CSNEG

Conditional Select Negation returns, in the destination register, the value of the first source register if the condition is TRUE, and otherwise returns the negated value of the second source register.

This instruction is used by the alias CNEG.

313029282726252423222120191817161514131211109876543210
sf1011010100Rmcond01RnRd
opSo2

32-bit (sf == 0)

CSNEG <Wd>, <Wn>, <Wm>, <cond>

64-bit (sf == 1)

CSNEG <Xd>, <Xn>, <Xm>, <cond>

integer d = UInt(Rd); integer n = UInt(Rn); integer m = UInt(Rm); constant integer datasize = 32 << UInt(sf); bits(4) condition = cond;

Assembler Symbols

<Wd>

Is the 32-bit name of the general-purpose destination register, encoded in the "Rd" field.

<Wn>

Is the 32-bit name of the first general-purpose source register, encoded in the "Rn" field.

<Wm>

Is the 32-bit name of the second general-purpose source register, encoded in the "Rm" field.

<cond>

Is one of the standard conditions, encoded in the standard way, and encoded in cond:

cond <cond>
0000 EQ
0001 NE
0010 CS
0011 CC
0100 MI
0101 PL
0110 VS
0111 VC
1000 HI
1001 LS
1010 GE
1011 LT
1100 GT
1101 LE
1110 AL
1111 NV
<Xd>

Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" field.

<Xn>

Is the 64-bit name of the first general-purpose source register, encoded in the "Rn" field.

<Xm>

Is the 64-bit name of the second general-purpose source register, encoded in the "Rm" field.

Alias Conditions

AliasIs preferred when
CNEG!(cond IN {'111x'}) && Rn == Rm

Operation

bits(datasize) result; if ConditionHolds(condition) then result = X[n, datasize]; else result = NOT(X[m, datasize]) + 1; X[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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