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

313029282726252423222120191817161514131211109876543210
01011110111Rm100011RnRd
Usizeopcode

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

313029282726252423222120191817161514131211109876543210
0Q001110size1Rm100011RnRd
Uopcode

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:


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

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