UMOV -- A64

Unsigned Move vector element to general-purpose register. This instruction reads the unsigned integer from the source SIMD&FP register, zero-extends it to form a 32-bit or 64-bit value, and writes the result to the destination general-purpose register.

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.

integer d = UInt(Rd); integer n = UInt(Rn); constant integer size = LowestSetBit(imm5); if size > 3 then UNDEFINED; constant integer esize = 8 << size; constant integer datasize = 32 << UInt(Q); if datasize == 64 && esize < 64 then UNDEFINED; if datasize == 32 && esize >= 64 then UNDEFINED; constant integer index = UInt(imm5<4:size+1>); constant integer idxdsize = 64 << UInt(imm5<4>);

Assembler Symbols

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

<Vn>	Is the name of the SIMD&FP source register, encoded in the "Rn" field.

<Ts>

Is an element size specifier, encoded in imm5:

imm5	<Ts>
xx000	RESERVED
xxxx1	B
xxx10	H
xx100	S

<index>

For the 32-bit variant: is the element index encoded in imm5:

imm5	<index>
xx000	RESERVED
xxxx1	UInt(imm5<4:1>)
xxx10	UInt(imm5<4:2>)
xx100	UInt(imm5<4:3>)

For the 64-bit variant: is the element index encoded in "imm5<4>".

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

Alias Conditions

Alias	Of variant	Is preferred when
MOV (to general)	32-bit	imm5 IN {'xx100'}
MOV (to general)	64-bit	imm5 IN {'x1000'}

Operation

if index == 0 then CheckFPEnabled64(); else CheckFPAdvSIMDEnabled64(); bits(idxdsize) operand = V[n, idxdsize]; X[d, datasize] = ZeroExtend(Elem[operand, index, esize], datasize);

Operational information

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.

Internal version only: aarchmrs v2023-12_rel, pseudocode v2023-12_rel, sve v2023-12_rel ; Build timestamp: 2023-12-15T16:46

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
0	Q	0	0	1	1	1	0	0	0	0	imm5					0	0	1	1	1	1	Rn					Rd
		op															imm4

UMOV

32-bit (Q == 0)

64-bit (Q == 1 && imm5 == x1000)

Assembler Symbols

Alias Conditions

Operation

Operational information