FSUB (vectors, unpredicated) -- A64

This instruction subtracts all floating-point elements of the second source vector from the corresponding elements of the first source vector, and places the results in the corresponding elements of the destination vector. This instruction is unpredicated.

SVE
(FEAT_SVE || FEAT_SME)

Decode for this encoding

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); end; let esize : integer{} = 8 << UInt(size); let n : integer = UInt(Zn); let m : integer = UInt(Zm); let d : integer = UInt(Zd);

Assembler Symbols

<Zd>	Is the name of the destination scalable vector register, encoded in the "Zd" field.

<T>

Is the size specifier, encoded in size:

size	<T>
01	H
10	S
11	D

<Zn>	Is the name of the first source scalable vector register, encoded in the "Zn" field.

<Zm>	Is the name of the second source scalable vector register, encoded in the "Zm" field.

Operation

CheckSVEEnabled(); let VL : integer{} = CurrentVL(); let elements : integer = VL DIV esize; let operand1 : bits(VL) = Z{}(n); let operand2 : bits(VL) = Z{}(m); var result : bits(VL); for e = 0 to elements-1 do let element1 : bits(esize) = operand1[e*:esize]; let element2 : bits(esize) = operand2[e*:esize]; result[e*:esize] = FPSub{esize}(element1, element2, FPCR()); end; Z{VL}(d) = result;

2026-03_rel 2026-03-26 20:48:11

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	1	1	0	0	1	0	1	!= 00		0	Zm					0	0	0	0	0	1	Zn					Zd
								size											opc