(use_movqi, const_method): New functions.

(const_int_cost, output_move_const_into_data_reg): Likewise.
(singlemove_string): Call output_move_const_into_data_reg.

From-SVN: r8750

gcc/config/m68k/m68k.c

 /* Subroutines for insn-output.c for Motorola 68000 family.
-   Copyright (C) 1987, 1993, 1994 Free Software Foundation, Inc.
+   Copyright (C) 1987, 1993, 1994, 1995 Free Software Foundation, Inc.
 
 This file is part of GNU CC.
 
@@ -886,6 +886,116 @@ legitimize_pic_address (orig, mode, reg)
 }
 
 
+typedef enum { MOVL, SWAP, NEGW, NOTW, NOTB, MOVQ } CONST_METHOD;
+
+use_movq (i)
+     int i;
+{
+  return (i >= -128 && i <= 127);
+}
+
+CONST_METHOD
+const_method (constant)
+     rtx constant;
+{
+  int i;
+  unsigned u;
+
+  i = INTVAL (constant);
+  if (use_movq (i))
+    return MOVQ;
+  /* if -256 < N < 256 but N is not in range for a moveq
+     N^ff will be, so use moveq #N^ff, dreg; not.b dreg. */
+  if (use_movq (i ^ 0xff))
+    return NOTB;
+  /* Likewise, try with not.w */
+  if (use_movq (i ^ 0xffff))
+    return NOTW;
+  /* This is the only value where neg.w is usefull */
+  if (i == -65408)
+    return NEGW;
+  /* Try also with swap */
+  u = i;
+  if (use_movq ((u >> 16) | (u << 16)))
+    return SWAP;
+  /* Otherwise, use move.l */
+  return MOVL;
+}
+
+const_int_cost (constant)
+     rtx constant;
+{
+  switch (const_method (constant))
+    {
+      case MOVQ :
+      /* Constants between -128 and 127 are cheap due to moveq */
+	return 0;
+      case NOTB :
+      case NOTW :
+      case NEGW :
+      case SWAP :
+      /* Constants easily generated by moveq + not.b/not.w/neg.w/swap  */
+        return 1;
+      case MOVL :
+	return 2;
+      default :
+        abort ();
+    }
+}
+
+char *
+output_move_const_into_data_reg (operands)
+     rtx *operands;
+{
+  int i;
+
+  i = INTVAL (operands[1]);
+  switch (const_method (operands[1]))
+    {
+    case MOVQ :
+#if defined (MOTOROLA) && !defined (CRDS)
+      return "moveq%.l %1,%0";
+#else
+      return "moveq %1,%0";
+#endif
+    case NOTB :
+      operands[1] = gen_rtx (CONST_INT, VOIDmode, i ^ 0xff);
+#if defined (MOTOROLA) && !defined (CRDS)
+      return "moveq%.l %1,%0\n\tnot%.b %0";
+#else
+      return "moveq %1,%0\n\tnot%.b %0";
+#endif	 
+    case NOTW :
+      operands[1] = gen_rtx (CONST_INT, VOIDmode, i ^ 0xffff);
+#if defined (MOTOROLA) && !defined (CRDS)
+      return "moveq%.l %1,%0\n\tnot%.w %0";
+#else
+      return "moveq %1,%0\n\tnot%.w %0";
+#endif	 
+    case NEGW :
+#if defined (MOTOROLA) && !defined (CRDS)
+      return "moveq%.l %#-128,%0\n\tneg%.w %0";
+#else
+      return "moveq %#-128,%0\n\tneg%.w %0";
+#endif	 
+    case SWAP :
+      {
+	unsigned u = i;
+
+	operands[1] = gen_rtx (CONST_INT, VOIDmode, (u << 16) | (u >> 16));
+#if defined (MOTOROLA) && !defined (CRDS)
+	return "moveq%.l %1,%0\n\tswap %0";
+#else
+	return "moveq %1,%0\n\tswap %0";
+#endif	 
+      }
+    case MOVL :
+	return "move%.l %1,%0";
+    default :
+	abort ();
+    }
+}
+
 /* Return the best assembler insn template
    for moving operands[1] into operands[0] as a fullword.  */
 
@@ -898,16 +1008,8 @@ singlemove_string (operands)
     return "fpmoves %1,%0";
 #endif
   if (DATA_REG_P (operands[0])
-      && GET_CODE (operands[1]) == CONST_INT
-      && INTVAL (operands[1]) < 128
-      && INTVAL (operands[1]) >= -128)
-    {
-#if defined (MOTOROLA) && !defined (CRDS)
-      return "moveq%.l %1,%0";
-#else
-      return "moveq %1,%0";
-#endif
-    }
+      && GET_CODE (operands[1]) == CONST_INT)
+      return output_move_const_into_data_reg (operands);
   if (operands[1] != const0_rtx)
     return "move%.l %1,%0";
   if (! ADDRESS_REG_P (operands[0]))