RISC-V ISA Explorer · Float & Numerics (Zf*)

Zfh: Half-Precision FP (16-bit)

Ratified 2021-11 · version 1.0.0

IEEE 754-2008 16-bit arithmetic, for workloads where reduced precision saves memory and power.

Typical use: Reduced-precision inference and signal processing

Specification

Open Zfh in the explorer

Dependencies

Requires

Zfhmin

Instructions (26)

Mnemonic	Name	Encoding	Match	Mask
`FADD.H`		`0000010------------------1010011`	`0x4000053`	`0xfe00007f`
`FCLASS.H`		`111001000000-----001-----1010011`	`0xe4001053`	`0xfff0707f`
`FCVT.H.L`	Floating-point Convert Long to Half-precision	`110101000010-------------1010011`	`0xd4200053`	`0xfff0007f`
`FCVT.H.LU`	Floating-point Convert Unsigned Long to Half-precision	`110101000011-------------1010011`	`0xd4300053`	`0xfff0007f`
`FCVT.H.W`	Floating-point Convert Word to Half-precision	`110101000000-------------1010011`	`0xd4000053`	`0xfff0007f`
`FCVT.H.WU`	Floating-point Convert Unsigned Word to Half-precision	`110101000001-------------1010011`	`0xd4100053`	`0xfff0007f`
`FCVT.L.H`	Floating-point Convert Half-precision to Long	`110001000010-------------1010011`	`0xc4200053`	`0xfff0007f`
`FCVT.LU.H`	Floating-point Convert Half-precision to Unsigned Long	`110001000011-------------1010011`	`0xc4300053`	`0xfff0007f`
`FCVT.W.H`	Floating-point Convert Half-precision to Word	`110001000000-------------1010011`	`0xc4000053`	`0xfff0007f`
`FCVT.WU.H`	Floating-point Convert Half-precision to Word	`110001000001-------------1010011`	`0xc4100053`	`0xfff0007f`
`FDIV.H`		`0001110------------------1010011`	`0x1c000053`	`0xfe00007f`
`FEQ.H`		`1010010----------010-----1010011`	`0xa4002053`	`0xfe00707f`
`FLE.H`		`1010010----------000-----1010011`	`0xa4000053`	`0xfe00707f`
`FLT.H`		`1010010----------001-----1010011`	`0xa4001053`	`0xfe00707f`
`FMADD.H`		`-----10------------------1000011`	`0x4000043`	`0x600007f`
`FMAX.H`		`0010110----------001-----1010011`	`0x2c001053`	`0xfe00707f`
`FMIN.H`		`0010110----------000-----1010011`	`0x2c000053`	`0xfe00707f`
`FMSUB.H`		`-----10------------------1000111`	`0x4000047`	`0x600007f`
`FMUL.H`		`0001010------------------1010011`	`0x14000053`	`0xfe00007f`
`FNMADD.H`		`-----10------------------1001111`	`0x400004f`	`0x600007f`
`FNMSUB.H`		`-----10------------------1001011`	`0x400004b`	`0x600007f`
`FSGNJ.H`		`0010010----------000-----1010011`	`0x24000053`	`0xfe00707f`
`FSGNJN.H`		`0010010----------001-----1010011`	`0x24001053`	`0xfe00707f`
`FSGNJX.H`		`0010010----------010-----1010011`	`0x24002053`	`0xfe00707f`
`FSQRT.H`		`010111000000-------------1010011`	`0x5c000053`	`0xfff0007f`
`FSUB.H`		`0000110------------------1010011`	`0xc000053`	`0xfe00007f`