added subtractNoWrap(BigInteger)

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/address/AbstractAddressSpace.java

@@ -414,6 +414,26 @@ abstract class AbstractAddressSpace implements AddressSpace {
 		long resultOffset = NumericUtilities.bigIntegerToUnsignedLong(newOffset);
 		return getUncheckedAddress(resultOffset);
 	}
+	@Override
+	public Address subtractNoWrap(GenericAddress addr, BigInteger displacement)
+			throws AddressOverflowException {
+
+		if (displacement.equals(BigInteger.ZERO)) {
+			return addr;
+		}
+		testAddressSpace(addr);
+		BigInteger addrOff = addr.getOffsetAsBigInteger();
+		BigInteger maxOff = maxAddress.getOffsetAsBigInteger();
+		BigInteger minOff = minAddress.getOffsetAsBigInteger();
+		BigInteger newOffset = addrOff.subtract(displacement);
+		if (newOffset.compareTo(minOff) < 0 || newOffset.compareTo(maxOff) > 0) {
+			throw new AddressOverflowException(
+				"Address Overflow in add: " + addr + " + " + displacement);
+		}
+
+		long resultOffset = NumericUtilities.bigIntegerToUnsignedLong(newOffset);
+		return getUncheckedAddress(resultOffset);
+	}
 
 	@Override
 	public Address add(Address addr, long displacement) throws AddressOutOfBoundsException {

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/address/Address.java

@@ -254,6 +254,7 @@ public interface Address extends Comparable<Address> {
 	public Address addNoWrap(long displacement) throws AddressOverflowException;
 
 	public Address addNoWrap(BigInteger displacement) throws AddressOverflowException;
+	public Address subtractNoWrap(BigInteger displacement) throws AddressOverflowException;
 
 	/**
 	 * Creates a new address (possibly in a new space) by adding the displacement to this address.

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/address/AddressSpace.java

@@ -363,6 +363,17 @@ public interface AddressSpace extends Comparable<AddressSpace> {
 	public Address addNoWrap(GenericAddress addr, BigInteger displacement)
 			throws AddressOverflowException;
 
+	/**
+	 * Creates a new address by subtracting the displacement to the given address. The
+	 * new address will NOT wrap!  
+	 * @param addr the original address.
+	 * @param displacement  the displacement to subtract.
+	 * @return The new address created by subtracting the displacement to addr.offset.
+	 * @throws AddressOverflowException if the addition would cause a wrap,
+	 */
+	public Address subtractNoWrap(GenericAddress addr, BigInteger displacement)
+			throws AddressOverflowException;
+
 	/**
 	 * Creates a new address (possibly in a new space) by adding the given 
 	 * displacement from the given address.

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/address/GenericAddress.java

@@ -176,6 +176,13 @@ public class GenericAddress implements Address {
 		}
 		return addrSpace.addNoWrap(this, displacement);
 	}
+	@Override
+	public Address subtractNoWrap(BigInteger displacement) throws AddressOverflowException {
+		if (displacement.equals(BigInteger.ZERO)) {
+			return this;
+		}
+		return addrSpace.subtractNoWrap(this, displacement);
+	}
 
 	@Override
 	public Address add(long displacement) {