AVX-512
AVX-512 are 512-bit extensions to the 256-bit Advanced Vector Extensions SIMD instructions for x86 instruction set architecture proposed by Intel in July 2013, and implemented in Intel's Xeon Phi x200 and Skylake-X CPUs; this includes the , as well as the new Xeon Scalable Processor Family and Xeon D-2100 Embedded Series.
AVX-512 is not the first 512-bit SIMD instruction set that Intel has introduced in processors: the earlier 512-bit SIMD instructions used in the first generation Xeon Phi coprocessors, derived from Intel's Larrabee project, are similar but not binary compatible and only partially source compatible.
AVX-512 consists of multiple extensions that may be implemented independently. This policy is a departure from the historical requirement of implementing the entire instruction block. Only the core extension AVX-512F is required by all AVX-512 implementations.
Instruction set
The AVX-512 instruction set consists of several separate sets each having their own unique CPUID feature bit; however, they are typically grouped by the processor generation that implements them.; F, CD, ER, PF: Introduced with Xeon Phi x200 and Xeon E5-26xx V5, with the last two being specific to Knights Landing.
; VL, DQ, BW: Introduced with Skylake X and Cannon Lake.
; IFMA, VBMI: Introduced with Cannon Lake.
; 4VNNIW, 4FMAPS:Introduced with Knights Mill.
; VPOPCNTDQ: Vector population count instruction. Introduced with Knights Mill and Ice Lake.
; VNNI, VBMI2, BITALG:Introduced with Ice Lake.
; VP2INTERSECT: Introduced with Tiger Lake.
; GFNI, VPCLMULQDQ, VAES:Introduced with Ice Lake.
Encoding and features
The VEX prefix used by AVX and AVX2, while flexible, did not leave enough room for the features Intel wanted to add to AVX-512. This has led them to define a new prefix called EVEX.Compared to VEX, EVEX adds the following benefits:
- Expanded register encoding allowing 32 512-bit registers.
- Adds 8 new opmask registers for masking most AVX-512 instructions.
- Adds a new scalar memory mode that automatically performs a broadcast.
- Adds room for explicit rounding control in each instruction.
- Adds a new compressed displacement memory addressing mode.
SIMD modes
The AVX-512 instructions are designed to mix with 128/256-bit AVX/AVX2 instructions without a performance penalty. However, AVX-512VL extensions allows the use of AVX-512 instructions on 128/256-bit registers XMM/YMM, so most SSE and AVX/AVX2 instructions have new AVX-512 versions encoded with the EVEX prefix which allow access to new features such as opmask and additional registers. Unlike AVX-256, the new instructions do not have new mnemonics but share namespace with AVX, making the distinction between VEX and EVEX encoded versions of an instruction ambiguous in the source code. Since AVX-512F only works on 32- and 64-bit values, SSE and AVX/AVX2 instructions that operate on bytes or words are available only with the AVX-512BW extension.| Name | Extension sets | Registers | Types |
| Legacy SSE | SSE-SSE4.2 | xmm0-xmm15 | single floats. From SSE2: bytes, words, doublewords, quadwords and double floats. |
| AVX-128 | AVX, AVX2 | xmm0-xmm15 | bytes, words, doublewords, quadwords, single floats and double floats. |
| AVX-256 | AVX, AVX2 | ymm0-ymm15 | single float and double float. From AVX2: bytes, words, doublewords, quadwords |
| AVX-128 | AVX-512VL | xmm0-xmm31 | doublewords, quadwords, single float and double float. With AVX512BW: bytes and words |
| AVX-256 | AVX-512VL | ymm0-ymm31 | doublewords, quadwords, single float and double float. With AVX512BW: bytes and words |
| AVX-512 | AVX-512F | zmm0-zmm31 | doublewords, quadwords, single float and double float. With AVX512BW: bytes and words |
Extended registers
The width of the SIMD register file is increased from 256 bits to 512 bits, and expanded from 16 to a total of 32 registers ZMM0-ZMM31. These registers can be addressed as 256 bit YMM registers from AVX extensions and 128-bit XMM registers from Streaming SIMD Extensions, and legacy AVX and SSE instructions can be extended to operate on the 16 additional registers XMM16-XMM31 and YMM16-YMM31 when using EVEX encoded form.Opmask registers
Most AVX-512 instructions may indicate one of 8 opmask registers. For instructions which use a mask register as an opmask, register `k0` is special: a hardcoded constant used to indicate unmasked operations. For other operations, such as those that write to an opmask register or perform arithmetic or logical operations, `k0` is a functioning, valid register. In most instructions, the opmask is used to control which values are written to the destination. A flag controls the opmask behavior, which can either be "zero", which zeros everything not selected by the mask, or "merge", which leaves everything not selected untouched. The merge behavior is identical to the blend instructions.The opmask registers are normally 16 bits wide, but can be up to 64 bits with the AVX-512BW extension. How many of the bits are actually used, though, depends on the vector type of the instructions masked. For the 32-bit single float or double words, 16 bits are used to mask the 16 elements in a 512-bit register. For double float and quad words, at most 8 mask bits are used.
The opmask register is the reason why several bitwise instructions which naturally have no element widths had them added in AVX-512. For instance, bitwise AND, OR or 128-bit shuffle now exist in both double-word and quad-word variants with the only difference being in the final masking.
New opmask instructions
The opmask registers have a new mini extension of instructions operating directly on them. Unlike the rest of the AVX-512 instructions, these instructions are all VEX encoded. The initial opmask instructions are all 16-bit versions. With AVX-512DQ 8-bit versions were added to better match the needs of masking 8 64-bit values, and with AVX-512BW 32-bit and 64-bit versions were added so they can mask up to 64 8-bit values. The instructions KORTEST and KTEST can be used to set the x86 flags based on mask registers, so that they may be used together with non-SIMD x86 branch and conditional instructions.| Instruction | Extension set | Description |
KAND | F | Bitwise logical AND Masks |
KANDN | F | Bitwise logical AND NOT Masks |
KMOV | F | Move from and to Mask Registers or General Purpose Registers |
KUNPCK | F | Unpack for Mask Registers |
KNOT | F | NOT Mask Register |
KOR | F | Bitwise logical OR Masks |
KORTEST | F | OR Masks And Set Flags |
KSHIFTL | F | Shift Left Mask Registers |
KSHIFTR | F | Shift Right Mask Registers |
KXNOR | F | Bitwise logical XNOR Masks |
KXOR | F | Bitwise logical XOR Masks |
KADD | BW/DQ | Add Two Masks |
KTEST | BW/DQ | Bitwise comparison and set flags |
New instructions in AVX-512 foundation
Many AVX-512 instructions are simply EVEX versions of old SSE or AVX instructions. There are, however, several new instructions, and old instructions that have been replaced with new AVX-512 versions. The new or majorly reworked instructions are listed below. These foundation instructions also include the extensions from AVX-512VL and AVX-512BW since those extensions merely add new versions of these instructions instead of new instructions.Blend using mask
There are no EVEX-prefixed versions of the blend instructions from SSE4; instead, AVX-512 has a new set of blending instructions using mask registers as selectors. Together with the general compare into mask instructions below, these may be used to implement generic ternary operations or cmov, similar to XOP's VPCMOV.Since blending is an integral part of the EVEX encoding, these instruction may also be considered basic move instructions. Using the zeroing blend mode, they can also be used as masking instructions.
| Instruction | Extension set | Description |
VBLENDMPD | F | Blend float64 vectors using opmask control |
VBLENDMPS | F | Blend float32 vectors using opmask control |
VPBLENDMD | F | Blend int32 vectors using opmask control |
VPBLENDMQ | F | Blend int64 vectors using opmask control |
VPBLENDMB | BW | Blend byte integer vectors using opmask control |
VPBLENDMW | BW | Blend word integer vectors using opmask control |
Compare into mask
AVX-512F has four new compare instructions. Like their XOP counterparts they use the immediate field to select between 8 different comparisons. Unlike their XOP inspiration, however, they save the result to a mask register and initially only support doubleword and quadword comparisons. The AVX-512BW extension provides the byte and word versions. Note that two mask registers may be specified for the instructions, one to write to and one to declare regular masking.| Immediate | Comparison | Description |
| 0 | EQ | Equal |
| 1 | LT | Less than |
| 2 | LE | Less than or equal |
| 3 | FALSE | Set to zero |
| 4 | NEQ | Not equal |
| 5 | NLT | Greater than or equal |
| 6 | NLE | Greater than |
| 7 | TRUE | Set to one |
| Instruction | Extension set | Description |
VPCMPDVPCMPUD | F | Compare signed/unsigned doublewords into mask |
VPCMPQVPCMPUQ | F | Compare signed/unsigned quadwords into mask |
VPCMPBVPCMPUB | BW | Compare signed/unsigned bytes into mask |
VPCMPWVPCMPUW | BW | Compare signed/unsigned words into mask |
Logical set mask
The final way to set masks is using Logical Set Mask. These instructions perform either AND or NAND, and then set the destination opmask based on the result values being zero or non-zero. Note that like the comparison instructions, these take two opmask registers, one as destination and one a regular opmask.| Instruction | Extension set | Description |
VPTESTMD, VPTESTMQ | F | Logical AND and set mask for 32 or 64 bit integers. |
VPTESTNMD, VPTESTNMQ | F | Logical NAND and set mask for 32 or 64 bit integers. |
VPTESTMB, VPTESTMW | BW | Logical AND and set mask for 8 or 16 bit integers. |
VPTESTNMB, VPTESTNMW | BW | Logical NAND and set mask for 8 or 16 bit integers. |
Compress and expand
The compress and expand instructions match the APL operations of the same name. They use the opmask in a slightly different way from other AVX-512 instructions. Compress only saves the values marked in the mask, but saves them compacted by skipping and not reserving space for unmarked values. Expand operates in the opposite way, by loading as many values as indicated in the mask and then spreading them to the selected positions.| Instruction | Description |
VCOMPRESSPD,VCOMPRESSPS | Store sparse packed double/single-precision floating-point values into dense memory |
VPCOMPRESSD,VPCOMPRESSQ | Store sparse packed doubleword/quadword integer values into dense memory/register |
VEXPANDPD,VEXPANDPS | Load sparse packed double/single-precision floating-point values from dense memory |
VPEXPANDD,VPEXPANDQ | Load sparse packed doubleword/quadword integer values from dense memory/register |
Permute
A new set of permute instructions have been added for full two input permutations. They all take three arguments, two source registers and one index; the result is output by either overwriting the first source register or the index register. AVX-512BW extends the instructions to also include 16-bit versions, and the AVX-512_VBMI extension defines the byte versions of the instructions.| Instruction | Extension set | Description |
VPERMB | VBMI | Permute packed bytes elements. |
VPERMW | BW | Permute packed words elements. |
VPERMT2B | VBMI | Full byte permute overwriting first source. |
VPERMT2W | BW | Full word permute overwriting first source. |
VPERMI2PD, VPERMI2PS | F | Full single/double floating point permute overwriting the index. |
VPERMI2D, VPERMI2Q | F | Full doubleword/quadword permute overwriting the index. |
VPERMI2B | VBMI | Full byte permute overwriting the index. |
VPERMI2W | BW | Full word permute overwriting the index. |
VPERMT2PS, VPERMT2PD | F | Full single/double floating point permute overwriting first source. |
VPERMT2D, VPERMT2Q | F | Full doubleword/quadword permute overwriting first source. |
VSHUFF32x4, VSHUFF64x2,VSHUFFI32x4, VSHUFFI64x2 | F | Shuffle four packed 128-bit lines. |
VPMULTISHIFTQB | VBMI | Select packed unaligned bytes from quadword sources. |
Bitwise ternary logic
Two new instructions added can logically implement all possible bitwise operations between three inputs. They take three registers as input and an 8-bit immediate field. Each bit in the output is generated using a lookup of the three corresponding bits in the inputs to select one of the 8 positions in the 8-bit immediate. Since only 8 combinations are possible using three bits, this allow all possible 3 input bitwise operations to be performed.These are the only bitwise vector instructions in AVX-512F; EVEX versions of the two source SSE and AVX bitwise vector instructions AND, ANDN, OR and XOR were added in AVX-512DQ.
The difference in the doubleword and quadword versions is only the application of the opmask.
| Instruction | Description |
VPTERNLOGD, VPTERNLOGQ | Bitwise Ternary Logic |
Truth table:
| A0 | A1 | A2 | Double AND | Double OR | Bitwise blend |
| 0 | 0 | 0 | 0 | 0 | 0 |
| 0 | 0 | 1 | 0 | 1 | 1 |
| 0 | 1 | 0 | 0 | 1 | 0 |
| 0 | 1 | 1 | 0 | 1 | 1 |
| 1 | 0 | 0 | 0 | 1 | 0 |
| 1 | 0 | 1 | 0 | 1 | 0 |
| 1 | 1 | 0 | 0 | 1 | 1 |
| 1 | 1 | 1 | 1 | 1 | 1 |
Conversions
A number of conversion or move instructions were added; these complete the set of conversion instructions available from SSE2.| Instruction | Extension set | Description |
VPMOVQD, VPMOVSQD, VPMOVUSQD,VPMOVQW, VPMOVSQW,VPMOVUSQW,VPMOVQB, VPMOVSQB, VPMOVUSQB,VPMOVDW, VPMOVSDW, VPMOVUSDW,VPMOVDB, VPMOVSDB, VPMOVUSDB | F | Down convert quadword or doubleword to doubleword, word or byte; unsaturated, saturated or saturated unsigned. The reverse of the sign/zero extend instructions from SSE4.1. |
VPMOVWB, VPMOVSWB, VPMOVUSWB | BW | Down convert word to byte; unsaturated, saturated or saturated unsigned. |
VCVTPS2UDQ, VCVTPD2UDQ,VCVTTPS2UDQ, VCVTTPD2UDQ | F | Convert with or without truncation, packed single or double-precision floating point to packed unsigned doubleword integers. |
VCVTSS2USI , VCVTSD2USI , VCVTTSS2USI , VCVTTSD2USI | F | Convert with or without trunction, scalar single or double-precision floating point to unsigned doubleword integer. |
VCVTPS2QQ, VCVTPD2QQ,VCVTPS2UQQ, VCVTPD2UQQ,VCVTTPS2QQ, VCVTTPD2QQ,VCVTTPS2UQQ, VCVTTPD2UQQ | DQ | Convert with or without truncation, packed single or double-precision floating point to packed signed or unsigned quadword integers. |
VCVTUDQ2PS , VCVTUDQ2PD | F | Convert packed unsigned doubleword integers to packed single or double-precision floating point. |
VCVTUSI2PS , VCVTUSI2PD | F | Convert scalar unsigned doubleword integers to single or double-precision floating point. |
VCVTUSI2SD, VCVTUSI2SS | F | Convert scalar unsigned integers to single or double-precision floating point. |
VCVTUQQ2PS, VCVTUQQ2PD | DQ | Convert packed unsigned quadword integers to packed single or double-precision floating point. |
VCVTQQ2PD, VCVTQQ2PS | F | Convert packed quadword integers to packed single or double-precision floating point. |
Floating point decomposition
Among the unique new features in AVX-512F are instructions to decompose floating-point values and handle special floating-point values. Since these methods are completely new, they also exist in scalar versions.| Instruction | Description |
VGETEXPPD, VGETEXPPS | Convert exponents of packed fp values into fp values |
VGETEXPSD, VGETEXPSS | Convert exponent of scalar fp value into fp value |
VGETMANTPD, VGETMANTPS | Extract vector of normalized mantissas from float32/float64 vector |
VGETMANTSD, VGETMANTSS | Extract float32/float64 of normalized mantissa from float32/float64 scalar |
VFIXUPIMMPD, VFIXUPIMMPS | Fix up special packed float32/float64 values |
VFIXUPIMMSD, VFIXUPIMMSS | Fix up special scalar float32/float64 value |
Floating point arithmetic
This is the second set of new floating-point methods, which includes new scaling and approximate calculation of reciprocal, and reciprocal of square root. The approximate reciprocal instructions guarantee to have at most a relative error of 2−14.| Instruction | Description |
VRCP14PD, VRCP14PS | Compute approximate reciprocals of packed float32/float64 values |
VRCP14SD, VRCP14SS | Compute approximate reciprocals of scalar float32/float64 value |
VRNDSCALEPS, VRNDSCALEPD | Round packed float32/float64 values to include a given number of fraction bits |
VRNDSCALESS, VRNDSCALESD | Round scalar float32/float64 value to include a given number of fraction bits |
VRSQRT14PD, VRSQRT14PS | Compute approximate reciprocals of square roots of packed float32/float64 values |
VRSQRT14SD, VRSQRT14SS | Compute approximate reciprocal of square root of scalar float32/float64 value |
VSCALEFPS, VSCALEFPD | Scale packed float32/float64 values with float32/float64 values |
VSCALEFSS, VSCALEFSD | Scale scalar float32/float64 value with float32/float64 value |
Broadcast
Miscellaneous
New instructions by sets
Conflict detection
The instructions in AVX-512 conflict detection are designed to help efficiently calculate conflict-free subsets of elements in loops that normally could not be safely vectorized.| Instruction | Name | Description |
VPCONFLICTD, VPCONFLICTQ | Detect conflicts within vector of packed double- or quadwords values. | Compares each element in the first source, to all elements on same or earlier places in the second source and forms a bit vector of the results. |
VPLZCNTD, VPLZCNTQ | Count the number of leading zero bits for packed double- or quadword values. | Vectorized LZCNT instruction. |
VPBROADCASTMB2Q,VPBROADCASTMW2D | Broadcast mask to vector register. | Either 8-bit mask to quadword vector, or 16-bit mask to doubleword vector. |
Exponential and reciprocal
AVX-512 exponential and reciprocal instructions contain more accurate approximate reciprocal instructions than those in the AVX-512 foundation; relative error is at most 2−28. They also contain two new exponential functions that have a relative error of at most 2−23.| Instruction | Description |
VEXP2PD, VEXP2PS | Compute approximate exponential 2^x of packed single or double-precision floating point values |
VRCP28PD, VRCP28PS | Compute approximate reciprocals of packed single or double-precision floating point values |
VRCP28SD, VRCP28SS | Compute approximate reciprocal of scalar single or double-precision floating point value |
VRSQRT28PD, VRSQRT28PS | Compute approximate reciprocals of square roots of packed single or double-precision floating point values |
VRSQRT28SD, VRSQRT28SS | Compute approximate reciprocal of square root of scalar single or double-precision floating point value |
Prefetch
AVX-512 prefetch instructions contain new prefetch operations for the new scatter and gather functionality introduced in AVX2 and AVX-512.T0 prefetch means prefetching into level 1 cache and T1 means prefetching into level 2 cache.| Instruction | Description |
VGATHERPF0DPS, VGATHERPF0QPS, VGATHERPF0DPD, VGATHERPF0QPD | Using signed dword/qword indices, prefetch sparse byte memory locations containing single/double-precision data using opmask k1 and T0 hint. |
VGATHERPF1DPS, VGATHERPF1QPS, VGATHERPF1DPD, VGATHERPF1QPD | Using signed dword/qword indices, prefetch sparse byte memory locations containing single/double-precision data using opmask k1 and T1 hint. |
VSCATTERPF0DPS, VSCATTERPF0QPS, VSCATTERPF0DPD, VSCATTERPF0QPD | Using signed dword/qword indices, prefetch sparse byte memory locations containing single/double-precision data using writemask k1 and T0 hint with intent to write. |
VSCATTERPF1DPS, VSCATTERPF1QPS, VSCATTERPF1DPD, VSCATTERPF1QPD | Using signed dword/qword indices, prefetch sparse byte memory locations containing single/double precision data using writemask k1 and T1 hint with intent to write. |
4FMAPS and 4VNNIW
BW, DQ and VBMI
AVX-512DQ adds new doubleword and quadword instructions. AVX-512BW adds byte and words versions of the same instructions, and adds byte and word version of doubleword/quadword instructions in AVX-512F. A few instructions which get only word forms with AVX-512BW acquire byte forms with the AVX-512_VBMI extension.Two new instructions were added to the mask instructions set:
KADD and KTEST. The rest of mask instructions, which had only word forms, got byte forms with AVX-512DQ and doubleword/quadword forms with AVX-512BW. KUNPCKBW was extended to KUNPCKWD and KUNPCKDQ by AVX-512BW.Among the instructions added by AVX-512DQ are several SSE, AVX instruction that didn't get AVX-512 versions with AVX-512F, among those are all the two input bitwise instructions and extract/insert integer instructions.
Instructions that are completely new are covered below.
Floating point instructions
Three new floating point operations are introduced. Since they are not only new to AVX-512 they have both packed/SIMD and scalar versions.The
VFPCLASS instructions tests if the floating point value is one of eight special floating-point values, which of the eight values will trigger a bit in the output mask register is controlled by the immediate field. The VRANGE instructions perform minimum or maximum operations depending on the value of the immediate field, which can also control if the operation is done absolute or not and separately how the sign is handled. The VREDUCE instructions operate on a single source, and subtract from that the integer part of the source value plus a number of bits specified in the immediate field of its fraction.| Instruction | Extension set | Description |
VFPCLASSPS, VFPCLASSPD | DQ | Test types of packed single and double precision floating point values. |
VFPCLASSSS, VFPCLASSSD | DQ | Test types of scalar single and double precision floating point values. |
VRANGEPS, VRANGEPD | DQ | Range restriction calculation for packed floating point values. |
VRANGESS, VRANGESD | DQ | Range restriction calculation for scalar floating point values. |
VREDUCEPS, VREDUCEPD | DQ | Perform reduction transformation on packed floating point values. |
VREDUCESS, VREDUCESD | DQ | Perform reduction transformation on scalar floating point values. |
Other instructions
VBMI2
Extend VPCOMPRESS and VPEXPAND with byte and word variants. Shift instructions are new.| Instruction | Description |
VPCOMPRESSB, VPCOMPRESSW | Store sparse packed byte/word integer values into dense memory/register |
VPEXPANDB, VPEXPANDW | Load sparse packed byte/word integer values from dense memory/register |
VPSHLD | Concatenate and shift packed data left logical |
VPSHLDV | Concatenate and variable shift packed data left logical |
VPSHRD | Concatenate and shift packed data right logical |
VPSHRDV | Concatenate and variable shift packed data right logical |
VNNI
Vector Neural Network Instructions.| Instruction | Description |
VPDPBUSD | Multiply and add unsigned and signed bytes |
VPDPBUSDS | Multiply and add unsigned and signed bytes with saturation |
VPDPWSSD | Multiply and add signed word integers |
VPDPWSSDS | Multiply and add word integers with saturation |
IFMA
VPOPCNTDQ and BITALG
VP2INTERSECT
GFNI
EVEX-encoded Galois field new instructions:| Instruction | Description |
VGF2P8AFFINEINVQB | Galois field affine transformation inverse |
VGF2P8AFFINEQB | Galois field affine transformation |
VGF2P8MULB | Galois field multiply bytes |
VPCLMULQDQ
VPCLMULQDQ with AVX-512F adds EVEX-encoded 512-bit version of PCLMULQDQ instruction. With AVX-512VL, it adds EVEX-encoded 256- and 128-bit versions. VPCLMULQDQ alone adds only VEX-encoded 256-bit version. The wider than 128-bit variations of the instruction perform the same operation on each 128-bit portion of input registers, but they do not extend it to select quadwords from different 128-bit fields.| Instruction | Description |
VPCLMULQDQ | Carry-less multiplication quadword |
VAES
EVEX-encoded AES instructions. The wider than 128-bit variations of the instruction perform the same operation on each 128-bit portion of input registers.| Instruction | Description |
VAESDEC | Perform one round of an AES decryption flow |
VAESDECLAST | Perform last round of an AES decryption flow |
VAESENC | Perform one round of an AES encryption flow |
VAESENCLAST | Perform last round of an AES encryption flow |
BF16
AI acceleration instructions operating on the Bfloat16 format.| Instruction | Description |
VCVTNE2PS2BF16 | Convert two packed single precision numbers to one packed Bfloat16 number |
VCVTNEPS2BF16 | Convert one packed single precision number to one packed Bfloat16 number |
VDPBF16PS | Calculate dot product of two Bfloat16 pairs and accumulate the result into one packed single precision number |
Legacy instructions upgraded with EVEX encoded versions
CPUs with AVX-512
- Intel
- * Knights Landing : AVX-512 F, CD, ER, PF
- * Knights Mill : AVX-512 F, CD, ER, PF, 4FMAPS, 4VNNIW, VPOPCNTDQ
- * Skylake-SP, Skylake-X: AVX-512 F, CD, VL, DQ, BW
- * Cannon Lake: AVX-512 F, CD, VL, DQ, BW, IFMA, VBMI
- * Cascade Lake: AVX-512 F, CD, VL, DQ, BW, VNNI
- * Cooper Lake: AVX-512 F, CD, VL, DQ, BW, VNNI, BF16
- * Ice Lake: AVX-512 F, CD, VL, DQ, BW, IFMA, VBMI, VBMI2, VPOPCNTDQ, BITALG, VNNI, VPCLMULQDQ, GFNI, VAES
- * Tiger Lake: AVX512 F, VL, BW, DQ, CD, VBMI, IFMA, VBMI2, VPOPCNTDQ, BITALG, VNNI, VPCLMULQDQ, GFNI, VAES, VP2INTERSECT
- Centaur Technology
- * "CNS" core
QEMU supports AVX-512.
Performance
supports native AVX-512 performance and vector code quality analysis for 2nd generation Intel Xeon Phi processor. Along with traditional hotspots profile, Advisor Recommendations and "seamless" integration of Intel Compiler vectorization diagnostics, Advisor Survey analysis also provides AVX-512 ISA metrics and new AVX-512-specific "traits", e.g. Scatter, Compress/Expand, mask utilization.AVX-512 causes a frequency throttling even greater than its predecessors, causing a penalty for mixed workloads. The additional downclocking is triggered by the 512-bit width of vectors, and using the 256-bit part of AVX-512 does not trigger it. As a result, gcc defaults to prefer using the 256-bit vectors.