tm.texi (TARGET_PROMOTE_FUNCTION_MODE): Add documentation for for_return == 2.

2009-08-12  Paolo Bonzini  <bonzini@gnu.org>

	* doc/tm.texi (TARGET_PROMOTE_FUNCTION_MODE): Add documentation
	for for_return == 2.
	* function.c (assign_parm_setup_reg): Use for_return == 2, improve
	comments.
	* calls.c (expand_call): Fix typo.
	* explow.c (promote_decl_mode): Use for_return == 2 for RESULT_DECL
	and PARM_DECL.
	* stmt.c (expand_value_return): Use promote_function_mode to copy out
	of pseudo.
	* targhooks.c (default_promote_function_mode): Handle for_return == 2.
	* config/cris/cris.c (cris_promote_function_mode): Likewise.
	* config/mmix/mmix.c (mmix_promote_function_mode): Likewise.
	* config/pa/pa.c (pa_promote_function_mode): Likewise.

From-SVN: r150700

gcc/ChangeLog

@@ -1,3 +1,19 @@
+2009-08-12  Paolo Bonzini  <bonzini@gnu.org>
+
+	* doc/tm.texi (TARGET_PROMOTE_FUNCTION_MODE): Add documentation
+	for for_return == 2.
+	* function.c (assign_parm_setup_reg): Use for_return == 2, improve
+	comments.
+	* calls.c (expand_call): Fix typo.
+	* explow.c (promote_decl_mode): Use for_return == 2 for RESULT_DECL
+	and PARM_DECL.
+	* stmt.c (expand_value_return): Use promote_function_mode to copy out
+	of pseudo.
+	* targhooks.c (default_promote_function_mode): Handle for_return == 2.
+	* config/cris/cris.c (cris_promote_function_mode): Likewise.
+	* config/mmix/mmix.c (mmix_promote_function_mode): Likewise.
+	* config/pa/pa.c (pa_promote_function_mode): Likewise.
+
 2009-08-11  Andrew Haley  <aph@redhat.com>
 
 	* config/arm/arm.c (arm_init_libfuncs): Add __sync_synchronize.

gcc/calls.c

@@ -2353,9 +2353,9 @@ expand_call (tree exp, rtx target, int ignore)
 				 &caller_unsignedp,
 				 TREE_TYPE (current_function_decl), 1);
       callee_promoted_mode
-	= promote_function_mode (TREE_TYPE (caller_res), callee_mode,
+	= promote_function_mode (TREE_TYPE (funtype), callee_mode,
 				 &callee_unsignedp,
-				 TREE_TYPE (funtype), 1);
+				 funtype, 1);
       if (caller_mode != VOIDmode
 	  && (caller_promoted_mode != callee_promoted_mode
 	      || ((caller_mode != caller_promoted_mode

gcc/config/cris/cris.c

@@ -3771,7 +3771,7 @@ cris_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
   /* Defining PROMOTE_FUNCTION_RETURN in gcc-2.7.2 uncovered bug 981110 (even
      when modifying FUNCTION_VALUE to return the promoted mode).  Maybe
      pointless as of now, but let's keep the old behavior.  */
-  if (for_return)
+  if (for_return == 1)
     return mode;
   return CRIS_PROMOTED_MODE (mode, *punsignedp, type);
 } 

gcc/config/mmix/mmix.c

@@ -2701,7 +2701,7 @@ mmix_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
 {
   /* Apparently not doing TRT if int < register-size.  FIXME: Perhaps
      FUNCTION_VALUE and LIBCALL_VALUE needs tweaking as some ports say.  */
-  if (for_return)
+  if (for_return == 1)
     return mode;
 
   /* Promotion of modes currently generates slow code, extending before

gcc/config/pa/pa.c

@@ -9199,7 +9199,7 @@ pa_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
                           const_tree fntype ATTRIBUTE_UNUSED,
                           int for_return)
 {
-  if (!for_return)
+  if (for_return == 0)
     return mode;
   return promote_mode (type, mode, punsignedp);
 }

gcc/doc/tm.texi

@@ -1046,13 +1046,17 @@ and possibly change @code{*@var{punsignedp}} if the promotion should
 change signedness.  This function is called only for scalar @emph{or
 pointer} types.
 
+@var{for_return} allows to distinguish the promotion of arguments and
+return values.  If it is @code{1}, a return value is being promoted and
+@code{TARGET_FUNCTION_VALUE} must perform the same promotions done here.
+If it is @code{2}, the returned mode should be that of the register in
+which an incoming parameter is copied, or the outgoing result is computed;
+then the hook should return the same mode as @code{promote_mode}, though
+the signedness may be different.
+
 The default is to not promote arguments and return values.  You can
 also define the hook to @code{default_promote_function_mode_always_promote}
 if you would like to apply the same rules given by @code{PROMOTE_MODE}.
-
-@var{for_return} allows to distinguish the promotion of arguments and
-return values.  If this target hook promotes return values,
-@code{TARGET_FUNCTION_VALUE} must perform the same promotions done here.
 @end deftypefn
 
 @defmac PARM_BOUNDARY

gcc/explow.c

@@ -825,12 +825,10 @@ promote_decl_mode (const_tree decl, int *punsignedp)
   enum machine_mode mode = DECL_MODE (decl);
   enum machine_mode pmode;
 
-  if (TREE_CODE (decl) == RESULT_DECL)
+  if (TREE_CODE (decl) == RESULT_DECL
+      || TREE_CODE (decl) == PARM_DECL)
     pmode = promote_function_mode (type, mode, &unsignedp,
-                                   TREE_TYPE (current_function_decl), 1);
+                                   TREE_TYPE (current_function_decl), 2);
-  else if (TREE_CODE (decl) == PARM_DECL)
-    pmode = promote_function_mode (type, mode, &unsignedp,
-                                   TREE_TYPE (current_function_decl), 0);
   else
     pmode = promote_mode (type, mode, &unsignedp);
 

gcc/function.c

@@ -2770,13 +2770,11 @@ assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
   bool did_conversion = false;
 
   /* Store the parm in a pseudoregister during the function, but we may
-     need to do it in a wider mode.  */
+     need to do it in a wider mode.  Using 2 here makes the result
-
+     consistent with promote_decl_mode and thus expand_expr_real_1.  */
-  /* This is not really promoting for a call.  However we need to be
-     consistent with assign_parm_find_data_types and expand_expr_real_1.  */
   promoted_nominal_mode
     = promote_function_mode (data->nominal_type, data->nominal_mode, &unsignedp,
-			     TREE_TYPE (current_function_decl), 0);
+			     TREE_TYPE (current_function_decl), 2);
 
   parmreg = gen_reg_rtx (promoted_nominal_mode);
 
@@ -2796,7 +2794,8 @@ assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
 
   assign_parm_remove_parallels (data);
 
-  /* Copy the value into the register.  */
+  /* Copy the value into the register, thus bridging between
+     assign_parm_find_data_types and expand_expr_real_1.  */
   if (data->nominal_mode != data->passed_mode
       || promoted_nominal_mode != data->promoted_mode)
     {

gcc/stmt.c

@@ -1511,25 +1511,24 @@ expand_naked_return (void)
 static void
 expand_value_return (rtx val)
 {
-  /* Copy the value to the return location
+  /* Copy the value to the return location unless it's already there.  */
-     unless it's already there.  */
 
   tree decl = DECL_RESULT (current_function_decl);
   rtx return_reg = DECL_RTL (decl);
   if (return_reg != val)
     {
-      int unsignedp;
+      tree funtype = TREE_TYPE (current_function_decl);
+      tree type = TREE_TYPE (decl);
+      int unsignedp = TYPE_UNSIGNED (type);
       enum machine_mode old_mode = DECL_MODE (decl);
-      enum machine_mode mode = promote_decl_mode (decl, &unsignedp);
+      enum machine_mode mode = promote_function_mode (type, old_mode,
+						      &unsignedp, funtype, 1);
 
       if (mode != old_mode)
 	val = convert_modes (mode, old_mode, val, unsignedp);
 
       if (GET_CODE (return_reg) == PARALLEL)
-	{
+	emit_group_load (return_reg, val, type, int_size_in_bytes (type));
-          tree type = TREE_TYPE (decl);
-	  emit_group_load (return_reg, val, type, int_size_in_bytes (type));
-	}
       else
 	emit_move_insn (return_reg, val);
     }

gcc/targhooks.c

@@ -119,6 +119,8 @@ default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
 			       const_tree funtype ATTRIBUTE_UNUSED,
 			       int for_return ATTRIBUTE_UNUSED)
 {
+  if (for_return == 2)
+    return promote_mode (type, mode, punsignedp);
   return mode;
 }