--- gcc/config/i860/i860.c	2018/04/24 18:10:24	1.1
+++ gcc/config/i860/i860.c	2018/04/24 18:15:03	1.1.1.2
@@ -572,6 +572,8 @@ output_move_double (operands)
   enum { REGOP, OFFSOP, MEMOP, PUSHOP, POPOP, CNSTOP, RNDOP } optype0, optype1;
   rtx latehalf[2];
   rtx addreg0 = 0, addreg1 = 0;
+  int highest_first = 0;
+  int no_addreg1_decrement = 0;
 
   /* First classify both operands.  */
 
@@ -680,15 +682,40 @@ output_move_double (operands)
   else if (optype0 == REGOP && optype1 != REGOP
 	   && reg_overlap_mentioned_p (operands[0], operands[1]))
     {
-      /* Do the late half first.  */
-      output_asm_insn (singlemove_string (latehalf), latehalf);
-      /* Then clobber.  */
-      return singlemove_string (operands);
+      /* If both halves of dest are used in the src memory address,
+	 add the two regs and put them in the low reg (operands[0]).
+	 Then it works to load latehalf first.  */
+      if (reg_mentioned_p (operands[0], XEXP (operands[1], 0))
+	  && reg_mentioned_p (latehalf[0], XEXP (operands[1], 0)))
+	{
+	  rtx xops[2];
+	  xops[0] = latehalf[0];
+	  xops[1] = operands[0];
+	  output_asm_insn ("adds %1,%0,%1", xops);
+	  operands[1] = gen_rtx (MEM, DImode, operands[0]);
+	  latehalf[1] = adj_offsettable_operand (operands[1], 4);
+	  addreg1 = 0;
+	  highest_first = 1;
+	}
+      /* Only one register in the dest is used in the src memory address,
+	 and this is the first register of the dest, so we want to do
+	 the late half first here also.  */
+      else if (! reg_mentioned_p (latehalf[0], XEXP (operands[1], 0)))
+	highest_first = 1;
+      /* Only one register in the dest is used in the src memory address,
+	 and this is the second register of the dest, so we want to do
+	 the late half last.  If addreg1 is set, and addreg1 is the same
+	 register as latehalf, then we must suppress the trailing decrement,
+	 because it would clobber the value just loaded.  */
+      else if (addreg1 && reg_mentioned_p (addreg1, latehalf[0]))
+	no_addreg1_decrement = 1;
     }
 
-  /* Normal case: do the two words, low-numbered first.  */
+  /* Normal case: do the two words, low-numbered first.
+     Overlap case (highest_first set): do high-numbered word first.  */
 
-  output_asm_insn (singlemove_string (operands), operands);
+  if (! highest_first)
+    output_asm_insn (singlemove_string (operands), operands);
 
   CC_STATUS_PARTIAL_INIT;
   /* Make any unoffsettable addresses point at high-numbered word.  */
@@ -703,9 +730,12 @@ output_move_double (operands)
   /* Undo the adds we just did.  */
   if (addreg0)
     output_asm_insn ("adds -0x4,%0,%0", &addreg0);
-  if (addreg1)
+  if (addreg1 && !no_addreg1_decrement)
     output_asm_insn ("adds -0x4,%0,%0", &addreg1);
 
+  if (highest_first)
+    output_asm_insn (singlemove_string (operands), operands);
+
   return "";
 }