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| | ;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2021 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (guix cpu)
#:use-module (guix sets)
#:use-module (guix memoization)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-9)
#:use-module (ice-9 match)
#:use-module (ice-9 rdelim)
#:export (current-cpu
cpu?
cpu-architecture
cpu-family
cpu-model
cpu-flags
cpu->gcc-architecture))
;;; Commentary:
;;;
;;; This module provides tools to determine the micro-architecture supported
;;; by the CPU and to map it to a name known to GCC's '-march'.
;;;
;;; Code:
;; CPU description.
(define-record-type <cpu>
(cpu architecture family model flags)
cpu?
(architecture cpu-architecture) ;string, from 'uname'
(family cpu-family) ;integer
(model cpu-model) ;integer
(flags cpu-flags)) ;set of strings
(define current-cpu
(mlambda ()
"Return a <cpu> record representing the host CPU."
(define (prefix? prefix)
(lambda (str)
(string-prefix? prefix str)))
(call-with-input-file "/proc/cpuinfo"
(lambda (port)
(let loop ((family #f)
(model #f))
(match (read-line port)
((? eof-object?)
#f)
((? (prefix? "cpu family") str)
(match (string-tokenize str)
(("cpu" "family" ":" family)
(loop (string->number family) model))))
((? (prefix? "model") str)
(match (string-tokenize str)
(("model" ":" model)
(loop family (string->number model)))
(_
(loop family model))))
((? (prefix? "flags") str)
(match (string-tokenize str)
(("flags" ":" flags ...)
(cpu (utsname:machine (uname))
family model (list->set flags)))))
(_
(loop family model))))))))
(define (cpu->gcc-architecture cpu)
"Return the architecture name, suitable for GCC's '-march' flag, that
corresponds to CPU, a record as returned by 'current-cpu'."
(match (cpu-architecture cpu)
("x86_64"
;; Transcribed from GCC's 'host_detect_local_cpu' in driver-i386.c.
(or (and (= 6 (cpu-family cpu)) ;the "Pentium Pro" family
(letrec-syntax ((model (syntax-rules (=>)
((_) #f)
((_ (candidate => integers ...) rest
...)
(or (and (= (cpu-model cpu) integers)
candidate)
...
(model rest ...))))))
(model ("bonnel" => #x1c #x26)
("silvermont" => #x37 #x4a #x4d #x5a #x5d)
("core2" => #x0f #x17 #x1d)
("nehalem" => #x1a #x1e #x1f #x2e)
("westmere" => #x25 #x2c #x2f)
("sandybridge" => #x2a #x2d)
("ivybridge" => #x3a #x3e)
("haswell" => #x3c #x3f #x45 #x46)
("broadwell" => #x3d #x47 #x4f #x56)
("skylake" => #x4e #x5e #x8e #x9e)
("skylake-avx512" => #x55) ;TODO: cascadelake
("knl" => #x57)
("cannonlake" => #x66)
("knm" => #x85))))
;; Fallback case for non-Intel processors or for Intel processors not
;; recognized above.
(letrec-syntax ((if-flags (syntax-rules (=>)
((_)
#f)
((_ (flags ... => name) rest ...)
(if (every (lambda (flag)
(set-contains? (cpu-flags cpu)
flag))
'(flags ...))
name
(if-flags rest ...))))))
(if-flags ("avx512" => "knl")
("adx" => "broadwell")
("avx2" => "haswell")
;; TODO: tigerlake, cooperlake, etc.
("avx" => "sandybridge")
("sse4_2" "movbe" => "silvermont")
("sse4_2" => "nehalem")
("ssse3" "movbe" => "bonnell")
("ssse3" => "core2")))
"x86_64"))
(architecture
;; TODO: AArch64.
architecture)))
|