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# core.cpuid

Identify the characteristics of the host CPU, providing information about cache sizes and assembly optimisation hints. This module is provided primarily for assembly language programmers.

References Some of this information was extremely difficult to track down. Some of the documents below were found only in cached versions stored by search engines! This code relies on information found in:

- "Intel(R) 64 and IA-32 Architectures Software Developers Manual, Volume 2A: Instruction Set Reference, A-M" (2007).
- "AMD CPUID Specification", Advanced Micro Devices, Rev 2.28 (2008).
- "AMD Processor Recognition Application Note For Processors Prior to AMD Family 0Fh Processors", Advanced Micro Devices, Rev 3.13 (2005).
- "AMD Geode(TM) GX Processors Data Book", Advanced Micro Devices, Publication ID 31505E, (2005).
- "AMD K6 Processor Code Optimisation", Advanced Micro Devices, Rev D (2000).
- "Application note 106: Software Customization for the 6x86 Family", Cyrix Corporation, Rev 1.5 (1998)
- http://www.datasheetcatalog.org/datasheet/nationalsemiconductor/GX1.pdf
- "Geode(TM) GX1 Processor Series Low Power Integrated X86 Solution", National Semiconductor, (2002)
- "The VIA Isaiah Architecture", G. Glenn Henry, Centaur Technology, Inc (2008).
- http://www.sandpile.org/ia32/cpuid.htm
- http://www.akkadia.org/drepper/cpumemory.pdf
- "What every programmer should know about memory", Ulrich Depper, Red Hat, Inc., (2007).
- "CPU Identification by the Windows Kernel", G. Chappell (2009). http://www.geoffchappell.com/viewer.htm?doc=studies/windows/km/cpu/cx8.htm
- "Intel(R) Processor Identification and the CPUID Instruction, Application Note 485" (2009).

Bugs:
Currently only works on x86 and Itanium CPUs. Many processors have bugs in their microcode for the CPUID instruction, so sometimes the cache information may be incorrect.
License:
Boost License 1.0
Authors:
Don Clugston, Tomas Lindquist Olsen <tomas@famolsen.dk>

Source core/cpuid.d

struct `CacheInfo`;
  Cache size and behaviour
  size_t `size`;
    Size of the cache, in kilobytes, per CPU. For L1 unified (data + code) caches, this `size` is half the physical `size`. (we don't halve it for larger sizes, since normally data `size` is much greater than code `size` for critical loops).
  ubyte `associativity`;
    Number of ways of `associativity`, eg:
    - 1 = direct mapped
    - 2 = 2-way set associative
    - 3 = 3-way set associative
    - ubyte.max = fully associative
  uint `lineSize`;
    Number of bytes read into the cache when a cache miss occurs.
CacheInfo[5] `datacache`;
  Scheduled for deprecation. Please use dataCaches instead.
pure nothrow @nogc @property @trusted const(CacheInfo)[5] `dataCaches`();
  The data caches. If there are fewer than 5 physical caches levels, the remaining levels are set to size_t.max (== entire memory space)
pure nothrow @nogc @property @trusted string `vendor`();
  Returns `vendor` string, for display purposes only. Do NOT use this to determine features! Note that some CPUs have programmable vendorIDs.
pure nothrow @nogc @property @trusted string `processor`();
  Returns `processor` string, for display purposes only
pure nothrow @nogc @property @trusted bool `x87onChip`();
  Does it have an x87 FPU on-chip?
pure nothrow @nogc @property @trusted bool `mmx`();
  Is MMX supported?
pure nothrow @nogc @property @trusted bool `sse`();
  Is SSE supported?
pure nothrow @nogc @property @trusted bool `sse2`();
  Is SSE2 supported?
pure nothrow @nogc @property @trusted bool `sse3`();
  Is SSE3 supported?
pure nothrow @nogc @property @trusted bool `ssse3`();
  Is SSSE3 supported?
pure nothrow @nogc @property @trusted bool `sse41`();
  Is SSE4.1 supported?
pure nothrow @nogc @property @trusted bool `sse42`();
  Is SSE4.2 supported?
pure nothrow @nogc @property @trusted bool `sse4a`();
  Is SSE4a supported?
pure nothrow @nogc @property @trusted bool `aes`();
  Is AES supported
pure nothrow @nogc @property @trusted bool `hasPclmulqdq`();
  Is pclmulqdq supported
pure nothrow @nogc @property @trusted bool `hasRdrand`();
  Is rdrand supported
pure nothrow @nogc @property @trusted bool `avx`();
  Is AVX supported
pure nothrow @nogc @property @trusted bool `vaes`();
  Is VEX-Encoded AES supported
pure nothrow @nogc @property @trusted bool `hasVpclmulqdq`();
  Is vpclmulqdq supported
pure nothrow @nogc @property @trusted bool `fma`();
  Is FMA supported
pure nothrow @nogc @property @trusted bool `fp16c`();
  Is FP16C supported
pure nothrow @nogc @property @trusted bool `avx2`();
  Is AVX2 supported
pure nothrow @nogc @property @trusted bool `hle`();
  Is HLE (hardware lock elision) supported
pure nothrow @nogc @property @trusted bool `rtm`();
  Is RTM (restricted transactional memory) supported
pure nothrow @nogc @property @trusted bool `hasRdseed`();
  Is rdseed supported
pure nothrow @nogc @property @trusted bool `hasSha`();
  Is SHA supported
pure nothrow @nogc @property @trusted bool `amd3dnow`();
  Is AMD 3DNOW supported?
pure nothrow @nogc @property @trusted bool `amd3dnowExt`();
  Is AMD 3DNOW Ext supported?
pure nothrow @nogc @property @trusted bool `amdMmx`();
  Are AMD extensions to MMX supported?
pure nothrow @nogc @property @trusted bool `hasFxsr`();
  Is fxsave/fxrstor supported?
pure nothrow @nogc @property @trusted bool `hasCmov`();
  Is cmov supported?
pure nothrow @nogc @property @trusted bool `hasRdtsc`();
  Is rdtsc supported?
pure nothrow @nogc @property @trusted bool `hasCmpxchg8b`();
  Is cmpxchg8b supported?
pure nothrow @nogc @property @trusted bool `hasCmpxchg16b`();
  Is cmpxchg8b supported?
pure nothrow @nogc @property @trusted bool `hasSysEnterSysExit`();
  Is SYSENTER/SYSEXIT supported?
pure nothrow @nogc @property @trusted bool `has3dnowPrefetch`();
  Is 3DNow prefetch supported?
pure nothrow @nogc @property @trusted bool `hasLahfSahf`();
  Are LAHF and SAHF supported in 64-bit mode?
pure nothrow @nogc @property @trusted bool `hasPopcnt`();
  Is POPCNT supported?
pure nothrow @nogc @property @trusted bool `hasLzcnt`();
  Is LZCNT supported?
pure nothrow @nogc @property @trusted bool `isX86_64`();
  Is this an Intel64 or AMD 64?
pure nothrow @nogc @property @trusted bool `isItanium`();
  Is this an IA64 (Itanium) processor?
pure nothrow @nogc @property @trusted bool `hyperThreading`();
  Is hyperthreading supported?
pure nothrow @nogc @property @trusted uint `threadsPerCPU`();
  Returns number of threads per CPU
pure nothrow @nogc @property @trusted uint `coresPerCPU`();
  Returns number of cores in CPU
pure nothrow @nogc @property @trusted bool `preferAthlon`();
  Optimisation hints for assembly code.
  For forward compatibility, the CPU is compared against different microarchitectures. For 32-bit x86, comparisons are made against the Intel PPro/PII/PIII/PM family.
  The major 32-bit x86 microarchitecture 'dynasties' have been:
  - Intel P6 (PentiumPro, PII, PIII, PM, Core, Core2).
  - AMD Athlon (K7, K8, K10).
  - Intel NetBurst (Pentium 4, Pentium D).
  - In-order Pentium (Pentium1, PMMX, Atom)
  Other early CPUs (Nx586, AMD K5, K6, Centaur C3, Transmeta, Cyrix, Rise) were mostly in-order.
  Some new processors do not fit into the existing categories:
  - Intel Atom 230/330 (family 6, model 0x1C) is an in-order core.
  - Centaur Isiah = VIA Nano (family 6, model F) is an out-of-order core.
  Within each dynasty, the optimisation techniques are largely identical (eg, use instruction pairing for group 4). Major instruction set improvements occur within each dynasty.
  Does this CPU perform better on AMD K7 code than PentiumPro..Core2 code?
pure nothrow @nogc @property @trusted bool `preferPentium4`();
  Does this CPU perform better on Pentium4 code than PentiumPro..Core2 code?
pure nothrow @nogc @property @trusted bool `preferPentium1`();
  Does this CPU perform better on Pentium I code than Pentium Pro code?
uint `stepping`;
  Warning: This field will be turned into a property in a future release.
  Processor type (vendor-dependent). This should be visible ONLY for display purposes.
uint `model`;
  Warning: This field will be turned into a property in a future release.
  Processor type (vendor-dependent). This should be visible ONLY for display purposes.
uint `family`;
  Warning: This field will be turned into a property in a future release.
  Processor type (vendor-dependent). This should be visible ONLY for display purposes.
uint `numCacheLevels`;
  This field has been deprecated. Please use cacheLevels instead.
nothrow @nogc @property @trusted uint `cacheLevels`();
  The number of cache levels in the CPU.

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