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NEGS

Negate, setting flags

This instruction negates an optionally-shifted register value, and writes the result to the destination register. It updates the condition flags based on the result.

This is an alias of SUBS (shifted register). This means:

313029282726252423222120191817161514131211109876543210
sf1101011shift0Rmimm611111!= 11111
opSRnRd

32-bit encoding

(sf == 0)

NEGS <Wd>, <Wm>{, <shift> #<amount>}

is equivalent to

SUBS <Wd>, WZR, <Wm>{, <shift> #<amount>}

and is always the preferred disassembly.

64-bit encoding

(sf == 1)

NEGS <Xd>, <Xm>{, <shift> #<amount>}

is equivalent to

SUBS <Xd>, XZR, <Xm>{, <shift> #<amount>}

and is always the preferred disassembly.

Assembler Symbols

<Wd>

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

<Wm>

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

<shift>

Is the optional shift type to be applied to the second source operand, defaulting to LSL and encoded in shift:

shift <shift>
00 LSL
01 LSR
10 ASR
11 RESERVED
<amount>

For the "32-bit" variant: is the shift amount, in the range 0 to 31, defaulting to 0 and encoded in the "imm6" field.

For the "64-bit" variant: is the shift amount, in the range 0 to 63, defaulting to 0 and encoded in the "imm6" field.

<Xd>

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

<Xm>

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

Operation

The description of SUBS (shifted register) gives the operational pseudocode for this instruction.

Operational Information

The description of SUBS (shifted register) gives the operational information for this instruction.


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