m68k.md (adddi3, subdi3): Properly negate the DImode constant.

	* config/m68k/m68k.md (adddi3, subdi3): Properly negate the DImode
	constant.

From-SVN: r19607

gcc/ChangeLog

+Thu May  7 10:55:59 1998  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>
+
+	* config/m68k/m68k.md (adddi3, subdi3): Properly negate the DImode
+	constant. 
+
 Wed May  6 22:32:37 CDT 1998 Robert Lipe  <robertl@dgii.com>
 
 	* Makefile.in (dwarfout.o) Add toplev.h dependency.

gcc/config/m68k/m68k.md

@@ -2166,7 +2166,11 @@
 	  else
 	    operands[1] = adj_offsettable_operand (operands[2], 4);
 	  xoperands[0] = operands[3];
-	  xoperands[1] = operands[2];
+	  if (GET_CODE (operands[1]) == CONST_INT
+	      && INTVAL (operands[1]) >= -8 && INTVAL (operands[1]) < 0)
+	    xoperands[1] = GEN_INT (-INTVAL (operands[2]) - 1);
+	  else
+	    xoperands[1] = operands[2];
 	  output_asm_insn (output_move_simode (xoperands), xoperands);
 	  if (GET_CODE (operands[1]) == CONST_INT)
 	    {
@@ -2182,9 +2186,9 @@
 		{
 		  operands[1] = GEN_INT (-INTVAL (operands[1]));
 #ifdef NO_ADDSUB_Q
-		  return \"sub%.l %1,%R0\;addx%.l %3,%0\";
+		  return \"sub%.l %1,%R0\;subx%.l %3,%0\";
 #else
-		  return \"subq%.l %1,%R0\;addx%.l %3,%0\";
+		  return \"subq%.l %1,%R0\;subx%.l %3,%0\";
 #endif
 		}
 	    }
@@ -2719,7 +2723,11 @@
 	  else
 	    operands[1] = adj_offsettable_operand (operands[2], 4);
 	  xoperands[0] = operands[3];
-	  xoperands[1] = operands[2];
+	  if (GET_CODE (operands[1]) == CONST_INT
+	      && INTVAL (operands[1]) >= -8 && INTVAL (operands[1]) < 0)
+	    xoperands[1] = GEN_INT (-INTVAL (operands[2]) - 1);
+	  else
+	    xoperands[1] = operands[2];
 	  output_asm_insn (output_move_simode (xoperands), xoperands);
 	  if (GET_CODE (operands[1]) == CONST_INT)
 	    {
@@ -2735,9 +2743,9 @@
 		{
 		  operands[1] = GEN_INT (-INTVAL (operands[1]));
 #ifdef NO_ADDSUB_Q
-		  return \"add%.l %1,%R0\;subx%.l %3,%0\";
+		  return \"add%.l %1,%R0\;addx%.l %3,%0\";
 #else
-		  return \"addq%.l %1,%R0\;subx%.l %3,%0\";
+		  return \"addq%.l %1,%R0\;addx%.l %3,%0\";
 #endif
 		}
 	    }