mips.h (FRAME_GROWS_DOWNWARD, [...]): Define new macros.

	* config/mips/mips.h (FRAME_GROWS_DOWNWARD,
	MIPS_GP_SAVE_AREA_SIZE): Define new macros.
	(STARTING_FRAME_OFFSET): Return 0 if FRAME_GROWS_DOWNWARD.  Use
	MIPS_GP_SAVE_AREA_SIZE.
	* config/mips/mips.c (struct mips_frame_info): Update comment
	before arg_pointer_offset and hard_frame_pointer_offset.
	(mips_compute_frame_info): Update diagram before function: to
	correctly use stack_pointer_rtx for fp_sp_offset and gp_sp_offset, to
	indicate the position of frame_pointer_rtx with -fstack-protector and
	to show args_size.  Don't allocate cprestore area for leaf functions
	if FRAME_GROWS_DOWNWARD.  Use MIPS_GP_SAVE_AREA_SIZE to set
	cprestore_size.
	(mips_initial_elimination_offset): Update for FRAME_GROWS_DOWNWARD.

From-SVN: r147024

gcc/ChangeLog

+2009-04-30  Adam Nemet  <anemet@caviumnetworks.com>
+
+	* config/mips/mips.h (FRAME_GROWS_DOWNWARD,
+	MIPS_GP_SAVE_AREA_SIZE): Define new macros.
+	(STARTING_FRAME_OFFSET): Return 0 if FRAME_GROWS_DOWNWARD.  Use
+	MIPS_GP_SAVE_AREA_SIZE.
+	* config/mips/mips.c (struct mips_frame_info): Update comment
+	before arg_pointer_offset and hard_frame_pointer_offset.
+	(mips_compute_frame_info): Update diagram before function: to
+	correctly use stack_pointer_rtx for fp_sp_offset and gp_sp_offset, to
+	indicate the position of frame_pointer_rtx with -fstack-protector and
+	to show args_size.  Don't allocate cprestore area for leaf functions
+	if FRAME_GROWS_DOWNWARD.  Use MIPS_GP_SAVE_AREA_SIZE to set
+	cprestore_size.
+	(mips_initial_elimination_offset): Update for FRAME_GROWS_DOWNWARD.
+
 2009-04-30  Michael Matz  <matz@suse.de>
 
-        PR tree-optimization/39955
-        * config/rs6000/rs6000.c (rs6000_check_sdmode): Also check SSA_NAMEs.
+	PR tree-optimization/39955
+	* config/rs6000/rs6000.c (rs6000_check_sdmode): Also check SSA_NAMEs.
 
 2009-04-30  Dave Korn  <dave.korn.cygwin@gmail.com>
 

gcc/config/mips/mips.c

@@ -285,10 +285,10 @@ struct GTY(())  mips_frame_info {
   HOST_WIDE_INT acc_sp_offset;
   HOST_WIDE_INT cop0_sp_offset;
 
-  /* The offset of arg_pointer_rtx from frame_pointer_rtx.  */
+  /* The offset of arg_pointer_rtx from the bottom of the frame.  */
   HOST_WIDE_INT arg_pointer_offset;
 
-  /* The offset of hard_frame_pointer_rtx from frame_pointer_rtx.  */
+  /* The offset of hard_frame_pointer_rtx from the bottom of the frame.  */
   HOST_WIDE_INT hard_frame_pointer_offset;
 };
 
@@ -8673,16 +8673,16 @@ mips_save_reg_p (unsigned int regno)
 	|                               |       + UNITS_PER_WORD
 	|  accumulator save area        |
 	|                               |
-	+-------------------------------+ <-- frame_pointer_rtx + fp_sp_offset
+	+-------------------------------+ <-- stack_pointer_rtx + fp_sp_offset
 	|                               |       + UNITS_PER_HWFPVALUE
 	|  FPR save area                |
 	|                               |
-	+-------------------------------+ <-- frame_pointer_rtx + gp_sp_offset
+	+-------------------------------+ <-- stack_pointer_rtx + gp_sp_offset
 	|                               |       + UNITS_PER_WORD
 	|  GPR save area                |
 	|                               |
-	+-------------------------------+
-	|                               | \
+	+-------------------------------+ <-- frame_pointer_rtx with
+	|                               | \     -fstack-protector
 	|  local variables              |  | var_size
 	|                               | /
 	+-------------------------------+
@@ -8690,16 +8690,17 @@ mips_save_reg_p (unsigned int regno)
 	|  $gp save area                |  | cprestore_size
 	|                               | /
       P +-------------------------------+ <-- hard_frame_pointer_rtx for
-	|                               |       MIPS16 code
-	|  outgoing stack arguments     |
-	|                               |
-	+-------------------------------+
-	|                               |
-	|  caller-allocated save area   |
-	|  for register arguments       |
-	|                               |
+	|                               | \     MIPS16 code
+	|  outgoing stack arguments     |  |
+	|                               |  |
+	+-------------------------------+  | args_size
+	|                               |  |
+	|  caller-allocated save area   |  |
+	|  for register arguments       |  |
+	|                               | /
 	+-------------------------------+ <-- stack_pointer_rtx
-					      frame_pointer_rtx
+					      frame_pointer_rtx without
+					        -fstack-protector
 					      hard_frame_pointer_rtx for
 						non-MIPS16 code.
 
@@ -8744,11 +8745,11 @@ mips_compute_frame_info (void)
 
   cfun->machine->global_pointer = mips_global_pointer ();
 
-  /* The first STARTING_FRAME_OFFSET bytes contain the outgoing argument
-     area and the $gp save slot.  This area isn't needed in leaf functions,
-     but if the target-independent frame size is nonzero, we're committed
-     to allocating it anyway.  */
-  if (size == 0 && current_function_is_leaf)
+  /* The first two blocks contain the outgoing argument area and the $gp save
+     slot.  This area isn't needed in leaf functions, but if the
+     target-independent frame size is nonzero, we have already committed to
+     allocating these in STARTING_FRAME_OFFSET for !FRAME_GROWS_DOWNWARD.  */
+  if ((size == 0 || FRAME_GROWS_DOWNWARD) && current_function_is_leaf)
     {
       /* The MIPS 3.0 linker does not like functions that dynamically
 	 allocate the stack and have 0 for STACK_DYNAMIC_OFFSET, since it
@@ -8763,7 +8764,7 @@ mips_compute_frame_info (void)
   else
     {
       frame->args_size = crtl->outgoing_args_size;
-      frame->cprestore_size = STARTING_FRAME_OFFSET - frame->args_size;
+      frame->cprestore_size = MIPS_GP_SAVE_AREA_SIZE;
     }
   offset = frame->args_size + frame->cprestore_size;
 
@@ -8942,12 +8943,16 @@ mips_initial_elimination_offset (int from, int to)
 
   mips_compute_frame_info ();
 
-  /* Set OFFSET to the offset from the soft frame pointer, which is also
-     the offset from the end-of-prologue stack pointer.  */
+  /* Set OFFSET to the offset from the end-of-prologue stack pointer.  */
   switch (from)
     {
     case FRAME_POINTER_REGNUM:
-      offset = 0;
+      if (FRAME_GROWS_DOWNWARD)
+	offset = (cfun->machine->frame.args_size
+		  + cfun->machine->frame.cprestore_size
+		  + cfun->machine->frame.var_size);
+      else
+	offset = 0;
       break;
 
     case ARG_POINTER_REGNUM:

gcc/config/mips/mips.h

@@ -2081,12 +2081,20 @@ enum reg_class
 
 #define STACK_GROWS_DOWNWARD
 
-/* The offset of the first local variable from the beginning of the frame.
-   See mips_compute_frame_info for details about the frame layout.  */
+#define FRAME_GROWS_DOWNWARD flag_stack_protect
 
-#define STARTING_FRAME_OFFSET						\
-  (crtl->outgoing_args_size					\
-   + (TARGET_CALL_CLOBBERED_GP ? MIPS_STACK_ALIGN (UNITS_PER_WORD) : 0))
+/* Size of the area allocated in the frame to save the GP.  */
+
+#define MIPS_GP_SAVE_AREA_SIZE \
+  (TARGET_CALL_CLOBBERED_GP ? MIPS_STACK_ALIGN (UNITS_PER_WORD) : 0)
+
+/* The offset of the first local variable from the frame pointer.  See
+   mips_compute_frame_info for details about the frame layout.  */
+
+#define STARTING_FRAME_OFFSET				\
+  (FRAME_GROWS_DOWNWARD					\
+   ? 0							\
+   : crtl->outgoing_args_size + MIPS_GP_SAVE_AREA_SIZE)
 
 #define RETURN_ADDR_RTX mips_return_addr