; Load destination far pointer (segment in ES, offset in DI) MOV AX, [dest_segment] MOV ES, AX MOV DI, [dest_offset]
Because LDS touches segment registers, it’s considered a instruction in some contexts—it can stall the pipeline. In modern flat-model code, two simple MOV instructions might even be faster than LDS due to better pipelining and out-of-order execution. But in its heyday on an 8086, LDS was a performance win. x86 lds
It reads the subsequent bytes and moves that value into the DS register. ; Load destination far pointer (segment in ES,
The core purpose of LDS is to load a full pointer from memory into a general-purpose register and the (Data Segment) register in a single atomic operation. Instruction Syntax: LDS destination, source It reads the subsequent bytes and moves that
Writing kernels that interface with legacy hardware.
Without LDS and LES , this snippet would require manually loading each segment and offset with MOV instructions, consuming more opcodes and risking a stale segment register if an interrupt occurred mid-sequence.