assembly - Why might one use the xzr register instead of the …
Mar 15, 2017 · What xzr gives us, however - in addition to a dummy register as per @InfinitelyManic's answer - is access to a zero-valued operand without having to load and …
In ARM64 assembly code, when is register 31 XZR versus SP?
May 1, 2020 · The ARM Reference manual writes Xn when XZR can be used and Xn|SP when SP can be used. See the introduction to §5 “A64 INSTRUCTION SET.” See the introduction to …
Different encoding for arm64 "add x1, sp, x2, lsl #1" than with xzr
When XZR is used, the field says something like <Xn> and the text just says “general-purpose register.” You need to know which instruction you are decoding to know whether to decode …
Is Zero Register 'zr' in aarch64 essentially ground?
Sep 20, 2018 · The zero register xzr resp. wzr is a cute design trick in the Aarch64 ISA. It's register number is 31, just as the stack pointer sp resp. wsp. Depending on the context, …
ARMv8: XZR use in LDUR/STUR instructions assembler error
Nov 19, 2018 · It is supposed XZR can be used in any register field of ARMv8 ISA, but when I try use in indexed addressing for load/store intruction, I always obtain errors: ex2.s:3: Error: …
Single instruction for clearing the Z flag on ARM64?
Apr 3, 2023 · The tricky thing here is ARM64's encoding convention that "register 31" is XZR in some instruction and SP in others, chosen according to which they thought would be more …
recursion - Recursive Fibonacci in ARM - Stack Overflow
Apr 13, 2017 · For the sake of avoiding spoon-feeding, I wrote a LEGv8 program that finds Fibonacci sequence using recursion
arm - What's the difference between MOV, MOVZ, MOVN and …
Nov 13, 2018 · XZR is the zero register and its value is always zero. The XZR and the SP share are identified by the same number (31), that is why an ORR instruction cannot be used when …
operand must be an int register in armv8 - Stack Overflow
Dec 9, 2022 · add-immediate with xzr is impossible, since the same syntax compilers use for adding 1 (add reg, reg, #1) doesn't assemble if XZR is the source register. For some …
Which processor part does a MOV instruction in armv8 use
Dec 3, 2019 · XZR is an alias for a register that always returns 0 and can't be changed to anything but 0. It's new in AArch64, but other RISCs like MIPS have always had a zero register. It's new …