You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: leopard.go
    path of file: ./repos/scan4all/vendor/github.com/klauspost/reedsolomon
    
    the code of the file until where you have to start completion: package reedsolomon

// This is a O(n*log n) implementation of Reed-Solomon
// codes, ported from the C++ library https://github.com/catid/leopard.
//
// The implementation is based on the paper
//
// S.-J. Lin, T. Y. Al-Naffouri, Y. S. Han, and W
    
func ifftDIT4Ref(work [][]byte, dist int, log_m01, log_m23, log_m02 ffe, o *options) {
	// First layer:
	if log_m01 == modulus {
		sliceXor(work[0], work[dist], o)
	} else {
		ifftDIT2(work[0], work[dist], log_m01, o)
	}

	if log_m23 == modulus {
		sliceXor(work[dist*2], work[dist*3], o)
	} else {
		ifftDIT2(work[dist*2], work[dist*3], log_m23, o)
	}

	// Second layer:
	if log_m02 == modulus {
		sliceXor(work[0], work[dist*2], o)
		sliceXor(work[dist], work[dist*3], o)
	} else {
		ifftDIT2(work[0], work[dist*2], log_m02, o)
		ifftDIT2(work[dist], work[dist*3], log_m02, o)
	}
}