github.com/neonyo/sys@v0.0.0-20230720094341-b1ee14be3ce8/cpu/cpu_gccgo_x86.c (about)

     1  // Copyright 2018 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build (386 || amd64 || amd64p32) && gccgo
     6  // +build 386 amd64 amd64p32
     7  // +build gccgo
     8  
     9  #include <cpuid.h>
    10  #include <stdint.h>
    11  #include <x86intrin.h>
    12  
    13  // Need to wrap __get_cpuid_count because it's declared as static.
    14  int
    15  gccgoGetCpuidCount(uint32_t leaf, uint32_t subleaf,
    16                     uint32_t *eax, uint32_t *ebx,
    17                     uint32_t *ecx, uint32_t *edx)
    18  {
    19  	return __get_cpuid_count(leaf, subleaf, eax, ebx, ecx, edx);
    20  }
    21  
    22  #pragma GCC diagnostic ignored "-Wunknown-pragmas"
    23  #pragma GCC push_options
    24  #pragma GCC target("xsave")
    25  #pragma clang attribute push (__attribute__((target("xsave"))), apply_to=function)
    26  
    27  // xgetbv reads the contents of an XCR (Extended Control Register)
    28  // specified in the ECX register into registers EDX:EAX.
    29  // Currently, the only supported value for XCR is 0.
    30  void
    31  gccgoXgetbv(uint32_t *eax, uint32_t *edx)
    32  {
    33  	uint64_t v = _xgetbv(0);
    34  	*eax = v & 0xffffffff;
    35  	*edx = v >> 32;
    36  }
    37  
    38  #pragma clang attribute pop
    39  #pragma GCC pop_options