i386.i386.c (ix86_return_in_memory): Reformat.

        * config/i386.i386.c (ix86_return_in_memory): Reformat.  Return true
        for 16-byte vector modes if sse not enabled; warn for abi change.
        (ix86_value_regno): Only return xmm0 for 16-byte vector types.
        * g++.dg/eh/simd-2.C: Add -w for x86.

From-SVN: r70771

4 files changed, 64 insertions, 19 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 42d313f..440fcdc 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2003-08-24  Richard Henderson  <rth@redhat.com>
+
+	* config/i386.i386.c (ix86_return_in_memory): Reformat.  Return true
+	for 16-byte vector modes if sse not enabled; warn for abi change.
+	(ix86_value_regno): Only return xmm0 for 16-byte vector types.
+
 2003-08-24  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* rtlanal.c (may_trap_p): Simplify an integer comparison.
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 1609b74..4984fc4 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -2691,29 +2691,59 @@ ix86_function_value (tree valtype)
 int
 ix86_return_in_memory (tree type)
 {
-  int needed_intregs, needed_sseregs;
+  int needed_intregs, needed_sseregs, size;
+  enum machine_mode mode = TYPE_MODE (type);
+
   if (TARGET_64BIT)
+    return !examine_argument (mode, type, 1, &needed_intregs, &needed_sseregs);
+
+  if (mode == BLKmode)
+    return 1;
+
+  size = int_size_in_bytes (type);
+
+  if (MS_AGGREGATE_RETURN && AGGREGATE_TYPE_P (type) && size <= 8)
+    return 0;
+
+  if (VECTOR_MODE_P (mode) || mode == TImode)
     {
-      return !examine_argument (TYPE_MODE (type), type, 1,
-				&needed_intregs, &needed_sseregs);
-    }
-  else
-    {
-      if (TYPE_MODE (type) == BLKmode)
-	return 1;
-      else if (MS_AGGREGATE_RETURN
-	       && AGGREGATE_TYPE_P (type)
-	       && int_size_in_bytes(type) <= 8)
+      /* User-created vectors small enough to fit in EAX.  */
+      if (size < 8)
 	return 0;
-      else if ((VECTOR_MODE_P (TYPE_MODE (type))
-	        && int_size_in_bytes (type) == 8)
-	       || (int_size_in_bytes (type) > 12
-		   && TYPE_MODE (type) != TImode
-		   && TYPE_MODE (type) != TFmode
-		   && !VECTOR_MODE_P (TYPE_MODE (type))))
+
+      /* MMX/3dNow values are returned on the stack, since we've
+	 got to EMMS/FEMMS before returning.  */
+      if (size == 8)
 	return 1;
-      return 0;
+
+      /* SSE values are returned in XMM0.  */
+      /* ??? Except when it doesn't exist?  We have a choice of
+	 either (1) being abi incompatible with a -march switch,
+	 or (2) generating an error here.  Given no good solution,
+	 I think the safest thing is one warning.  The user won't
+	 be able to use -Werror, but...  */
+      if (size == 16)
+	{
+	  static bool warned;
+
+	  if (TARGET_SSE)
+	    return 0;
+
+	  if (!warned)
+	    {
+	      warned = true;
+	      warning ("SSE vector return without SSE enabled "
+		       "changes the ABI");
+	    }
+	  return 1;
+	}
     }
+
+  if (mode == TFmode)
+    return 0;
+  if (size > 12)
+    return 1;
+  return 0;
 }
 
 /* Define how to find the value returned by a library function
@@ -2746,10 +2776,14 @@ ix86_libcall_value (enum machine_mode mode)
 static int
 ix86_value_regno (enum machine_mode mode)
 {
+  /* Floating point return values in %st(0).  */
   if (GET_MODE_CLASS (mode) == MODE_FLOAT && TARGET_FLOAT_RETURNS_IN_80387)
     return FIRST_FLOAT_REG;
-  if (mode == TImode || VECTOR_MODE_P (mode))
+  /* 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))
     return FIRST_SSE_REG;
+  /* Everything else in %eax.  */
   return 0;
 }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index bfcab55..5ed3354 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2003-08-24  Richard Henderson  <rth@redhat.com>
+
+	* g++.dg/eh/simd-2.C: Add -w for x86.
+
 2003-08-23  Jakub Jelinek  <jakub@redhat.com>
 
 	* gcc.dg/20030815-1.c: New test.
diff --git a/gcc/testsuite/g++.dg/eh/simd-2.C b/gcc/testsuite/g++.dg/eh/simd-2.C
index e6f1f7b..39f8dc8 100644
--- a/gcc/testsuite/g++.dg/eh/simd-2.C
+++ b/gcc/testsuite/g++.dg/eh/simd-2.C
@@ -1,6 +1,7 @@
 // Test EH when V4SI SIMD registers are involved.
 // Contributed by Aldy Hernandez (aldy@quesejoda.com).
 // { dg-options "-O" }
+// { dg-options "-O -w" { target i?86-*-* } }
 // { dg-do run }
 
 typedef int __attribute__((mode(V4SI))) vecint;