[PATCH, i386]: A couple of cleanups in i386.c

[Uros Bizjak]

No functional changes.

2015-06-17  Uros Bizjak  <ubizjak@gmail.com>

    * config/i386/i386.c (ix86_function_arg): Nest TARGET_64BIT code.
    (ix86_function_arg_advance): Ditto.
    (ix86_pass_by_reference): Ditto.  Rewrite MS_ABI part.

Tested on x86_64-linux-gnu {,-m32} and committed to mainline SVN.

Uros.
-------------- next part --------------
Index: config/i386/i386.c
===================================================================
--- config/i386/i386.c	(revision 224561)
+++ config/i386/i386.c	(working copy)
@@ -7659,10 +7659,15 @@ ix86_function_arg_advance (cumulative_args_t cum_v
       cum->force_bnd_pass = 0;
     }
 
-  if (TARGET_64BIT && (cum ? cum->call_abi : ix86_abi) == MS_ABI)
-    nregs = function_arg_advance_ms_64 (cum, bytes, words);
-  else if (TARGET_64BIT)
-    nregs = function_arg_advance_64 (cum, mode, type, words, named);
+  if (TARGET_64BIT)
+    {
+      enum calling_abi call_abi = cum ? cum->call_abi : ix86_abi;
+
+      if (call_abi == MS_ABI)
+	nregs = function_arg_advance_ms_64 (cum, bytes, words);
+      else
+	nregs = function_arg_advance_64 (cum, mode, type, words, named);
+    }
   else
     nregs = function_arg_advance_32 (cum, mode, type, bytes, words);
 
@@ -7949,10 +7954,15 @@ ix86_function_arg (cumulative_args_t cum_v, machin
   if (type && TREE_CODE (type) == VECTOR_TYPE)
     mode = type_natural_mode (type, cum, false);
 
-  if (TARGET_64BIT && (cum ? cum->call_abi : ix86_abi) == MS_ABI)
-    arg = function_arg_ms_64 (cum, mode, omode, named, bytes);
-  else if (TARGET_64BIT)
-    arg = function_arg_64 (cum, mode, omode, type, named);
+  if (TARGET_64BIT)
+    {
+      enum calling_abi call_abi = cum ? cum->call_abi : ix86_abi;
+
+      if (call_abi == MS_ABI)
+	arg = function_arg_ms_64 (cum, mode, omode, named, bytes);
+      else
+	arg = function_arg_64 (cum, mode, omode, type, named);
+    }
   else
     arg = function_arg_32 (cum, mode, omode, type, bytes, words);
 
@@ -7976,36 +7986,37 @@ ix86_pass_by_reference (cumulative_args_t cum_v, m
       || POINTER_BOUNDS_MODE_P (mode))
     return false;
 
-  /* See Windows x64 Software Convention.  */
-  if (TARGET_64BIT && (cum ? cum->call_abi : ix86_abi) == MS_ABI)
+  if (TARGET_64BIT)
     {
-      int msize = (int) GET_MODE_SIZE (mode);
-      if (type)
+      enum calling_abi call_abi = cum ? cum->call_abi : ix86_abi;
+
+      /* See Windows x64 Software Convention.  */
+      if (call_abi == MS_ABI)
 	{
-	  /* Arrays are passed by reference.  */
-	  if (TREE_CODE (type) == ARRAY_TYPE)
-	    return true;
+	  HOST_WIDE_INT msize = GET_MODE_SIZE (mode);
 
-	  if (AGGREGATE_TYPE_P (type))
+	  if (type)
 	    {
-	      /* Structs/unions of sizes other than 8, 16, 32, or 64 bits
-	         are passed by reference.  */
-	      msize = int_size_in_bytes (type);
+	      /* Arrays are passed by reference.  */
+	      if (TREE_CODE (type) == ARRAY_TYPE)
+		return true;
+
+	      if (RECORD_OR_UNION_TYPE_P (type))
+		{
+		  /* Structs/unions of sizes other than 8, 16, 32, or 64 bits
+		     are passed by reference.  */
+		  msize = int_size_in_bytes (type);
+		}
 	    }
+
+	  /* __m128 is passed by reference.  */
+	  return msize != 1 && msize != 2 && msize != 4 && msize != 8;
 	}
-
-      /* __m128 is passed by reference.  */
-      switch (msize) {
-      case 1: case 2: case 4: case 8:
-        break;
-      default:
-        return true;
-      }
+      else if (type && int_size_in_bytes (type) == -1)
+	return true;
     }
-  else if (TARGET_64BIT && type && int_size_in_bytes (type) == -1)
-    return 1;
 
-  return 0;
+  return false;
 }
 
 /* Return true when TYPE should be 128bit aligned for 32bit argument