Base Instructions | SIMD&FP Instructions | SVE Instructions | SME Instructions | Index by Encoding | Shared Pseudocode | Proprietary Notice

## CMTST

Compare bitwise Test bits nonzero (vector). This instruction reads each vector element in the first source SIMD&FP register, performs an AND with the corresponding vector element in the second source SIMD&FP register, and if the result is not zero, sets every bit of the corresponding vector element in the destination SIMD&FP register to one, otherwise sets every bit of the corresponding vector element in the destination SIMD&FP register to zero.

Depending on the settings in the CPACR_EL1, CPTR_EL2, and CPTR_EL3 registers, and the current Security state and Exception level, an attempt to execute the instruction might be trapped.

It has encodings from 2 classes: Scalar and Vector

### Scalar

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
0 | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | Rm | 1 | 0 | 0 | 0 | 1 | 1 | Rn | Rd
| U |  | size |  |  | opcode |  |  |

####

CMTST D<d>, D<n>, D<m>

integer d = UInt(Rd); integer n = UInt(Rn); integer m = UInt(Rm); if size != '11' then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer datasize = esize; integer elements = 1; boolean and_test = (U == '0');

### Vector

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
0 | Q | 0 | 0 | 1 | 1 | 1 | 0 | size | 1 | Rm | 1 | 0 | 0 | 0 | 1 | 1 | Rn | Rd
|  | U |  |  |  |  | opcode |  |  |

####

CMTST <Vd>.<T>, <Vn>.<T>, <Vm>.<T>

integer d = UInt(Rd); integer n = UInt(Rn); integer m = UInt(Rm); if size:Q == '110' then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer datasize = 64 << UInt(Q); integer elements = datasize DIV esize; boolean and_test = (U == '0');

### Assembler Symbols

<d> | Is the number of the SIMD&FP destination register, in the "Rd" field.

<n> | Is the number of the first SIMD&FP source register, encoded in the "Rn" field.

<m> | Is the number of the second SIMD&FP source register, encoded in the "Rm" field.

<Vd> | Is the name of the SIMD&FP destination register, encoded in the "Rd" field.

<T> | Is an arrangement specifier, encoded in size:Q:
size | Q | <T>
--- | --- | ---
00 | 0 | 8B
00 | 1 | 16B
01 | 0 | 4H
01 | 1 | 8H
10 | 0 | 2S
10 | 1 | 4S
11 | 0 | RESERVED
11 | 1 | 2D

<Vn> | Is the name of the first SIMD&FP source register, encoded in the "Rn" field.

<Vm> | Is the name of the second SIMD&FP source register, encoded in the "Rm" field.

### Operation

CheckFPAdvSIMDEnabled64(); bits(datasize) operand1 = V[n, datasize]; bits(datasize) operand2 = V[m, datasize]; bits(datasize) result; bits(esize) element1; bits(esize) element2; boolean test_passed; for e = 0 to elements-1 element1 = Elem[operand1, e, esize]; element2 = Elem[operand2, e, esize]; if and_test then test_passed = !IsZero(element1 AND element2); else test_passed = (element1 == element2); Elem[result, e, esize] = if test_passed then Ones(esize) else Zeros(esize); V[d, datasize] = result;

### Operational information

If PSTATE.DIT is 1:

- The execution time of this instruction is independent of:
  - The values of the data supplied in any of its registers.
  - The values of the NZCV flags.
- The response of this instruction to asynchronous exceptions does not vary based on:
  - The values of the data supplied in any of its registers.
  - The values of the NZCV flags.

Base Instructions | SIMD&FP Instructions | SVE Instructions | SME Instructions | Index by Encoding | Shared Pseudocode | Proprietary Notice

Internal version only: aarchmrs v2024-03_relA, pseudocode v2024-03_rel, sve v2024-03_rel ; Build timestamp: 2024-03-26T09:45

Copyright © 2010-2024 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.