CCMN (register)

Conditional Compare Negative (register) sets the value of the condition flags to the result of the comparison of a register value and the inverse of another register value if the condition is TRUE, and an immediate value otherwise.

313029282726252423222120191817161514131211109876543210
sf0111010010Rmcond00Rn0nzcv
op

32-bit (sf == 0)

CCMN <Wn>, <Wm>, #<nzcv>, <cond>

64-bit (sf == 1)

CCMN <Xn>, <Xm>, #<nzcv>, <cond>

integer n = UInt(Rn); integer m = UInt(Rm); integer datasize = if sf == '1' then 64 else 32; boolean sub_op = (op == '1'); bits(4) condition = cond; bits(4) flags = nzcv;

Assembler Symbols

<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.

<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.

<nzcv>

Is the flag bit specifier, an immediate in the range 0 to 15, giving the alternative state for the 4-bit NZCV condition flags, encoded in the "nzcv" field.

<cond>

Is one of the standard conditions, encoded in the "cond" field in the standard way.

Operation

if ConditionHolds(condition) then bits(datasize) operand1 = X[n]; bits(datasize) operand2 = X[m]; bit carry_in = '0'; if sub_op then operand2 = NOT(operand2); carry_in = '1'; (-, flags) = AddWithCarry(operand1, operand2, carry_in); PSTATE.<N,Z,C,V> = flags;

Operational information

If PSTATE.DIT is 1:


Internal version only: isa v33.11seprel, AdvSIMD v29.05, pseudocode v2021-09_rel, sve v2021-09_rc3d ; Build timestamp: 2021-10-06T11:41

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