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Extensions - x86
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Extensions(all)
The x86 ISA has gone through numerous iterations that added new instructions to performs specific tasks. These collections of new instructions are grouped into extensions. Different microprocessor models have different levels of support for certain extensions.
Overview[edit]
The x86 ISA has been developed over the course of forty years. Various extensions have been proposed and implemented by various vendors in order to enhance the functionality of the base instruction set.
Timeline[edit]
| Extension | First µarch | Description | |
|---|---|---|---|
| 1978 | Real | 8086 | Original Real mode |
| 1982 | Protected | 80286 | Protected mode |
| 1985 | SMM | 80386 | System Management Mode |
| 1989 | FPU | 80486 | Incorporates the x87 FPU into the same die |
| 1996 | MMX | P5 | First implementation for SIMD instructions |
| 1998 | 3DNow! | K6-2 | SIMD extension for manipulating single-precision floating point |
| 1999 | SSE | P5 | Streaming SIMD Extensions, SIMD for single-precision floating point |
| 1999 | E3DNow! | K7 | Extended 3DNow! (New DSP instructions + some MMX instructions) |
| 1999 | Professional 3DNow! | A name given by AMD for E3DNow! + SSE | |
| 1999 | EMMX | P6 | Extended MMX; an extension to MMX |
| 2001 | SSE2 | P6 | Attempt to replace the original MMX instructions; wider XMM registers offer better performance |
| 2004 | SSE3 | Core | Streaming SIMD Extensions 3; new instructions to operate on multiple values in the same register |
| 2006 | SSSE3 | Core | Supplemental Streaming SIMD Extensions 3; additional instructions for working with packed integers |
| 2007 | SSE4.1 | Penryn | Streaming SIMD Extensions 4.1; initial set of instructions for manipulating media data |
| 2007 | SSE4a | K10 | 4 SIMD instructions, not related to 4.1/4.2 |
| 2007 | ABM | K10 | Advanced Bit Manipulation; bit counting instructions |
| 2008 | SSE4.2 | Nehalem | Streaming SIMD Extensions 4.2; second set of instructions for manipulating media data |
| 2007 | SSE5 | Proposed by AMD in 2007 but was never implemented | |
| 2008 | SSE4 | Streaming SIMD Extensions 4; Another name for SSE4.1 + SSE4.2 | |
| 2010 | CLMUL | Westmere | Carry-less multiplication of two registers |
| 2011 | AVX | Sandy Bridge | Advanced Vector Extensions; introduces 256-bits integer operations |
| 2012 | F16C | Ivy Bridge | Extension for performing half-precision <-> single-precision conversions |
| 2011 | XOP | Bulldozer | eXtended Operations; various vector operations |
| 2011 | FMA4 | Bulldozer | 4-operands fused multiply-add |
| 2011 | LWP | Bulldozer | Lightweight Profiling |
| 2011 | SMX | Nehalem | Safer Mode Extensions; instructions needed to facilitate trust decisions (Part of Intel's Trusted Execution Technology) |
| 2011 | AES | Westmere | Instructions for optimizing AES operations |
| 2012 | TBM | Piledriver | Trailing Bit Manipulation; bit manipulation instructions designed to be compiler intrinsics |
| 2013 | BMI1 | Jaguar | Bit Manipulation Instruction Set 1; introduces a number of bit manipulation instructions |
| 2013 | BMI2 | Haswell | Bit Manipulation Instruction Set 2; introduces additional bit manipulation instructions |
| 2013 | FMA3 | Haswell | 3-operands fused multiply-add |
| 2013 | TSX | Haswell | Transactional Synchronization Extensions; adds transactional memory support |
| 2013 | AVX2 | Haswell | Advanced Vector Extensions; additional instructions |
| 2014 | ADX | Broadwell | Multi-Precision Add-Carry Instruction extension |
| 2014 | RdRand | Broadwell | Part of Secure Key Technology extension (RdRand, RDSEED) |
| 2014 | PREFETCH | Broadwell | PREFETCH instructions (previously part of 3DNow!) |
| 2015 | AVX-512 | Airmont | 512 bit register operations |
| 2015 | MPX | Skylake | Memory Protection Extensions |
| 2015 | SGX | Skylake | Software Guard Extensions |
| 2016 | SHA | Goldmont | SHA Extensions |
| 2017 | SME | Zen | Secure Memory Extensions |
| 2019 | TME | Ice Lake | Total Memory Encryption |
Experimental Extensions[edit]
| Extension | First µarch | Description | |
|---|---|---|---|
| 2008 | L1OM | Larrabee | 512-bit vector extension |
| 2010 | K1OM | Knights Corner | 512-bit vector extension |
Backwards compatibility[edit]
Generally speaking, all extensions are supported from their introductory date to present day. Extensions introduced by AMD's K6-2 (i.e., 3DNow! & E3DNow!) and those introduced by AMD's Bulldozer (i.e., FMA4, XOP, LWP, and later TBM) have been obsoleted. Note that Zen, at least for first stepping, still offered FMA4 support even though it's not indicated by CPUID.