BFSUB (unpredicated)

BFloat16 subtract (unpredicated)

This instruction subtracts all BFloat16 elements of the second source vector from corresponding BFloat16 elements of the first source vector and places the results in the corresponding elements of the destination vector.

This instruction follows SVE2 non-widening BFloat16 numerical behaviors.

This instruction is unpredicated.

ID_AA64ZFR0_EL1.B16B16 indicates whether this instruction is implemented.

SVE2 class

(FEAT_SVE_B16B16)

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	0	0	0	Zm					0	0	0	0	0	1	Zn					Zd
								size											opc

Encoding

BFSUB <Zd>.H, <Zn>.H, <Zm>.H

Decode

if !IsFeatureImplemented(FEAT_SVE_B16B16) then EndOfDecode(Decode_UNDEF); constant integer n = UInt(Zn); constant integer m = UInt(Zm); constant integer d = UInt(Zd);

Assembler Symbols

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

<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

if IsFeatureImplemented(FEAT_SME2) then CheckSVEEnabled(); else CheckNonStreamingSVEEnabled(); constant integer VL = CurrentVL; constant integer elements = VL DIV 16; constant bits(VL) operand1 = Z[n, VL]; constant bits(VL) operand2 = Z[m, VL]; bits(VL) result; for e = 0 to elements-1 constant bits(16) element1 = Elem[operand1, e, 16]; constant bits(16) element2 = Elem[operand2, e, 16]; Elem[result, e, 16] = BFSub(element1, element2, FPCR); Z[d, VL] = result;