m68k.md (beq0_di): Generate correct (and more efficient) code when...

        * m68k.md (beq0_di): Generate correct (and more efficient) code when
        the clobbered operand overlaps with an input.
        (bne0_di): Similarly.

From-SVN: r22082

gcc/ChangeLog

 Sat Aug 29 12:39:56 1998  Jeffrey A Law  (law@cygnus.com)
 
+        * m68k.md (beq0_di): Generate correct (and more efficient) code when
+        the clobbered operand overlaps with an input.
+        (bne0_di): Similarly.
+
 	* Makefile.in (INSTALL): Remove "--no-header" argument.
 
         * NEWS: Various updates.

gcc/config/m68k/m68k.md

@@ -5958,6 +5958,25 @@
     operands[3] = adj_offsettable_operand (operands[0], 4);
   if (! ADDRESS_REG_P (operands[0]))
     {
+      if (reg_overlap_mentioned_p (operands[2], operands[0]))
+	{
+	  if (reg_overlap_mentioned_p (operands[2], operands[3]))
+	    {
+#ifdef MOTOROLA
+	      return \"or%.l %0,%2\;jbeq %l1\";
+#else
+	      return \"or%.l %0,%2\;jeq %l1\";
+#endif
+	    }
+	  else
+	    {
+#ifdef MOTOROLA
+	      return \"or%.l %3,%2\;jbeq %l1\";
+#else
+	      return \"or%.l %3,%2\;jeq %l1\";
+#endif
+	    }
+	}
 #ifdef MOTOROLA
       return \"move%.l %0,%2\;or%.l %3,%2\;jbeq %l1\";
 #else
@@ -6019,6 +6038,25 @@
     operands[3] = adj_offsettable_operand (operands[0], 4);
   if (!ADDRESS_REG_P (operands[0]))
     {
+      if (reg_overlap_mentioned_p (operands[2], operands[0]))
+	{
+	  if (reg_overlap_mentioned_p (operands[2], operands[3]))
+	    {
+#ifdef MOTOROLA
+	      return \"or%.l %0,%2\;jbne %l1\";
+#else
+	      return \"or%.l %0,%2\;jne %l1\";
+#endif
+	    }
+	  else
+	    {
+#ifdef MOTOROLA
+	      return \"or%.l %3,%2\;jbne %l1\";
+#else
+	      return \"or%.l %3,%2\;jne %l1\";
+#endif
+	    }
+	}
 #ifdef MOTOROLA
       return \"move%.l %0,%2\;or%.l %3,%2\;jbne %l1\";
 #else