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Instruction

TOP4BUUD

ACE outer product of two ZMM registers of unsigned bytes, four per dword, accumulated into a tile of 32-bit integers.

Extensions
Forms
1 (1 EVEX)
Data
Intel XED v2026.08.23

Forms

Every encoding of TOP4BUUD that Intel XED knows, one row per XED instruction form (iform). How to read the notation.
InstructionEncodingRequires
TOP4BUUD tmm, zmm, zmm 64-bit mode only TOP4BUUD_TMMu32_ZMMu8_ZMMu8EVEX.512.NP.0F38.W0 5E /rACE v1

CPUID and processors

Each form belongs to an XED ISA set. A form can be used when the processor reports every CPUID bit of one of its ISA set's alternatives.

CPUID requirements and processors of the XED ISA sets above. Alternatives are separated by “or”; processors follow XED’s chip model, which covers AMD processors up to Zen 2.
ISA setCPUIDProcessors in XED
ACE_1

ACE v1
CPUID.(EAX=07H,ECX=1):ECX[11] ACE
CPUID.(EAX=1DH,ECX=2):EAX[7:0] ≥ 1 ACE version

None yet: XED lists these instructions only under its placeholder for future processors.

More ACE instructions

Sources

  1. Intel XED v2026.08.23 (commit 0bcb6237345c): forms, encodings, ISA sets, CPUID bits and chip model.
  2. x86 Ecosystem Advisory Group: AI Compute Extensions (ACE) Specification, version 1.16.2 (July 2026)

The tables are derived from Intel XED, Copyright Intel Corporation, licensed under the Apache License 2.0; x86-64.net converted and reformatted them. The text is our own.