(movsf): Don't truncate if not register; clean up.

From-SVN: r7907

gcc/config/rs6000/rs6000.md

@@ -3794,18 +3794,18 @@
 
   if (GET_CODE (operands[0]) == MEM)
     {
-      operands[1] = force_reg (SFmode, operands[1]);
-      if (! TARGET_POWERPC)
-	if (reload_in_progress || reload_completed)
-	  emit_insn (gen_truncdfsf2 (operands[1],
-				     gen_rtx (SUBREG, DFmode, operands[1], 0)));
-	else
+      /* If operands[1] is a register, it may have double-precision data
+	 in it, so truncate it to single precision.  We need not do
+	 this for POWERPC.  */
+      if (! TARGET_POWERPC && GET_CODE (operands[1]) == REG)
 	{
-	    rtx newreg = gen_reg_rtx (SFmode);
+	  rtx newreg = reload_in_progress ? operands[1] : gen_reg_rtx (SFmode);
 	  emit_insn (gen_truncdfsf2 (newreg,
 				     gen_rtx (SUBREG, DFmode, operands[1], 0)));
 	  operands[1] = newreg;
 	}
+
+      operands[1] = force_reg (SFmode, operands[1]);
     }
 
   if (GET_CODE (operands[0]) == REG && REGNO (operands[0]) < 32)