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CMGT (register)

Compare signed Greater than (vector). This instruction compares each vector element in the first source SIMD&FP register with the corresponding vector element in the second source SIMD&FP register and if the first signed integer value is greater than the second signed integer value 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
01011110size1Rm001101RnRd
Ueq

Scalar

CMGT <V><d>, <V><n>, <V><m>

integer d = UInt(Rd); integer n = UInt(Rn); integer m = UInt(Rm); if size != '11' then ReservedValue(); integer esize = 8 << UInt(size); integer datasize = esize; integer elements = 1; boolean unsigned = (U == '1'); boolean cmp_eq = (eq == '1');

Vector

313029282726252423222120191817161514131211109876543210
0Q001110size1Rm001101RnRd
Ueq

Vector

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

integer d = UInt(Rd); integer n = UInt(Rn); integer m = UInt(Rm); if size:Q == '110' then ReservedValue(); integer esize = 8 << UInt(size); integer datasize = if Q == '1' then 128 else 64; integer elements = datasize DIV esize; boolean unsigned = (U == '1'); boolean cmp_eq = (eq == '1');

Assembler Symbols

<V> Is a width specifier, encoded in size:
size<V>
0xRESERVED
10RESERVED
11D
Is a width specifier, encoded in size:
size<V>
0xRESERVED
10RESERVED
11D
<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:
sizeQ<T>
0008B
00116B
0104H
0118H
1002S
1014S
110RESERVED
1112D
Is an arrangement specifier, encoded in size:Q:
sizeQ<T>
0008B
00116B
0104H
0118H
1002S
1014S
110RESERVED
1112D
<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]; bits(datasize) operand2 = V[m]; bits(datasize) result; integer element1; integer element2; boolean test_passed; for e = 0 to elements-1 element1 = Int(Elem[operand1, e, esize], unsigned); element2 = Int(Elem[operand2, e, esize], unsigned); test_passed = if cmp_eq then element1 >= element2 else element1 > element2; Elem[result, e, esize] = if test_passed then Ones() else Zeros(); V[d] = result;

Operational information

If PSTATE.DIT is 1:


Internal version only: isa v29.05v27.02, AdvSIMD v26.0, pseudocode v35.3v34.2.2 ; Build timestamp: 2018-06-16T092018-03-28T19:4555

Copyright © 2010-2018 ARM Limited or its affiliates. All rights reserved. This document is Non-Confidential.

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