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zero register

A register that always reads as 0 and ignores writes (xzr on ARM64, x0 on RISC-V).

A hard-wired zero register reads as zero and discards writes, letting one instruction form serve as move, compare or discard.

Examples

  • ARM64's xzr and RISC-V's x0 always read as 0, so mov x1, xzr clears x1.

See also

stack pointer return address
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