dp4a GPU Virtual ISA NVIDIA

dp4a Integer Arithmetic Instructions

dp4a.atype.btype d, a, b, c;

Four-way byte dot product which is accumulated in 32-bit result.

Encoding

PTX is a virtual instruction set. It has no single, stable native binary encoding - the compiler lowers this instruction to different native machine code depending on the selected NVIDIA target architecture (compute capability). This page intentionally shows no bit-diagram; see the target/version requirements below for what governs how this instruction compiles.
PTX ISA Version Introduced PTX ISA 5.0
Minimum Target sm_61

Syntax Forms

One mnemonic covers many type / state-space / scope / modifier combinations - each row below is an independently valid form.

Syntax Data Types State Space(s) Modifiers Min. Target Description
dp4a.atype.btype d, a, b, c; sm_61 Four-way byte dot product which is accumulated in 32-bit result. Operand a and b are 32-bit inputs which hold 4 byte inputs in packed form for dot product. Operand c has type.u32 if both.atype and. (see the official PTX ISA docs for the full description)

Operands

  • d
    Destination register
  • a
    Source operand
  • b
    Source operand
  • c
    Source operand

At a Glance

Data Types -

Related AMDGPU Concepts

4-Way Dot Product (Accumulate) ↗
equivalent with restrictions
v_dot4_i32_i8 (AMDGPU)
v_dot4_u32_u8 (AMDGPU)

Related

More in Integer Arithmetic Instructions

Reference

NVIDIA PTX ISA

Description

Four-way byte dot product which is accumulated in 32-bit result. Operand a and b are 32-bit inputs which hold 4 byte inputs in packed form for dot product. Operand c has type.u32 if both.atype and.btype are.u32 else operand c has type.s32.

Semantics

d = c; // Extract 4 bytes from a 32bit input and sign or zero extend // based on input type. Va = extractAndSignOrZeroExt_4(a, .atype); Vb = extractAndSignOrZeroExt_4(b, .btype); for (i = 0; i < 4; ++i) { d += Va[i] * Vb[i]; }

Examples

dp4a.u32.u32           d0, a0, b0, c0;
dp4a.u32.s32           d1, a1, b1, c1;

Reproduced from NVIDIA's official PTX ISA documentation for technical accuracy.

Sources