re PR target/21981 ([4.0 only] __m64 return value should be returned in %mm0)

	PR target/21981
	* config/i386/i386.c (ix86_function_value_regno_p): Return true
	for FIRST_MMX_REG if TARGET_MMX.
	(ix86_return_in_memory): Return 1 for MMX/3dNow vectors. Delete
	wrong comment.
	(ix86_struct_value_rtx): Emit warning for MMX ABI violations.
	(ix86_value_regno): Return FIRST_MMX_REG for MMX vector modes.

From-SVN: r100832

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8b204a5983f81d91328874ac264cac76814f378a..7d6fc6aa4aa84c4ed0354c7ea21de98528994950 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2005-06-10  Uros Bizjak  <uros@kss-loka.si>
+
+       PR target/21981
+       * config/i386/i386.c (ix86_function_value_regno_p): Return true
+       for FIRST_MMX_REG if TARGET_MMX.
+       (ix86_return_in_memory): Return 1 for MMX/3dNow vectors. Delete
+       wrong comment.
+       (ix86_struct_value_rtx): Emit warning for MMX ABI violations.
+       (ix86_value_regno): Return FIRST_MMX_REG for MMX vector modes.
+
 2005-06-10  Daniel Berlin  <dberlin@dberlin.org>
 
        * lambda-code.c (replace_uses_equiv_to_x_with_y): Check step

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 8dd2d152dc77df2bf0006bd17fc45d91c73add6d..dfaac94dff053ee7bbfaf54fec466a2c56eef116 100644 (file)
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -3104,6 +3104,7 @@ ix86_function_value_regno_p (int regno)
     {
       return ((regno) == 0
              || ((regno) == FIRST_FLOAT_REG && TARGET_FLOAT_RETURNS_IN_80387)
+             || ((regno) == FIRST_MMX_REG && TARGET_MMX)
              || ((regno) == FIRST_SSE_REG && TARGET_SSE));
     }
   return ((regno) == 0 || (regno) == FIRST_FLOAT_REG
@@ -3159,10 +3160,10 @@ ix86_return_in_memory (tree type)
       if (size < 8)
        return 0;
 
-      /* MMX/3dNow values are returned on the stack, since we've
-        got to EMMS/FEMMS before returning.  */
+      /* MMX/3dNow values are returned in MM0,
+        except when it doesn't exits.  */
       if (size == 8)
-       return 1;
+       return (TARGET_MMX ? 0 : 1);
 
       /* SSE values are returned in XMM0, except when it doesn't exist.  */
       if (size == 16)
@@ -3191,18 +3192,32 @@ ix86_return_in_memory (tree type)
 static rtx
 ix86_struct_value_rtx (tree type, int incoming ATTRIBUTE_UNUSED)
 {
-  static bool warned;
+  static bool warnedsse, warnedmmx;
 
-  if (!TARGET_SSE && type && !warned)
+  if (type)
     {
       /* Look at the return type of the function, not the function type.  */
       enum machine_mode mode = TYPE_MODE (TREE_TYPE (type));
 
-      if (mode == TImode
-         || (VECTOR_MODE_P (mode) && GET_MODE_SIZE (mode) == 16))
+      if (!TARGET_SSE && !warnedsse)
        {
-         warned = true;
-         warning (0, "SSE vector return without SSE enabled changes the ABI");
+         if (mode == TImode
+             || (VECTOR_MODE_P (mode) && GET_MODE_SIZE (mode) == 16))
+           {
+             warnedsse = true;
+             warning (0, "SSE vector return without SSE enabled "
+                      "changes the ABI");
+           }
+       }
+
+      if (!TARGET_MMX && !warnedmmx)
+       {
+         if (VECTOR_MODE_P (mode) && GET_MODE_SIZE (mode) == 8)
+           {
+             warnedmmx = true;
+             warning (0, "MMX vector return without MMX enabled "
+                      "changes the ABI");
+           }
        }
     }
 
@@ -3244,6 +3259,11 @@ ix86_value_regno (enum machine_mode mode, tree func)
 {
   gcc_assert (!TARGET_64BIT);
 
+  /* 8-byte vector modes in %mm0. See ix86_return_in_memory for where
+     we prevent this case when mmx is not available.  */
+  if ((VECTOR_MODE_P (mode) && GET_MODE_SIZE (mode) == 8))
+    return FIRST_MMX_REG;
+
   /* 16-byte vector modes in %xmm0.  See ix86_return_in_memory for where
      we prevent this case when sse is not available.  */
   if (mode == TImode || (VECTOR_MODE_P (mode) && GET_MODE_SIZE (mode) == 16))