v_maxmin_f16 GPU Native ISA AMD Vector

Vector Arithmetic

v_maxmin_f16

Select the maximum of the first two half-precision float inputs and then select the minimum of that result and third half-precision float input.

Also written as v_maxmin_num_f16. AMD's machine-readable ISA specification lists this name for the same instruction.

Encoding

Binary Layout (AMD RDNA 3.5)
NEG
63:61
OMOD
60:59
SRC2
58:50
SRC1
49:41
SRC0
40:32
110101
31:26
1001100000
25:16
CLAMP
15
OP_SEL
14:11
ABS
10:8
VDST
7:0
 

The ENC_VOP3 layout from AMD's machine-readable ISA specification (AMD RDNA 3.5). Opcode 608 in OP rebuilds 0x00000000D6600000, an identifier AMD lists for this encoding. The same in AMD RDNA 3.

Format VOP3
Width 64 bits
Opcode 608
Identifier 0x00000000D6600000

Operands

  • VDST
    Written. Operand must be a vector GPR. Uses an 8-bit operand field. Data format: 16-bit half-precision floating point value. (OPR_VGPR, FMT_NUM_F16)
  • SRC0
    Read. All operands. Covers all operands that are allowed as scalar or vector sources. Data format: 16-bit half-precision floating point value. (OPR_SRC, FMT_NUM_F16)
  • SRC1
    Read. All operands. Covers all operands that are allowed as scalar or vector sources. Data format: 16-bit half-precision floating point value. (OPR_SRC, FMT_NUM_F16)
  • SRC2
    Read. All operands. Covers all operands that are allowed as scalar or vector sources. Data format: 16-bit half-precision floating point value. (OPR_SRC, FMT_NUM_F16)

In AMD's order, as its machine-readable ISA specification lists them for the ENC_VOP3 encoding (AMD RDNA 3.5).

GFX Target Compatibility

TargetSupport
gfx1100✅ Supported

Related

More in Vector Arithmetic

Reference

AMDGPU / GFX ISA

Description

Select the maximum of the first two half-precision float inputs and then select the minimum of that result and third half-precision float input. Store the final result into a vector register.

Example

v_maxmin_f16 v5, v1, v2, s3

A real instruction accepted by the LLVM assembler, taken verbatim from LLVM's own AMDGPU MC test suite. Not from an AMD document, and not authored here.

Sources