Promote pointer function arguments and return values to Pmode.

2011-07-21  H.J. Lu  <hongjiu.lu@intel.com>

	* config/i386/i386.c (function_value_64): Always return pointers
	in Pmode.
	(ix86_promote_function_mode): New.
	(TARGET_PROMOTE_FUNCTION_MODE): Likewise.

From-SVN: r176593

gcc/ChangeLog

+2011-07-21  H.J. Lu  <hongjiu.lu@intel.com>
+
+	* config/i386/i386.c (function_value_64): Always return pointers
+	in Pmode.
+	(ix86_promote_function_mode): New.
+	(TARGET_PROMOTE_FUNCTION_MODE): Likewise.
+
 2011-07-21  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 
 	PR tree-optimization/49749

gcc/config/i386/i386.c

@@ -7078,6 +7078,11 @@ function_value_64 (enum machine_mode orig_mode, enum machine_mode mode,
 	  return gen_rtx_REG (mode, AX_REG);
 	}
     }
+  else if (POINTER_TYPE_P (valtype))
+    {
+      /* Pointers are always returned in Pmode. */
+      mode = Pmode;
+    }
 
   ret = construct_container (mode, orig_mode, valtype, 1,
 			     X86_64_REGPARM_MAX, X86_64_SSE_REGPARM_MAX,
@@ -7147,6 +7152,22 @@ ix86_function_value (const_tree valtype, const_tree fntype_or_decl,
   return ix86_function_value_1 (valtype, fntype_or_decl, orig_mode, mode);
 }
 
+/* Pointer function arguments and return values are promoted to Pmode.  */
+
+static enum machine_mode
+ix86_promote_function_mode (const_tree type, enum machine_mode mode,
+			    int *punsignedp, const_tree fntype,
+			    int for_return)
+{
+  if (type != NULL_TREE && POINTER_TYPE_P (type))
+    {
+      *punsignedp = POINTERS_EXTEND_UNSIGNED;
+      return Pmode;
+    }
+  return default_promote_function_mode (type, mode, punsignedp, fntype,
+					for_return);
+}
+
 rtx
 ix86_libcall_value (enum machine_mode mode)
 {
@@ -34970,6 +34991,9 @@ ix86_autovectorize_vector_sizes (void)
 #undef TARGET_FUNCTION_VALUE_REGNO_P
 #define TARGET_FUNCTION_VALUE_REGNO_P ix86_function_value_regno_p
 
+#undef TARGET_PROMOTE_FUNCTION_MODE
+#define TARGET_PROMOTE_FUNCTION_MODE ix86_promote_function_mode
+
 #undef TARGET_SECONDARY_RELOAD
 #define TARGET_SECONDARY_RELOAD ix86_secondary_reload