Documentation – Arm Developer
This documentation provides information on A64 general instructions, specifically focusing on the BFM instruction for Arm developers.
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This documentation provides information on A64 general instructions, specifically focusing on the BFM instruction for Arm developers.
BFM Bitfield Move is usually accessed via one of its aliases, which are always preferred for disassembly. If is greater than or equal to , this copies a bitfield of (-+1) bits starting from bit position in the source ...
Jan 9, 2025 · 位字段移动指令(Bitfield move) 将源 寄存器 中从第0位开始的固定宽度字段复制到目标寄存器中的某个固定的位置,或者将源寄存器中某个固定的位位置的字段复制到目标寄存器的第0位。 位字段移位指令通常通过其别名之一访问,在反汇编时总是首选使用这些 ...
这些指令是无条件执行的,但使用条件标志作为指令的额外输入。 提供这组指令是为了取代ARM代码中条件执行的常见用法。
The encodings in this description are named to match the encodings of BFM. The description of BFM gives the operational pseudocode, any constrained unpredictable behavior, and any operational information for this instruction.
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Aug 18, 2023 · 本文介绍了ARM64架构的BFI指令,它用于将一个寄存器的位字段插入到另一个寄存器指定位置,对位操作很有用。 还给出了BFI指令格式和使用示例,同时阐述了ARM为提高效率,使用BFI指令对memset函数进行优化的情况,并对相关汇编代码进行了解析。
Encoding for the 64-bit variant Applies when (sf == 1 && N == 1) BFM , , # , #
Aug 8, 2025 · 本文解析了UBFM指令,重点讲解了当源寄存器位字段复制到目标寄存器时的条件和操作方式,包括不同位数情况下的位移和位字段复制范围。
Documentation – Arm Developer