-1307, USA.  */
 #define ASSERT_PLT_UNSPEC(x)					\
   do								\
     {								\
-      if (XEXP (x, 1) != NULL_RTX				\
+      if (XINT (x, 1) != CRIS_UNSPEC_PLT			\
 	  || (GET_CODE (XVECEXP (x, 0, 0)) != SYMBOL_REF	\
 	      && GET_CODE (XVECEXP (x, 0, 0)) != LABEL_REF))	\
 	abort ();						\
@@ -67,10 +67,14 @@ Boston, MA 02111-1307, USA.  */
       return;					\
     } while (0)
 
+enum cris_retinsn_type
+ { CRIS_RETINSN_UNKNOWN = 0, CRIS_RETINSN_RET, CRIS_RETINSN_JUMP };
+
 /* Per-function machine data.  */
 struct machine_function GTY(())
  {
    int needs_return_address_on_stack;
+   enum cris_retinsn_type return_type;
  };
 
 /* This little fix suppresses the 'u' or 's' when '%e' in assembly
@@ -109,10 +113,12 @@ static int saved_regs_mentioned (rtx);
 
 static void cris_target_asm_function_prologue (FILE *, HOST_WIDE_INT);
 
-static void cris_target_asm_function_epilogue (FILE *, HOST_WIDE_INT);
-
 static void cris_operand_lossage (const char *, rtx);
 
+static int cris_reg_saved_in_regsave_area  (unsigned int, bool);
+
+static int cris_movem_load_rest_p (rtx, int);
+
 static void cris_asm_output_mi_thunk
   (FILE *, tree, HOST_WIDE_INT, HOST_WIDE_INT, tree);
 
@@ -168,9 +174,6 @@ int cris_cpu_version = CRIS_DEFAULT_CPU_VERSION;
 #undef TARGET_ASM_FUNCTION_PROLOGUE
 #define TARGET_ASM_FUNCTION_PROLOGUE cris_target_asm_function_prologue
 
-#undef TARGET_ASM_FUNCTION_EPILOGUE
-#define TARGET_ASM_FUNCTION_EPILOGUE cris_target_asm_function_epilogue
-
 #undef TARGET_ASM_OUTPUT_MI_THUNK
 #define TARGET_ASM_OUTPUT_MI_THUNK cris_asm_output_mi_thunk
 #undef TARGET_ASM_CAN_OUTPUT_MI_THUNK
@@ -454,7 +457,7 @@ cris_general_operand_or_plt_symbol (rtx op, enum machine_mode mode)
    (MEM (cris_general_operand_or_symbol)).  The second one isn't a valid
    memory_operand, so we need this predicate to recognize call
    destinations before we change them to a PLT operand (by wrapping in
-   UNSPEC 0).  */
+   UNSPEC CRIS_UNSPEC_PLT).  */
 
 int
 cris_mem_call_operand (rtx op, enum machine_mode mode)
@@ -472,6 +475,94 @@ cris_mem_call_operand (rtx op, enum machine_mode mode)
   return cris_general_operand_or_symbol (xmem, GET_MODE (op));
 }
 
+/* Helper for cris_load_multiple_op and cris_ret_movem_op.  */
+
+static int
+cris_movem_load_rest_p (rtx op, int offs)
+{
+  unsigned int reg_count = XVECLEN (op, 0) - offs;
+  rtx src_addr;
+  int i;
+  rtx elt;
+  int setno;
+  int regno_dir = 1;
+  unsigned int regno = 0;
+
+  /* Perform a quick check so we don't blow up below.  FIXME: Adjust for
+     other than (MEM reg).  */
+  if (reg_count <= 1
+      || GET_CODE (XVECEXP (op, 0, offs)) != SET
+      || GET_CODE (SET_DEST (XVECEXP (op, 0, offs))) != REG
+      || GET_CODE (SET_SRC (XVECEXP (op, 0, offs))) != MEM)
+    return 0;
+
+  /* Check a possible post-inc indicator.  */
+  if (GET_CODE (SET_SRC (XVECEXP (op, 0, offs + 1))) == PLUS)
+    {
+      rtx reg = XEXP (SET_SRC (XVECEXP (op, 0, offs + 1)), 0);
+      rtx inc = XEXP (SET_SRC (XVECEXP (op, 0, offs + 1)), 1);
+
+      reg_count--;
+
+      if (reg_count == 1
+	  || !REG_P (reg)
+	  || !REG_P (SET_DEST (XVECEXP (op, 0, offs + 1)))
+	  || REGNO (reg) != REGNO (SET_DEST (XVECEXP (op, 0, offs + 1)))
+	  || GET_CODE (inc) != CONST_INT
+	  || INTVAL (inc) != (HOST_WIDE_INT) reg_count * 4)
+	return 0;
+      i = offs + 2;
+    }
+  else
+    i = offs + 1;
+
+  /* FIXME: These two only for pre-v32.  */
+  regno_dir = -1;
+  regno = reg_count - 1;
+
+  elt = XVECEXP (op, 0, offs);
+  src_addr = XEXP (SET_SRC (elt), 0);
+
+  if (GET_CODE (elt) != SET
+      || GET_CODE (SET_DEST (elt)) != REG
+      || GET_MODE (SET_DEST (elt)) != SImode
+      || REGNO (SET_DEST (elt)) != regno
+      || GET_CODE (SET_SRC (elt)) != MEM
+      || GET_MODE (SET_SRC (elt)) != SImode
+      || !memory_address_p (SImode, src_addr))
+    return 0;
+
+  for (setno = 1; i < XVECLEN (op, 0); setno++, i++)
+    {
+      rtx elt = XVECEXP (op, 0, i);
+      regno += regno_dir;
+
+      if (GET_CODE (elt) != SET
+	  || GET_CODE (SET_DEST (elt)) != REG
+	  || GET_MODE (SET_DEST (elt)) != SImode
+	  || REGNO (SET_DEST (elt)) != regno
+	  || GET_CODE (SET_SRC (elt)) != MEM
+	  || GET_MODE (SET_SRC (elt)) != SImode
+	  || GET_CODE (XEXP (SET_SRC (elt), 0)) != PLUS
+	  || ! rtx_equal_p (XEXP (XEXP (SET_SRC (elt), 0), 0), src_addr)
+	  || GET_CODE (XEXP (XEXP (SET_SRC (elt), 0), 1)) != CONST_INT
+	  || INTVAL (XEXP (XEXP (SET_SRC (elt), 0), 1)) != setno * 4)
+	return 0;
+    }
+
+  return 1;
+}
+
+/* Predicate for the parallel contents in a movem from-memory.  */
+
+int
+cris_load_multiple_op (op, mode)
+     rtx op;
+     enum machine_mode mode ATTRIBUTE_UNUSED;
+{
+  return cris_movem_load_rest_p (op, 0);
+}
+
 /* The CONDITIONAL_REGISTER_USAGE worker.  */
 
 void
@@ -657,6 +748,33 @@ cris_fatal (char *arg)
   return 0;
 }
 
+/* Return nonzero if REGNO is an ordinary register that *needs* to be
+   saved together with other registers, possibly by a MOVEM instruction,
+   or is saved for target-independent reasons.  There may be
+   target-dependent reasons to save the register anyway; this is just a
+   wrapper for a complicated conditional.  */
+
+static int
+cris_reg_saved_in_regsave_area (unsigned int regno, bool got_really_used)
+{
+  return
+    (((regs_ever_live[regno]
+       && !call_used_regs[regno])
+      || (regno == PIC_OFFSET_TABLE_REGNUM
+	  && (got_really_used
+	      /* It is saved anyway, if there would be a gap.  */
+	      || (flag_pic
+		  && regs_ever_live[regno + 1]
+		  && !call_used_regs[regno + 1]))))
+     && (regno != FRAME_POINTER_REGNUM || !frame_pointer_needed)
+     && regno != CRIS_SRP_REGNUM)
+    || (current_function_calls_eh_return
+	&& (regno == EH_RETURN_DATA_REGNO (0)
+	    || regno == EH_RETURN_DATA_REGNO (1)
+	    || regno == EH_RETURN_DATA_REGNO (2)
+	    || regno == EH_RETURN_DATA_REGNO (3)));
+}
+
 /* This variable belongs to cris_target_asm_function_prologue but must
    be located outside it for GTY reasons.  */
 static GTY(()) unsigned long cfa_label_num = 0;
@@ -676,9 +794,8 @@ cris_target_asm_function_prologue (FILE *file, HOST_WIDE_INT size)
   int faked_args_size = 0;
   int cfa_write_offset = 0;
   static char cfa_label[30];
-  int return_address_on_stack
-    = regs_ever_live[CRIS_SRP_REGNUM]
-    || cfun->machine->needs_return_address_on_stack != 0;
+  bool return_address_on_stack = cris_return_address_on_stack ();
+  bool got_really_used = current_function_uses_pic_offset_table;
 
   /* Don't do anything if no prologues or epilogues are wanted.  */
   if (!TARGET_PROLOGUE_EPILOGUE)
@@ -771,21 +888,7 @@ cris_target_asm_function_prologue (FILE *file, HOST_WIDE_INT size)
      to be saved.  */
   for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
     {
-      if ((((regs_ever_live[regno]
-	     && !call_used_regs[regno])
-	    || (regno == (int) PIC_OFFSET_TABLE_REGNUM
-		&& (current_function_uses_pic_offset_table
-		    /* It is saved anyway, if there would be a gap.  */
-		    || (flag_pic
-			&& regs_ever_live[regno + 1]
-			&& !call_used_regs[regno + 1]))))
-	   && (regno != FRAME_POINTER_REGNUM || !frame_pointer_needed)
-	   && regno != CRIS_SRP_REGNUM)
-	  || (current_function_calls_eh_return
-	      && (regno == EH_RETURN_DATA_REGNO (0)
-		  || regno == EH_RETURN_DATA_REGNO (1)
-		  || regno == EH_RETURN_DATA_REGNO (2)
-		  || regno == EH_RETURN_DATA_REGNO (3))))
+      if (cris_reg_saved_in_regsave_area (regno, got_really_used))
 	{
 	  /* Check if movem may be used for registers so far.  */
 	  if (regno == last_movem_reg + 1)
@@ -997,239 +1100,6 @@ saved_regs_mentioned (rtx x)
   return 0;
 }
 
-/* Textual function epilogue.  */
-
-static void
-cris_target_asm_function_epilogue (FILE *file, HOST_WIDE_INT size)
-{
-  int regno;
-  int last_movem_reg = -1;
-  rtx insn = get_last_insn ();
-  int argspace_offset = current_function_outgoing_args_size;
-  int pretend =	 current_function_pretend_args_size;
-  int return_address_on_stack
-    = regs_ever_live[CRIS_SRP_REGNUM]
-    || cfun->machine->needs_return_address_on_stack != 0;
-  char save_last[80];
-
-  save_last[0] = 0;
-
-  if (!TARGET_PROLOGUE_EPILOGUE)
-    return;
-
-  if (TARGET_PDEBUG)
-    fprintf (file, ";;\n");
-
-  /* Align byte count of stack frame.  */
-  if (TARGET_STACK_ALIGN)
-    size = TARGET_ALIGN_BY_32 ? (size + 3) & ~3 : (size + 1) & ~1;
-
-  /* If the last insn was a BARRIER, we don't have to write any code,
-     then all returns were covered by "return" insns.  */
-  if (GET_CODE (insn) == NOTE)
-    insn = prev_nonnote_insn (insn);
-  if (insn
-      && (GET_CODE (insn) == BARRIER
-	  /* We must make sure that the insn really is a "return" and
-	     not a conditional branch.  Try to match the return exactly,
-	     and if it doesn't match, assume it is a conditional branch
-	     (and output an epilogue).  */
-	  || (GET_CODE (insn) == JUMP_INSN
-	      && GET_CODE (PATTERN (insn)) == RETURN)))
-    {
-      if (TARGET_PDEBUG)
-	fprintf (file, ";;;;;\n");
-      return;
-    }
-
-  /* Check how many saved regs we can movem.  They start at r0 and must
-     be contiguous.  */
-  for (regno = 0;
-       regno < FIRST_PSEUDO_REGISTER;
-       regno++)
-    if ((((regs_ever_live[regno]
-	   && !call_used_regs[regno])
-	  || (regno == (int) PIC_OFFSET_TABLE_REGNUM
-	      && (current_function_uses_pic_offset_table
-		  /* It is saved anyway, if there would be a gap.  */
-		  || (flag_pic
-		      && regs_ever_live[regno + 1]
-		      && !call_used_regs[regno + 1]))))
-	 && (regno != FRAME_POINTER_REGNUM || !frame_pointer_needed)
-	 && regno != CRIS_SRP_REGNUM)
-	|| (current_function_calls_eh_return
-	    && (regno == EH_RETURN_DATA_REGNO (0)
-		|| regno == EH_RETURN_DATA_REGNO (1)
-		|| regno == EH_RETURN_DATA_REGNO (2)
-		|| regno == EH_RETURN_DATA_REGNO (3))))
-
-      {
-	if (regno == last_movem_reg + 1)
-	  last_movem_reg++;
-	else
-	  break;
-      }
-
-  for (regno = FIRST_PSEUDO_REGISTER - 1;
-       regno > last_movem_reg;
-       regno--)
-    if ((((regs_ever_live[regno]
-	   && !call_used_regs[regno])
-	  || (regno == (int) PIC_OFFSET_TABLE_REGNUM
-	      && (current_function_uses_pic_offset_table
-		  /* It is saved anyway, if there would be a gap.  */
-		  || (flag_pic
-		      && regs_ever_live[regno + 1]
-		      && !call_used_regs[regno + 1]))))
-	 && (regno != FRAME_POINTER_REGNUM || !frame_pointer_needed)
-	 && regno != CRIS_SRP_REGNUM)
-	|| (current_function_calls_eh_return
-	    && (regno == EH_RETURN_DATA_REGNO (0)
-		|| regno == EH_RETURN_DATA_REGNO (1)
-		|| regno == EH_RETURN_DATA_REGNO (2)
-		|| regno == EH_RETURN_DATA_REGNO (3))))
-      {
-	if (argspace_offset)
-	  {
-	    /* There is an area for outgoing parameters located before
-	       the saved registers.  We have to adjust for that.  */
-	    fprintf (file, "\tAdd%s %d,$sp\n",
-		     ADDITIVE_SIZE_MODIFIER (argspace_offset),
-		     argspace_offset);
-
-	    /* Make sure we only do this once.  */
-	    argspace_offset = 0;
-	  }
-
-	/* Flush previous non-movem:ed registers.  */
-	if (*save_last)
-	  fprintf (file, save_last);
-	sprintf (save_last, "\tPop $%s\n", reg_names[regno]);
-      }
-
-  if (last_movem_reg != -1)
-    {
-      if (argspace_offset)
-	{
-	  /* Adjust for the outgoing parameters area, if that's not
-	     handled yet.  */
-	  if (*save_last)
-	    {
-	      fprintf (file, save_last);
-	      *save_last = 0;
-	    }
-
-	  fprintf (file, "\tAdd%s %d,$sp\n",
-		   ADDITIVE_SIZE_MODIFIER (argspace_offset),
-		   argspace_offset);
-	  argspace_offset = 0;
-	}
-      /* Flush previous non-movem:ed registers.  */
-      else if (*save_last)
-	fprintf (file, save_last);
-      sprintf (save_last, "\tmovem [$sp+],$%s\n", reg_names[last_movem_reg]);
-    }
-
-  /* Restore frame pointer if necessary.  */
-  if (frame_pointer_needed)
-    {
-      if (*save_last)
-	fprintf (file, save_last);
-
-      fprintf (file, "\tmove.d $%s,$sp\n",
-	       reg_names[FRAME_POINTER_REGNUM]);
-      sprintf (save_last, "\tPop $%s\n",
-	       reg_names[FRAME_POINTER_REGNUM]);
-    }
-  else
-    {
-      /* If there was no frame-pointer to restore sp from, we must
-	 explicitly deallocate local variables.  */
-
-      /* Handle space for outgoing parameters that hasn't been handled
-	 yet.  */
-      size += argspace_offset;
-
-      if (size)
-	{
-	  if (*save_last)
-	    fprintf (file, save_last);
-
-	  sprintf (save_last, "\tadd%s "HOST_WIDE_INT_PRINT_DEC",$sp\n",
-		   ADDITIVE_SIZE_MODIFIER (size), size);
-	}
-
-      /* If the size was not in the range for a "quick", we must flush
-	 it here.  */
-      if (size > 63)
-	{
-	  fprintf (file, save_last);
-	  *save_last = 0;
-	}
-    }
-
-  /* If this function has no pushed register parameters
-     (stdargs/varargs), and if it is not a leaf function, then we can
-     just jump-return here.  */
-  if (return_address_on_stack && pretend == 0)
-    {
-      if (*save_last)
-	fprintf (file, save_last);
-      *save_last = 0;
-
-      if (current_function_calls_eh_return)
-	{
-	  /* The installed EH-return address is in *this* frame, so we
-	     need to pop it before we return.  */
-	  fprintf (file, "\tpop $srp\n");
-	  fprintf (file, "\tret\n");
-	  fprintf (file, "\tadd.d $%s,$sp\n", reg_names[CRIS_STACKADJ_REG]);
-	}
-      else
-	fprintf (file, "\tJump [$sp+]\n");
-
-      return;
-    }
-
-  /* Rather than add current_function_calls_eh_return conditions
-     everywhere in the following code (and not be able to test it
-     thoroughly), assert the assumption that all usage of
-     __builtin_eh_return are handled above.  */
-  if (current_function_calls_eh_return)
-    internal_error ("unexpected function type needing stack adjustment for\
- __builtin_eh_return");
-
-  /* If we pushed some register parameters, then adjust the stack for
-     them.  */
-  if (pretend)
-    {
-      /* Since srp is stored on the way, we need to restore it first.  */
-      if (return_address_on_stack)
-	{
-	  if (*save_last)
-	    fprintf (file, save_last);
-	  *save_last = 0;
-
-	  fprintf (file, "\tpop $srp\n");
-	}
-
-      if (*save_last)
-	fprintf (file, save_last);
-
-      sprintf (save_last, "\tadd%s %d,$sp\n",
-	       ADDITIVE_SIZE_MODIFIER (pretend), pretend);
-    }
-
-  fprintf (file, "\tRet\n");
-
-  /* If the GCC did not do it, we have to use whatever insn we have, or
-     a nop.  */
-  if (*save_last)
-    fprintf (file, save_last);
-  else
-    fprintf (file, "\tnOp\n");
-}
-
 /* The PRINT_OPERAND worker.  */
 
 void
@@ -1272,6 +1142,49 @@ cris_print_operand (FILE *file, rtx x, int code)
       cris_pic_sympart_only--;
       return;
 
+    case 'o':
+      {
+	/* A movem modifier working on a parallel; output the register
+	   name.  */
+	int regno;
+
+	if (GET_CODE (x) != PARALLEL)
+	  LOSE_AND_RETURN ("invalid operand for 'o' modifier", x);
+
+	/* The second item can be (set reg (plus reg const)) to denote a
+	   postincrement.  */
+	regno
+	  = (GET_CODE (SET_SRC (XVECEXP (x, 0, 1))) == PLUS
+	     ? XVECLEN (x, 0) - 2
+	     : XVECLEN (x, 0) - 1);
+
+	fprintf (file, "$%s", reg_names [regno]);
+      }
+      return;
+
+    case 'O':
+      {
+	/* A similar movem modifier; output the memory operand.  */
+	rtx addr;
+
+	if (GET_CODE (x) != PARALLEL)
+	  LOSE_AND_RETURN ("invalid operand for 'O' modifier", x);
+
+	/* The lowest mem operand is in the first item, but perhaps it
+	   needs to be output as postincremented.  */
+	addr = GET_CODE (SET_SRC (XVECEXP (x, 0, 0))) == MEM
+	  ? XEXP (SET_SRC (XVECEXP (x, 0, 0)), 0)
+	  : XEXP (SET_DEST (XVECEXP (x, 0, 0)), 0);
+
+	/* The second item can be a (set reg (plus reg const)) to denote a
+	   post-increment.  */
+	if (GET_CODE (SET_SRC (XVECEXP (x, 0, 1))) == PLUS)
+	  addr = gen_rtx_POST_INC (SImode, addr);
+
+	output_address (addr);
+      }
+      return;
+
     case 'P':
       /* Print the PIC register.  Applied to a GOT-less PIC symbol for
          sanity.  */
@@ -1647,10 +1560,21 @@ cris_return_addr_rtx (int count, rtx frameaddr ATTRIBUTE_UNUSED)
 /* Accessor used in cris.md:return because cfun->machine isn't available
    there.  */
 
-int
+bool
 cris_return_address_on_stack ()
 {
-  return cfun->machine->needs_return_address_on_stack;
+  return regs_ever_live[CRIS_SRP_REGNUM]
+    || cfun->machine->needs_return_address_on_stack;
+}
+
+/* Accessor used in cris.md:return because cfun->machine isn't available
+   there.  */
+
+bool
+cris_return_address_on_stack_for_return ()
+{
+  return cfun->machine->return_type == CRIS_RETINSN_RET ? false
+    : cris_return_address_on_stack ();
 }
 
 /* This used to be the INITIAL_FRAME_POINTER_OFFSET worker; now only
@@ -1663,24 +1587,11 @@ cris_initial_frame_pointer_offset (void)
 
   /* Initial offset is 0 if we don't have a frame pointer.  */
   int offs = 0;
+  bool got_really_used = current_function_uses_pic_offset_table;
 
   /* And 4 for each register pushed.  */
   for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
-    if ((((regs_ever_live[regno]
-	   && !call_used_regs[regno])
-	  || (regno == (int) PIC_OFFSET_TABLE_REGNUM
-	      && (current_function_uses_pic_offset_table
-		  /* It is saved anyway, if there would be a gap.  */
-		  || (flag_pic
-		      && regs_ever_live[regno + 1]
-		      && !call_used_regs[regno + 1]))))
-	 && (regno != FRAME_POINTER_REGNUM || !frame_pointer_needed)
-	 && regno != CRIS_SRP_REGNUM)
-	|| (current_function_calls_eh_return
-	    && (regno == EH_RETURN_DATA_REGNO (0)
-		|| regno == EH_RETURN_DATA_REGNO (1)
-		|| regno == EH_RETURN_DATA_REGNO (2)
-		|| regno == EH_RETURN_DATA_REGNO (3))))
+    if (cris_reg_saved_in_regsave_area (regno, got_really_used))
       offs += 4;
 
   /* And then, last, we add the locals allocated.  */
@@ -1709,9 +1620,7 @@ cris_initial_elimination_offset (int fromreg, int toreg)
 
   /* We should be able to use regs_ever_live and related prologue
      information here, or alpha should not as well.  */
-  int return_address_on_stack
-    = regs_ever_live[CRIS_SRP_REGNUM]
-    || cfun->machine->needs_return_address_on_stack != 0;
+  bool return_address_on_stack = cris_return_address_on_stack ();
 
   /* Here we act as if the frame-pointer were needed.  */
   int ap_fp_offset = 4 + (return_address_on_stack ? 4 : 0);
@@ -2003,15 +1912,15 @@ cris_notice_update_cc (rtx exp, rtx insn)
 }
 
 /* Return != 0 if the return sequence for the current function is short,
-   like "ret" or "jump [sp+]".  Prior to reloading, we can't tell how
-   many registers must be saved, so return 0 then.  */
+   like "ret" or "jump [sp+]".  Prior to reloading, we can't tell if
+   registers must be saved, so return 0 then.  */
 
-int
+bool
 cris_simple_epilogue (void)
 {
-  int regno;
-  int reglimit = STACK_POINTER_REGNUM;
-  int lastreg = -1;
+  unsigned int regno;
+  unsigned int reglimit = STACK_POINTER_REGNUM;
+  bool got_really_used = current_function_uses_pic_offset_table;
 
   if (! reload_completed
       || frame_pointer_needed
@@ -2024,25 +1933,36 @@ cris_simple_epilogue (void)
       /* If we're not supposed to emit prologue and epilogue, we must
 	 not emit return-type instructions.  */
       || !TARGET_PROLOGUE_EPILOGUE)
-    return 0;
+    return false;
 
-  /* We allow a "movem [sp+],rN" to sit in front if the "jump [sp+]" or
-     in the delay-slot of the "ret".  */
+  /* No simple epilogue if there are saved registers.  */
   for (regno = 0; regno < reglimit; regno++)
-    if ((regs_ever_live[regno] && ! call_used_regs[regno])
-	|| (regno == (int) PIC_OFFSET_TABLE_REGNUM
-	    && (current_function_uses_pic_offset_table
-		/* It is saved anyway, if there would be a gap.  */
-		|| (flag_pic
-		    && regs_ever_live[regno + 1]
-		    && !call_used_regs[regno + 1]))))
-      {
-	if (lastreg != regno - 1)
-	  return 0;
-	lastreg = regno;
-      }
+    if (cris_reg_saved_in_regsave_area (regno, got_really_used))
+      return false;
 
-  return 1;
+  return true;
+}
+
+/* Expand a return insn (just one insn) marked as using SRP or stack
+   slot depending on parameter ON_STACK.  */
+
+void
+cris_expand_return (bool on_stack)
+{
+  /* FIXME: emit a parallel with a USE for SRP or the stack-slot, to
+     tell "ret" from "jump [sp+]".  Some, but not all, other parts of
+     GCC expect just (return) to do the right thing when optimizing, so
+     we do that until they're fixed.  Currently, all return insns in a
+     function must be the same (not really a limiting factor) so we need
+     to check that it doesn't change half-way through.  */
+  emit_jump_insn (gen_rtx_RETURN (VOIDmode));
+
+  if ((cfun->machine->return_type == CRIS_RETINSN_RET && on_stack)
+      || (cfun->machine->return_type == CRIS_RETINSN_JUMP && !on_stack))
+    abort ();
+
+  cfun->machine->return_type
+    = on_stack ? CRIS_RETINSN_JUMP : CRIS_RETINSN_RET;
 }
 
 /* Compute a (partial) cost for rtx X.  Return true if the complete
@@ -2886,6 +2806,239 @@ cris_split_movdx (rtx *operands)
   return val;
 }
 
+/* The expander for the epilogue pattern.  */
+
+void
+cris_expand_epilogue (void)
+{
+  int regno;
+  int size = get_frame_size ();
+  int last_movem_reg = -1;
+  int argspace_offset = current_function_outgoing_args_size;
+  int pretend =	 current_function_pretend_args_size;
+  rtx mem;
+  bool return_address_on_stack = cris_return_address_on_stack ();
+  /* A reference may have been optimized out
+     (like the abort () in fde_split in unwind-dw2-fde.c, at least 3.2.1)
+     so check that it's still used.  */
+  int got_really_used = current_function_uses_pic_offset_table;
+  int n_movem_regs = 0;
+
+  if (!TARGET_PROLOGUE_EPILOGUE)
+    return;
+
+  /* Align byte count of stack frame.  */
+  if (TARGET_STACK_ALIGN)
+    size = TARGET_ALIGN_BY_32 ? (size + 3) & ~3 : (size + 1) & ~1;
+
+  /* Check how many saved regs we can movem.  They start at r0 and must
+     be contiguous.  */
+  for (regno = 0;
+       regno < FIRST_PSEUDO_REGISTER;
+       regno++)
+    if (cris_reg_saved_in_regsave_area (regno, got_really_used))
+      {
+	n_movem_regs++;
+
+	if (regno == last_movem_reg + 1)
+	  last_movem_reg = regno;
+	else
+	  break;
+      }
+
+  /* If there was only one register that really needed to be saved
+     through movem, don't use movem.  */
+  if (n_movem_regs == 1)
+    last_movem_reg = -1;
+
+  /* Now emit "normal" move insns for all regs higher than the movem
+     regs.  */
+  for (regno = FIRST_PSEUDO_REGISTER - 1;
+       regno > last_movem_reg;
+       regno--)
+    if (cris_reg_saved_in_regsave_area (regno, got_really_used))
+      {
+	if (argspace_offset)
+	  {
+	    /* There is an area for outgoing parameters located before
+	       the saved registers.  We have to adjust for that.  */
+	    emit_insn (gen_rtx_SET (VOIDmode,
+				    stack_pointer_rtx,
+				    plus_constant (stack_pointer_rtx,
+						   argspace_offset)));
+	    /* Make sure we only do this once.  */
+	    argspace_offset = 0;
+	  }
+
+	mem = gen_rtx_MEM (SImode, gen_rtx_POST_INC (SImode,
+						     stack_pointer_rtx));
+	set_mem_alias_set (mem, get_frame_alias_set ());
+	emit_move_insn (gen_rtx_raw_REG (SImode, regno), mem);
+      }
+
+  /* If we have any movem-restore, do it now.  */
+  if (last_movem_reg != -1)
+    {
+      if (argspace_offset)
+	{
+	  emit_insn (gen_rtx_SET (VOIDmode,
+				  stack_pointer_rtx,
+				  plus_constant (stack_pointer_rtx,
+						 argspace_offset)));
+	  argspace_offset = 0;
+	}
+
+      mem = gen_rtx_MEM (SImode,
+			 gen_rtx_POST_INC (SImode, stack_pointer_rtx));
+      set_mem_alias_set (mem, get_frame_alias_set ());
+      emit_insn (cris_gen_movem_load (mem, GEN_INT (last_movem_reg + 1), 0));
+    }
+
+  /* If we don't clobber all of the allocated stack area (we've already
+     deallocated saved registers), GCC might want to schedule loads from
+     the stack to *after* the stack-pointer restore, which introduces an
+     interrupt race condition.  This happened for the initial-value
+     SRP-restore for g++.dg/eh/registers1.C (noticed by inspection of
+     other failure for that test).  It also happened for the stack slot
+     for the return value in (one version of)
+     linux/fs/dcache.c:__d_lookup, at least with "-O2
+     -fno-omit-frame-pointer".  */
+
+  /* Restore frame pointer if necessary.  */
+  if (frame_pointer_needed)
+    {
+      emit_insn (gen_cris_frame_deallocated_barrier ());
+
+      emit_move_insn (stack_pointer_rtx, frame_pointer_rtx);
+      mem = gen_rtx_MEM (SImode, gen_rtx_POST_INC (SImode,
+						   stack_pointer_rtx));
+      set_mem_alias_set (mem, get_frame_alias_set ());
+      emit_move_insn (frame_pointer_rtx, mem);
+    }
+  else if ((size + argspace_offset) != 0)
+    {
+      emit_insn (gen_cris_frame_deallocated_barrier ());
+
+      /* If there was no frame-pointer to restore sp from, we must
+	 explicitly deallocate local variables.  */
+
+      /* Handle space for outgoing parameters that hasn't been handled
+	 yet.  */
+      size += argspace_offset;
+
+      emit_insn (gen_rtx_SET (VOIDmode,
+			      stack_pointer_rtx,
+			      plus_constant (stack_pointer_rtx, size)));
+    }
+
+  /* If this function has no pushed register parameters
+     (stdargs/varargs), and if it is not a leaf function, then we have
+     the return address on the stack.  */
+  if (return_address_on_stack && pretend == 0)
+    {
+      if (current_function_calls_eh_return)
+	{
+	  rtx mem;
+	  rtx srpreg = gen_rtx_raw_REG (SImode, CRIS_SRP_REGNUM);
+	  mem = gen_rtx_MEM (SImode,
+			     gen_rtx_POST_INC (SImode,
+					       stack_pointer_rtx));
+	  set_mem_alias_set (mem, get_frame_alias_set ());
+	  emit_move_insn (srpreg, mem);
+
+	  emit_insn (gen_addsi3 (stack_pointer_rtx,
+				 stack_pointer_rtx,
+				 gen_rtx_raw_REG (SImode,
+						  CRIS_STACKADJ_REG)));
+	  cris_expand_return (false);
+	}
+      else
+	cris_expand_return (true);
+
+      return;
+    }
+
+  /* If we pushed some register parameters, then adjust the stack for
+     them.  */
+  if (pretend != 0)
+    {
+      /* If SRP is stored on the way, we need to restore it first.  */
+      if (return_address_on_stack)
+	{
+	  rtx mem;
+	  rtx srpreg = gen_rtx_raw_REG (SImode, CRIS_SRP_REGNUM);
+	  mem = gen_rtx_MEM (SImode,
+			     gen_rtx_POST_INC (SImode,
+					       stack_pointer_rtx));
+	  set_mem_alias_set (mem, get_frame_alias_set ());
+	  emit_move_insn (srpreg, mem);
+	}
+
+      emit_insn (gen_rtx_SET (VOIDmode,
+			      stack_pointer_rtx,
+			      plus_constant (stack_pointer_rtx, pretend)));
+    }
+
+  /* Perform the "physical" unwinding that the EH machinery calculated.  */
+  if (current_function_calls_eh_return)
+    emit_insn (gen_addsi3 (stack_pointer_rtx,
+			   stack_pointer_rtx,
+			   gen_rtx_raw_REG (SImode,
+					    CRIS_STACKADJ_REG)));
+  cris_expand_return (false);
+}
+
+/* Worker function for generating movem from mem for load_multiple.  */
+
+rtx
+cris_gen_movem_load (rtx osrc, rtx nregs_rtx, int nprefix)
+{
+  int nregs = INTVAL (nregs_rtx);
+  rtvec vec;
+  int eltno = 1;
+  int i;
+  rtx srcreg = XEXP (osrc, 0);
+  rtx src = osrc;
+  unsigned int regno = nregs - 1;
+  int regno_inc = -1;
+
+  if (GET_CODE (srcreg) == POST_INC)
+    srcreg = XEXP (srcreg, 0);
+
+  if (!REG_P (srcreg))
+    abort ();
+
+  /* Don't use movem for just one insn.  The insns are equivalent except
+     for the pipeline hazard; movem does not forward the loaded
+     registers so there's a three cycles penalty for use.  */
+  if (nregs == 1)
+    return gen_movsi (gen_rtx_REG (SImode, regno), osrc);
+
+  vec = rtvec_alloc (nprefix + nregs
+		     + (GET_CODE (XEXP (osrc, 0)) == POST_INC));
+  src = replace_equiv_address (osrc, srcreg);
+  RTVEC_ELT (vec, nprefix)
+    = gen_rtx_SET (VOIDmode, gen_rtx_REG (SImode, regno), src);
+  regno += regno_inc;
+
+  if (GET_CODE (XEXP (osrc, 0)) == POST_INC)
+    {
+      RTVEC_ELT (vec, nprefix + 1)
+	= gen_rtx_SET (VOIDmode, srcreg, plus_constant (srcreg, nregs * 4));
+      eltno++;
+    }
+
+  for (i = 1; i < nregs; i++, eltno++)
+    {
+      RTVEC_ELT (vec, nprefix + eltno)
+	= gen_rtx_SET (VOIDmode, gen_rtx_REG (SImode, regno),
+		       adjust_address_nv (src, SImode, i * 4));
+      regno += regno_inc;
+    }
+
+  return gen_rtx_PARALLEL (VOIDmode, vec);
+}
+
 /* Use from within code, from e.g. PRINT_OPERAND and
    PRINT_OPERAND_ADDRESS.  Macros used in output_addr_const need to emit
    different things depending on whether code operand or constant is
diff --git a/gcc/config/cris/cris.h b/gcc/config/cris/cris.h
index f1dd5da1d996..96c73037a486 100644
--- a/gcc/config/cris/cris.h
+++ b/gcc/config/cris/cris.h
@@ -1627,6 +1627,8 @@ struct cum_args {int regs;};
   {PLUS, UMIN}},					\
  {"cris_mem_op",					\
   {MEM}},						\
+ {"cris_load_multiple_op",				\
+  {PARALLEL}},						\
  {"cris_bdap_operand",					\
   {SUBREG, REG, LABEL_REF, SYMBOL_REF, MEM, CONST_INT,	\
    CONST_DOUBLE, CONST, SIGN_EXTEND}},			\
diff --git a/gcc/config/cris/cris.md b/gcc/config/cris/cris.md
index 5a794c5c2981..98f42ee80d98 100644
--- a/gcc/config/cris/cris.md
+++ b/gcc/config/cris/cris.md
@@ -58,6 +58,11 @@
 ;; UNSPEC Usage:
 ;; 0 PLT reference from call expansion: operand 0 is the address,
 ;;   the mode is VOIDmode.  Always wrapped in CONST.
+;; 1 Stack frame deallocation barrier.
+
+(define_constants
+  [(CRIS_UNSPEC_PLT 0)
+   (CRIS_UNSPEC_FRAME_DEALLOC 1)])
 
 
 ;; Register numbers.
@@ -1381,6 +1386,24 @@
    move %1,%0
    move %1,%0"
   [(set_attr "slottable" "yes,yes,yes,yes,yes,no,no,no,yes,yes,yes,no,yes,no")])
+
+;; Note that the order of the registers is the reverse of that of the
+;; standard pattern "load_multiple".
+(define_insn "*cris_load_multiple"
+  [(match_parallel 0 "cris_load_multiple_op"
+		   [(set (match_operand:SI 1 "register_operand" "=r,r")
+			 (match_operand:SI 2 "memory_operand" "Q,m"))])]
+  ""
+  "movem %O0,%o0"
+  [(set_attr "cc" "none")
+   (set_attr "slottable" "yes,no")
+   ;; Not true, but setting the length to 0 causes return sequences (ret
+   ;; movem) to have the cost they had when (return) included the movem
+   ;; and reduces the performance penalty taken for needing to emit an
+   ;; epilogue (in turn copied by bb-reorder) instead of return patterns.
+   ;; FIXME: temporary change until all insn lengths are correctly
+   ;; described.  FIXME: have better target control over bb-reorder.
+   (set_attr "length" "0")])
 
 
 ;; Sign- and zero-extend insns with standard names.
@@ -3467,69 +3490,37 @@
   "jump %0")
 
 ;; Return insn.  Used whenever the epilogue is very simple; if it is only
-;; a single ret or jump [sp+] or a contiguous sequence of movem:able saved
-;; registers.  No allocated stack space is allowed.
+;; a single ret or jump [sp+].  No allocated stack space or saved
+;; registers are allowed.
 ;; Note that for this pattern, although named, it is ok to check the
 ;; context of the insn in the test, not only compiler switches.
 
-(define_insn "return"
+(define_expand "return"
   [(return)]
   "cris_simple_epilogue ()"
-  "*
+  "cris_expand_return (cris_return_address_on_stack ()); DONE;")
+
+(define_insn "*return_expanded"
+  [(return)]
+  ""
 {
-  int i;
-
-  /* Just needs to hold a 'movem [sp+],rN'.  */
-  char rd[sizeof (\"movem [$sp+],$r99\")];
-
-  *rd = 0;
-
-  /* Start from the last call-saved register.  We know that we have a
-     simple epilogue, so we just have to find the last register in the
-     movem sequence.  */
-  for (i = 8; i >= 0; i--)
-    if (regs_ever_live[i]
-	|| (i == PIC_OFFSET_TABLE_REGNUM
-	    && current_function_uses_pic_offset_table))
-      break;
-
-  if (i >= 0)
-    sprintf (rd, \"movem [$sp+],$%s\", reg_names [i]);
-
-  if (regs_ever_live[CRIS_SRP_REGNUM]
-      || cris_return_address_on_stack ())
-    {
-      if (*rd)
-	output_asm_insn (rd, operands);
-      return \"jump [$sp+]\";
-    }
-
-  if (*rd)
-    {
-      output_asm_insn (\"reT\", operands);
-      output_asm_insn (rd, operands);
-      return \"\";
-    }
-
-  return \"ret%#\";
-}"
+  return cris_return_address_on_stack_for_return ()
+    ? "jump [$sp+]" : "ret%#";
+}
   [(set (attr "slottable")
-	(if_then_else
-	 (ne (symbol_ref
-	      "(regs_ever_live[CRIS_SRP_REGNUM]
-	        || cris_return_address_on_stack ())")
-	     (const_int 0))
-	 (const_string "no")	     ; If jump then not slottable.
-	 (if_then_else
-	  (ne (symbol_ref
-	       "(regs_ever_live[0]
-		 || (flag_pic != 0 && regs_ever_live[1])
-		 || (PIC_OFFSET_TABLE_REGNUM == 0
-		     && cris_cfun_uses_pic_table ()))")
-	      (const_int 0))
-	  (const_string "no") ; ret+movem [sp+],rx: slot already filled.
-	  (const_string "has_slot")))) ; If ret then need to fill a slot.
-   (set_attr "cc" "none")])
+ 	(if_then_else
+ 	 (ne (symbol_ref
+	      "(cris_return_address_on_stack_for_return ())")
+ 	     (const_int 0))
+ 	 (const_string "no")
+	 (const_string "has_slot")))])
+
+;; Note that the (return) from the expander itself is always the last
+;; insn in the epilogue.
+(define_expand "epilogue"
+  [(const_int 0)]
+  ""
+  "cris_expand_epilogue (); DONE;")
 
 ;; Conditional branches.
 
@@ -3929,7 +3920,8 @@
 			     gen_rtx_CONST
 			     (VOIDmode,
 			      gen_rtx_UNSPEC (VOIDmode,
-					      gen_rtvec (1, op0), 0)));
+					      gen_rtvec (1, op0),
+					      CRIS_UNSPEC_PLT)));
 	  else
 	    abort ();
 
@@ -3994,7 +3986,8 @@
 			     gen_rtx_CONST
 			     (VOIDmode,
 			      gen_rtx_UNSPEC (VOIDmode,
-					      gen_rtvec (1, op1), 0)));
+					      gen_rtvec (1, op1),
+					      CRIS_UNSPEC_PLT)));
 	  else
 	    abort ();
 
@@ -4040,6 +4033,20 @@
   "nop"
   [(set_attr "cc" "none")])
 
+;; We need to stop accesses to the stack after the memory is
+;; deallocated.  Unfortunately, reorg doesn't look at naked clobbers,
+;; e.g. (insn ... (clobber (mem:BLK (stack_pointer_rtx)))) and we don't
+;; want to use a naked (unspec_volatile) as that would stop any
+;; scheduling in the epilogue.  Hence we model it as a "real" insn that
+;; sets the memory in an unspecified manner.  FIXME: Unfortunately it
+;; still has the effect of an unspec_volatile.
+(define_insn "cris_frame_deallocated_barrier"
+  [(set (mem:BLK (reg:SI CRIS_SP_REGNUM))
+	(unspec:BLK [(const_int 0)] CRIS_UNSPEC_FRAME_DEALLOC))]
+  ""
+  ""
+  [(set_attr "length" "0")])
+
 ;; We expand on casesi so we can use "bound" and "add offset fetched from
 ;; a table to pc" (adds.w [pc+%0.w],pc).