Advanced Matrix Extensions
Advanced Matrix Extensions (AMX), also known as Intel Advanced Matrix Extensions (Intel AMX), are extensions to the x86 instruction set architecture (ISA) for microprocessors from Intel and Advanced Micro Devices (AMD) designed to work on matrices to accelerate artificial intelligence (AI) / machine learning (ML) -related workloads.

Extensions
AMX was introduced by Intel in June 2020 and first supported by Intel with the Sapphire Rapids microarchitecture for Xeon servers, planned for 2022. It introduced 2-dimensional registers called tiles upon which accelerators can perform operations. It is intended as an extensible architecture, the first accelerator implemented is called tile matrix multiply unit (TMUL).

Tile matrix multiply unit
TMUL unit supports BF16 and INT8 input types. The register file consists of 8 tiles, each with 16 rows of size 64-byte (32 BF16 or 64 INT8 values). The only supported operation as for now is matrix multiplication

Software support 
Compiler and assembler support
 LLVM initial support committed at 1 July 2020
 GNU Assembler (GAS) initial support committed at 25 June 2020
 GCC patches have been posted for version 11
Operating system support
glibc support for detecting AMX feature in CPUs committed at 25 Jun 2020
Linux kernel support will not be available until at least 5.16

References

External links 
 Intel Intrinsics Guide
 Wikichip: Advanced Matrix Extension (AMX) - x86

X86 instructions
SIMD computing
Advanced Micro Devices technologies