# x86-64 Extensions

[x86-64 Documentation](https://asm-editor.specy.app/documentation/x86.md)

Web page: https://asm-editor.specy.app/documentation/x86/extensions

Extension mnemonics grouped under NASM’s headings, with a short summary.

89 entries, each with its own page of markdown:

- [Other instructions](https://asm-editor.specy.app/documentation/x86/extensions/other-instructions.md): Use the entries below to find an instruction by mnemonic or by the NASM heading that groups it.
- [AMD Enhanced 3DNow! (Athlon) instructions](https://asm-editor.specy.app/documentation/x86/extensions/amd-enhanced-3dnow-athlon-instructions.md) `5 instructions`: pf2iw, pfnacc, pfpnacc, pi2fw, pswapd
- [AMD Lightweight Profiling (LWP) instructions](https://asm-editor.specy.app/documentation/x86/extensions/amd-lightweight-profiling-lwp-instructions.md) `4 instructions`: llwpcb, lwpins, lwpval, slwpcb
- [AMD SSE4A](https://asm-editor.specy.app/documentation/x86/extensions/amd-sse4a.md) `4 instructions`: extrq, insertq, movntsd, movntss
- [AMD XOP and FMA4 instructions (SSE5)](https://asm-editor.specy.app/documentation/x86/extensions/amd-xop-and-fma4-instructions-sse5.md) `73 instructions`: vfmaddpd, vfmaddps, vfmaddsd, vfmaddss and 69 more
- [AMD XOP bit operations](https://asm-editor.specy.app/documentation/x86/extensions/amd-xop-bit-operations.md) `9 instructions`: blcfill, blci, blcic, blcmsk and 5 more
- [AVX no exception conversions](https://asm-editor.specy.app/documentation/x86/extensions/avx-no-exception-conversions.md) `7 instructions`: vbcstnebf162ps, vbcstnebf16ps, vbcstnesh2ps, vcvtneebf162ps and 3 more
- [AVX-512 instructions](https://asm-editor.specy.app/documentation/x86/extensions/avx-512-instructions.md) `605 instructions`: vaddpd, vaddps, valignd, valignq and 601 more
- [AVX-512 mask register instructions](https://asm-editor.specy.app/documentation/x86/extensions/avx-512-mask-register-instructions.md) `140 instructions`: addb, addd, addq, addw and 136 more
- [AVX10.2 BF16 instructions](https://asm-editor.specy.app/documentation/x86/extensions/avx102-bf16-instructions.md) `29 instructions`: vaddbf16, vcmpbf16, vcomisbf16, vdivbf16 and 25 more
- [AVX10.2 Compare scalar fp with enhanced eflags instructions](https://asm-editor.specy.app/documentation/x86/extensions/avx102-compare-scalar-fp-with-enhanced-eflags-instructions.md) `6 instructions`: vcomxsd, vcomxsh, vcomxss, vucomxsd and 2 more
- [AVX10.2 Convert instructions](https://asm-editor.specy.app/documentation/x86/extensions/avx102-convert-instructions.md) `14 instructions`: vcvt2ph2bf8, vcvt2ph2bf8s, vcvt2ph2hf8, vcvt2ph2hf8s and 10 more
- [AVX10.2 Integer and FP16 VNNI, media new instructions](https://asm-editor.specy.app/documentation/x86/extensions/avx102-integer-and-fp16-vnni-media-new-instructions.md) `14 instructions`: vdpphps, vmpsadbw, vpdpbssd, vpdpbssds and 10 more
- [AVX10.2 MINMAX instructions](https://asm-editor.specy.app/documentation/x86/extensions/avx102-minmax-instructions.md) `7 instructions`: vminmaxbf16, vminmaxpd, vminmaxph, vminmaxps and 3 more
- [AVX10.2 Saturating convert instructions](https://asm-editor.specy.app/documentation/x86/extensions/avx102-saturating-convert-instructions.md) `24 instructions`: vcvtbf162ibs, vcvtbf162iubs, vcvtph2ibs, vcvtph2iubs and 20 more
- [AVX512 4-iteration Dot Product](https://asm-editor.specy.app/documentation/x86/extensions/avx512-4-iteration-dot-product.md) `2 instructions`: v4dpwssd, v4dpwssds
- [AVX512 4-iteration Multiply-Add](https://asm-editor.specy.app/documentation/x86/extensions/avx512-4-iteration-multiply-add.md) `4 instructions`: v4fmaddps, v4fmaddss, v4fnmaddps, v4fnmaddss
- [AVX512 Bfloat16 instructions](https://asm-editor.specy.app/documentation/x86/extensions/avx512-bfloat16-instructions.md) `3 instructions`: vcvtne2ps2bf16, vcvtneps2bf16, vdpbf16ps
- [AVX512 Bit Algorithms](https://asm-editor.specy.app/documentation/x86/extensions/avx512-bit-algorithms.md) `5 instructions`: vpopcntb, vpopcntd, vpopcntq, vpopcntw, vpshufbitqmb
- [AVX512 mask intersect instructions](https://asm-editor.specy.app/documentation/x86/extensions/avx512-mask-intersect-instructions.md) `2 instructions`: vp2intersectd, vp2intersectq
- [AVX512 Vector Bit Manipulation Instructions 2](https://asm-editor.specy.app/documentation/x86/extensions/avx512-vector-bit-manipulation-instructions-2.md) `16 instructions`: vpcompressb, vpcompressw, vpexpandb, vpexpandw and 12 more
- [AVX512 VNNI](https://asm-editor.specy.app/documentation/x86/extensions/avx512-vnni.md) `4 instructions`: vpdpbusd, vpdpbusds, vpdpwssd, vpdpwssds
- [BMI1 and BMI2 bit operations](https://asm-editor.specy.app/documentation/x86/extensions/bmi1-and-bmi2-bit-operations.md) `10 instructions`: andn, bextr, blsi, blsmsk and 6 more
- [Conditional instructions (extensions)](https://asm-editor.specy.app/documentation/x86/extensions/conditional-instructions-extensions.md) `90 instructions`: cfcmova, cfcmovae, cfcmovb, cfcmovbe and 86 more
- [doc 319433-034 May 2018](https://asm-editor.specy.app/documentation/x86/extensions/doc-319433-034-may-2018.md) `4 instructions`: cldemote, movdir64b, movdiri, pconfig
- [doc 319433-058 June 2025](https://asm-editor.specy.app/documentation/x86/extensions/doc-319433-058-june-2025.md) `2 instructions`: pbndkb, prefetchrst2
- [Extended Page Tables VMX instructions](https://asm-editor.specy.app/documentation/x86/extensions/extended-page-tables-vmx-instructions.md) `2 instructions`: invept, invvpid
- [Flag register instructions (extensions)](https://asm-editor.specy.app/documentation/x86/extensions/flag-register-instructions-extensions.md) `2 instructions`: clac, stac
- [Galois field operations (GFNI)](https://asm-editor.specy.app/documentation/x86/extensions/galois-field-operations-gfni.md) `6 instructions`: gf2p8affineinvqb, gf2p8affineqb, gf2p8mulb, vgf2p8affineinvqb and 2 more
- [Generic memory operations](https://asm-editor.specy.app/documentation/x86/extensions/generic-memory-operations.md) `6 instructions`: prefetchit0, prefetchit1, prefetchnta, prefetcht0 and 2 more
- [Geode (Cyrix) 3DNow! additions](https://asm-editor.specy.app/documentation/x86/extensions/geode-cyrix-3dnow-additions.md) `2 instructions`: pfrcpv, pfrsqrtv
- [History reset](https://asm-editor.specy.app/documentation/x86/extensions/history-reset.md) `1 instruction`: hreset
- [I/O instructions](https://asm-editor.specy.app/documentation/x86/extensions/io-instructions.md) `2 instructions`: in, out
- [Instructions from ISE doc 319433-040, June 2020](https://asm-editor.specy.app/documentation/x86/extensions/instructions-from-ise-doc-319433-040-june-2020.md) `4 instructions`: enqcmd, enqcmds, xresldtrk, xsusldtrk
- [Intel Advanced Matrix Extensions (AMX)](https://asm-editor.specy.app/documentation/x86/extensions/intel-advanced-matrix-extensions-amx.md) `44 instructions`: ldtilecfg, sttilecfg, t2rpntlvwz0, t2rpntlvwz0rs and 40 more
- [Intel AES instructions](https://asm-editor.specy.app/documentation/x86/extensions/intel-aes-instructions.md) `6 instructions`: aesdec, aesdeclast, aesenc, aesenclast and 2 more
- [Intel AES Key Locker](https://asm-editor.specy.app/documentation/x86/extensions/intel-aes-key-locker.md) `11 instructions`: aesdec128kl, aesdec256kl, aesdecwide128kl, aesdecwide256kl and 7 more
- [Intel AVX AES instructions](https://asm-editor.specy.app/documentation/x86/extensions/intel-avx-aes-instructions.md) `2 instructions`: vaesimc, vaeskeygenassist
- [Intel AVX Carry-Less Multiplication instructions (CLMUL)](https://asm-editor.specy.app/documentation/x86/extensions/intel-avx-carry-less-multiplication-instructions-clmul.md) `21 instructions`: vfcmulcph, vfmadd132sh, vfmadd213sh, vfmadd231sh and 17 more
- [Intel AVX instructions](https://asm-editor.specy.app/documentation/x86/extensions/intel-avx-instructions.md) `204 instructions`: vaddsd, vaddss, vaddsubpd, vaddsubps and 200 more
- [Intel AVX2 instructions](https://asm-editor.specy.app/documentation/x86/extensions/intel-avx2-instructions.md) `7 instructions`: vbroadcasti128, vextracti128, vinserti128, vpblendd and 3 more
- [Intel AVX512-FP16 instructions](https://asm-editor.specy.app/documentation/x86/extensions/intel-avx512-fp16-instructions.md) `114 instructions`: vaddph, vaddsh, vcmpph, vcmpsh and 110 more
- [Intel Carry-Less Multiplication instructions (CLMUL)](https://asm-editor.specy.app/documentation/x86/extensions/intel-carry-less-multiplication-instructions-clmul.md) `5 instructions`: pclmulhqhqdq, pclmulhqlqdq, pclmullqhqdq, pclmullqlqdq, pclmulqdq
- [Intel Control-Flow Enforcement Technology (CET)](https://asm-editor.specy.app/documentation/x86/extensions/intel-control-flow-enforcement-technology-cet.md) `14 instructions`: clrssbsy, endbr32, endbr64, incsspd and 10 more
- [Intel Fused Multiply-Add instructions (FMA)](https://asm-editor.specy.app/documentation/x86/extensions/intel-fused-multiply-add-instructions-fma.md) `84 instructions`: vfmadd123pd, vfmadd123ps, vfmadd123sd, vfmadd123ss and 80 more
- [Intel instruction extension based on pub number 319433-030 dated October 2017](https://asm-editor.specy.app/documentation/x86/extensions/intel-instruction-extension-based-on-pub-number-319433-030-dated-october-2017.md) `4 instructions`: vaesdec, vaesdeclast, vaesenc, vaesenclast
- [Intel Memory Protection Extensions (MPX)](https://asm-editor.specy.app/documentation/x86/extensions/intel-memory-protection-extensions-mpx.md) `7 instructions`: bndcl, bndcn, bndcu, bndldx and 3 more
- [Intel memory protection keys for userspace (PKU aka PKEYs)](https://asm-editor.specy.app/documentation/x86/extensions/intel-memory-protection-keys-for-userspace-pku-aka-pkeys.md) `2 instructions`: rdpkru, wrpkru
- [Intel SHA acceleration instructions](https://asm-editor.specy.app/documentation/x86/extensions/intel-sha-acceleration-instructions.md) `10 instructions`: sha1msg1, sha1msg2, sha1nexte, sha1rnds4 and 6 more
- [Intel SMX](https://asm-editor.specy.app/documentation/x86/extensions/intel-smx.md) `1 instruction`: getsec
- [Intel Software Guard Extensions (SGX)](https://asm-editor.specy.app/documentation/x86/extensions/intel-software-guard-extensions-sgx.md) `3 instructions`: encls, enclu, enclv
- [Intel Transactional Synchronization Extensions (TSX)](https://asm-editor.specy.app/documentation/x86/extensions/intel-transactional-synchronization-extensions-tsx.md) `5 instructions`: prefetchwt1, xabort, xbegin, xend, xtest
- [Interleaved flags arithmetic](https://asm-editor.specy.app/documentation/x86/extensions/interleaved-flags-arithmetic.md) `2 instructions`: adcx, adox
- [Interrupts, system calls, and returns (extensions)](https://asm-editor.specy.app/documentation/x86/extensions/interrupts-system-calls-and-returns-extensions.md) `2 instructions`: erets, eretu
- [Introduced in Deschutes but necessary for SSE support](https://asm-editor.specy.app/documentation/x86/extensions/introduced-in-deschutes-but-necessary-for-sse-support.md) `4 instructions`: fxrstor, fxrstor64, fxsave, fxsave64
- [Jumps (extensions)](https://asm-editor.specy.app/documentation/x86/extensions/jumps-extensions.md) `1 instruction`: jmpabs
- [Katmai Streaming SIMD instructions (SSE -- a.k.a. KNI, XMM, MMX2)](https://asm-editor.specy.app/documentation/x86/extensions/katmai-streaming-simd-instructions-sse-aka-kni-xmm-mmx2.md) `62 instructions`: addps, addss, andnps, andps and 58 more
- [Machine control and management instructions](https://asm-editor.specy.app/documentation/x86/extensions/machine-control-and-management-instructions.md) `20 instructions`: bb0_reset, bb1_reset, clts, cpu_read and 16 more
- [Memory management and control](https://asm-editor.specy.app/documentation/x86/extensions/memory-management-and-control.md) `11 instructions`: clflush, clflushopt, clwb, clzero and 7 more
- [MMX (SIMD using the x87 register file)](https://asm-editor.specy.app/documentation/x86/extensions/mmx-simd-using-the-x87-register-file.md) `78 instructions`: emms, movd, packssdw, packsswb and 74 more
- [MMX instructions](https://asm-editor.specy.app/documentation/x86/extensions/mmx-instructions.md) `2 instructions`: pxor, skinit
- [Nehalem New Instructions (SSE4.2)](https://asm-editor.specy.app/documentation/x86/extensions/nehalem-new-instructions-sse42.md) `7 instructions`: crc32, pcmpestri, pcmpestrm, pcmpgtq and 3 more
- [New MMX instructions introduced in Katmai](https://asm-editor.specy.app/documentation/x86/extensions/new-mmx-instructions-introduced-in-katmai.md) `12 instructions`: maskmovq, movntq, pavgb, pavgw and 8 more
- [Other basic integer arithmetic (extensions)](https://asm-editor.specy.app/documentation/x86/extensions/other-basic-integer-arithmetic-extensions.md) `1 instruction`: mulx
- [Penryn New Instructions (SSE4.1)](https://asm-editor.specy.app/documentation/x86/extensions/penryn-new-instructions-sse41.md) `49 instructions`: blendpd, blendps, blendvpd, blendvps and 45 more
- [Permanently undefined instructions](https://asm-editor.specy.app/documentation/x86/extensions/permanently-undefined-instructions.md) `67 instructions`: ccmp, ccmpa, ccmpae, ccmpb and 63 more
- [Power management](https://asm-editor.specy.app/documentation/x86/extensions/power-management.md) `12 instructions`: hlt, monitor, monitord, monitorq and 8 more
- [Prescott New Instructions (SSE3)](https://asm-editor.specy.app/documentation/x86/extensions/prescott-new-instructions-sse3.md) `10 instructions`: addsubpd, addsubps, haddpd, haddps and 6 more
- [Processor trace write](https://asm-editor.specy.app/documentation/x86/extensions/processor-trace-write.md) `1 instruction`: ptwrite
- [RAO-INT weakly ordered atomic operations](https://asm-editor.specy.app/documentation/x86/extensions/rao-int-weakly-ordered-atomic-operations.md) `4 instructions`: aadd, aand, aor, axor
- [S3M hash instructions](https://asm-editor.specy.app/documentation/x86/extensions/s3m-hash-instructions.md) `3 instructions`: vsm3msg1, vsm3msg2, vsm3rnds2
- [Segment handling instructions](https://asm-editor.specy.app/documentation/x86/extensions/segment-handling-instructions.md) `26 instructions`: arpl, lar, lds, les and 22 more
- [SEV-SNP AMD instructions](https://asm-editor.specy.app/documentation/x86/extensions/sev-snp-amd-instructions.md) `3 instructions`: pvalidate, rmpadjust, vmgexit
- [SM4 hash instructions](https://asm-editor.specy.app/documentation/x86/extensions/sm4-hash-instructions.md) `2 instructions`: vsm4key4, vsm4rnds4
- [Special reads: timestamp, CPU number, performance counters, randomness](https://asm-editor.specy.app/documentation/x86/extensions/special-reads-timestamp-cpu-number-performance-counters-randomness.md) `6 instructions`: rdpid, rdpmc, rdrand, rdseed and 2 more
- [Stack operations (extensions)](https://asm-editor.specy.app/documentation/x86/extensions/stack-operations-extensions.md) `6 instructions`: pop2, pop2p, popp, push2 and 2 more
- [Synchronization and fencing](https://asm-editor.specy.app/documentation/x86/extensions/synchronization-and-fencing.md) `4 instructions`: lfence, mfence, serialize, sfence
- [System management mode](https://asm-editor.specy.app/documentation/x86/extensions/system-management-mode.md) `9 instructions`: rdshr, rsdc, rsldt, rsm and 5 more
- [Systematic names for the hinting nop instructions](https://asm-editor.specy.app/documentation/x86/extensions/systematic-names-for-the-hinting-nop-instructions.md) `65 instructions`: hint_nop, hint_nop0, hint_nop1, hint_nop10 and 61 more
- [Tejas New Instructions (SSSE3)](https://asm-editor.specy.app/documentation/x86/extensions/tejas-new-instructions-ssse3.md) `16 instructions`: pabsb, pabsd, pabsw, palignr and 12 more
- [The basic shift and rotate operations (extensions)](https://asm-editor.specy.app/documentation/x86/extensions/the-basic-shift-and-rotate-operations-extensions.md) `6 instructions`: rolx, rorx, salx, sarx and 2 more
- [User interrupts](https://asm-editor.specy.app/documentation/x86/extensions/user-interrupts.md) `5 instructions`: clui, senduipi, stui, testui, uiret
- [VIA (Centaur) security instructions](https://asm-editor.specy.app/documentation/x86/extensions/via-centaur-security-instructions.md) `9 instructions`: montmul, xcryptcbc, xcryptcfb, xcryptctr and 5 more
- [VMX/SVM Instructions](https://asm-editor.specy.app/documentation/x86/extensions/vmxsvm-instructions.md) `17 instructions`: clgi, stgi, vmcall, vmclear and 13 more
- [Willamette MMX instructions (SSE2 SIMD Integer Instructions)](https://asm-editor.specy.app/documentation/x86/extensions/willamette-mmx-instructions-sse2-simd-integer-instructions.md) `16 instructions`: movdq2q, movdqa, movdqu, movq and 12 more
- [Willamette SSE2 Cacheability Instructions](https://asm-editor.specy.app/documentation/x86/extensions/willamette-sse2-cacheability-instructions.md) `4 instructions`: maskmovdqu, movntdq, movnti, movntpd
- [Willamette Streaming SIMD instructions (SSE2)](https://asm-editor.specy.app/documentation/x86/extensions/willamette-streaming-simd-instructions-sse2.md) `62 instructions`: addpd, addsd, andnpd, andpd and 58 more
- [x87 floating point](https://asm-editor.specy.app/documentation/x86/extensions/x87-floating-point.md) `99 instructions`: f2xm1, fabs, fadd, faddp and 95 more
- [XSAVE group (AVX and extended state)](https://asm-editor.specy.app/documentation/x86/extensions/xsave-group-avx-and-extended-state.md) `14 instructions`: xgetbv, xrstor, xrstor64, xrstors and 10 more