CMN (extended register)
Compare negative (extended register)
This instruction adds a register value and a
sign or zero-extended register value, followed by an optional
left shift amount. The argument that is extended from the
<Rm> register can be a byte, halfword, word, or
doubleword. It updates the condition flags based on the
result, and discards the result.
If PSTATE.DIT is 1:
The execution time of this instruction is independent of:
The values of the data supplied in any of its registers.
The values of the NZCV flags.
The response of this instruction to asynchronous exceptions does not vary based on:
The values of the data supplied in any of its registers.
The values of the NZCV flags.
ADDS (extended register)
0
1
0
1
0
1
1
0
0
1
1
1
1
1
1
0
CMN <Wn|WSP>, <Wm>{, <extend> {#<amount>}}
ADDS WZR, <Wn|WSP>, <Wm>{, <extend> {#<amount>}}
Unconditionally
1
CMN <Xn|SP>, <R><m>{, <extend> {#<amount>}}
ADDS XZR, <Xn|SP>, <R><m>{, <extend> {#<amount>}}
Unconditionally
<Wn|WSP>
Is the 32-bit name of the first source general-purpose register or stack pointer, encoded in the "Rn" field.
<Wm>
Is the 32-bit name of the second general-purpose source register, encoded in the "Rm" field.
<extend>
For the 32-bit variant: is the extension to be applied to the second source operand,
option
<extend>
000
UXTB
001
UXTH
010
LSL|UXTW
011
UXTX
100
SXTB
101
SXTH
110
SXTW
111
SXTX
If "Rn" is '11111' (WSP) and "option" is '010' then LSL is preferred, but may be omitted when "imm3" is '000'. In all other cases <extend> is required and must be UXTW when "option" is '010'.
<extend>
For the 64-bit variant: is the extension to be applied to the second source operand,
option
<extend>
000
UXTB
001
UXTH
010
UXTW
011
LSL|UXTX
100
SXTB
101
SXTH
110
SXTW
111
SXTX
If "Rn" is '11111' (SP) and "option" is '011' then LSL is preferred, but may be omitted when "imm3" is '000'. In all other cases <extend> is required and must be UXTX when "option" is '011'.
<amount>
Is the left shift amount to be applied after extension in the range 0 to 4, defaulting to 0, encoded in the "imm3" field. It must be absent when <extend> is absent, is required when <extend> is LSL, and is optional when <extend> is present but not LSL.
<Xn|SP>
Is the 64-bit name of the first source general-purpose register or stack pointer, encoded in the "Rn" field.
<R>
Is a width specifier,
option
<R>
00x
W
010
W
x11
X
10x
W
110
W
<m>
Is the number [0-30] of the second general-purpose source register or the name ZR (31), encoded in the "Rm" field.