asr
Arithmetic Shift Right (Register)
ASR <Wd>, <Wn>, <Wm>
Arithmetic shift right by register value.
Pseudocode Operation
Wd ← Wn >> (Wm AND 0x1F) (arithmetic, sign-extended)Example
ASR w0, w1, w2
Encoding
Binary Layout
0
31
0
30
0
29
11010110
28:21
Rm
20:16
0010
15:12
10
11:10
Rn
9:5
Rd
4:0
Operands
-
Wd
Destination 32-bit integer register -
Wn
First source / base 32-bit integer register -
Wm
Shift Reg
Related
Other forms of asr
- asr Arithmetic Shift Right (Immediate)
- asr Arithmetic Shift Right (Immediate 64-bit)
- asr Arithmetic Shift Right (Register 64-bit)
- asr SVE Arithmetic Shift Right (Predicated)
- asr Arithmetic Shift Right (A32)
Across architectures
Logical and Arithmetic Shift : how x86, ARM, RISC-V, and PowerISA each do this.
More in Base
Reference
View in Arm A64 ISA Reference ↗
Arm A64 ISA
Instruction Forms
| Encoding | Instruction | ISA | Bit pattern | ||
|---|---|---|---|---|---|
| 0x1AC02800 | ASR <Wd>, <Wn>, <Wm> | A64 | 0 | 0 | 0 | 11010110 | Rm | 0010 | 10 | Rn | Rd | ||
| 0x9AC02800 | ASR <Xd>, <Xn>, <Xm> | A64 | 1 | 0 | 0 | 11010110 | Rm | 0010 | 10 | Rn | Rd | ||
| 0x13007C00 | ASR <Wd>, <Wn>, #<shift> | A64 | 0 | 00 | 100110 | 0 | immr | 011111 | Rn | Rd | ||
| 0x9340FC00 | ASR <Xd>, <Xn>, #<shift> | A64 | 1 | 00 | 100110 | 1 | immr | 111111 | Rn | Rd | ||
| 0x04008000 | ASR <Zdn>.<T>, <Pg>/M, <Zdn>.<T>, #<const> | A64 | 00000100 | tszh | 00 | 0 | 0 | 0 | 0 | 100 | Pg | tszl | imm3 | Zdn | ||
| 0x04188000 | ASR <Zdn>.<T>, <Pg>/M, <Zdn>.<T>, <Zm>.D | A64 | 00000100 | size | 011 | 0 | 0 | 0 | 100 | Pg | Zm | Zdn | ||
| 0x04108000 | ASR <Zdn>.<T>, <Pg>/M, <Zdn>.<T>, <Zm>.<T> | A64 | 00000100 | size | 010 | 0 | 0 | 0 | 100 | Pg | Zm | Zdn | ||
| 0x04209000 | ASR <Zd>.<T>, <Zn>.<T>, #<const> | A64 | 00000100 | tszh | 1 | tszl | imm3 | 1001 | 0 | 0 | Zn | Zd | ||
| 0x04208000 | ASR <Zd>.<T>, <Zn>.<T>, <Zm>.D | A64 | 00000100 | size | 1 | Zm | 1000 | 0 | 0 | Zn | Zd |
Description
Arithmetic Shift Right (register) shifts a register value right by a variable number of bits, shifting in copies of its sign bit, and writes the result to the destination register. The remainder obtained by dividing the second source register by the data size defines the number of bits by which the first source register is right-shifted.