--- a/src/newgrf_spritegroup.cpp	Sat Sep 22 18:53:32 2007 +0000
+++ b/src/newgrf_spritegroup.cpp	Sat Sep 22 20:29:17 2007 +0000
@@ -106,6 +106,21 @@
 }
 
 
+/**
+ * Rotate val rot times to the right
+ * @param val the value to rotate
+ * @param rot the amount of times to rotate
+ * @return the rotated value
+ */
+static uint32 RotateRight(uint32 val, uint32 rot)
+{
+	/* Do not rotate more than necessary */
+	rot %= 32;
+
+	return (val >> rot) | (val << (32 - rot));
+}
+
+
 /* Evaluate an adjustment for a variable of the given size.
 * U is the unsigned type and S is the signed type to use. */
 template <typename U, typename S>
@@ -140,6 +155,9 @@
 		case DSGA_OP_STO:  _temp_store.Store(value, last_value); return last_value;
 		case DSGA_OP_RST:  return value;
 		case DSGA_OP_STOP: if (object->psa != NULL) object->psa->Store(value, last_value); return last_value;
+		case DSGA_OP_ROR:  return RotateRight(last_value, value);
+		case DSGA_OP_SCMP: return ((S)last_value == (S)value) ? 1 : ((S)last_value < (S)value ? 0 : 2);
+		case DSGA_OP_UCMP: return ((U)last_value == (U)value) ? 1 : ((U)last_value < (U)value ? 0 : 2);
 		default:           return value;
 	}
 }

--- a/src/newgrf_spritegroup.h	Sat Sep 22 18:53:32 2007 +0000
+++ b/src/newgrf_spritegroup.h	Sat Sep 22 20:29:17 2007 +0000
@@ -77,6 +77,9 @@
 	DSGA_OP_STO,  ///< store a into temporary storage, indexed by b. return a
 	DSGA_OP_RST,  ///< return b
 	DSGA_OP_STOP, ///< store a into persistent storage, indexed by b, return a
+	DSGA_OP_ROR,  ///< rotate a b positions to the right
+	DSGA_OP_SCMP, ///< (signed) comparision (a < b -> 0, a == b = 1, a > b = 2)
+	DSGA_OP_UCMP, ///< (unsigned) comparision (a < b -> 0, a == b = 1, a > b = 2)
 };