MOV
Copy data
Copy a register, immediate or memory value to the destination.
| Form | Bits | Requires | Encoding |
|---|---|---|---|
MOV r32_dst, r32_src | 32 | x86-64 | 89 /r |
MOV r32, m32 | 32 | x86-64 | 8B /r |
MOV m32, r32 | 32 | x86-64 | 89 /r |
MOV r32, imm32 | 32 | x86-64 | b8+r |
MOV r64_dst, r64_src | 64 | x86-64 | REX.W + 89 /r |
MOV r64, m64 | 64 | x86-64 | REX.W + 8B /r |
MOV m64, r64 | 64 | x86-64 | REX.W + 89 /r |
MOV r64, imm64 | 64 | x86-64 | REX.W + b8+r |
MOV r64, imm32 | 64 | x86-64 | REX.W + C7 /0 iz |
Operation#
Pseudo-C · selected form
dst = srcExact upstream semantics
Standard variant
let result := src;Architectural details#
- Flags
- RFLAGS unchanged.
- Destination
- Writes the low 32 bits and clears the corresponding 64-bit register’s upper half.
- Encoding
89 /r- Operands
r32_dstwrite · 32 bitsr32_srcread · 32 bits
- Coverage
- Selected scalar forms in 64-bit execution mode. 8/16-bit arithmetic, APX and unlisted encoding alternatives are outside this selection.
Exception information & execution requirements
#UD
Imported exceptions are checks exposed by this XML form; memory, stack, instruction-fetch and called architectural helpers can introduce additional faults.
Feature availability alone does not guarantee execution: OS state and execution-level controls also apply. Use the linked architecture documentation for the full exception conditions.
Sources & provenance#
Technical fields are imported from pinned upstream files. Explanations and explorer behavior are maintained separately.
Intel · MOV-Move.xml
- Revision
4ebe7f0ac1bd00f46244c49bb72c503ce368def7- SHA-256
805d79d9b1b82ac06dff3aaee20f60a4666fdf8ede3ef9239480b881f822d2c9- Terms
- Intel SDM terms; see License.md