protected AssemblyResolution solveOrBackfill(PatternExpression exp, MaskedLong goal,
			Map<String, Long> vals, AssemblyResolvedPatterns cur, String description) {
		try {
			return SOLVER.solve(this, exp, goal, vals, cur, description);
		}
		catch (NeedsBackfillException bf) {
			int fieldLength = SOLVER.getInstructionLength(exp);
			return backfill(exp, goal, fieldLength, description);
		}
	}
Attempt to solve an expression

@param exp the expression to solve
@param goal the desired value of the expression
@param cur the resolved constructor so far
@param description a description of the result
@return the encoded solution, or a backfill record
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/assembler/sleigh/sem/AbstractAssemblyResolutionFactory.java