cpu_gccgo_x86.c raw

   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  
   7  #include <cpuid.h>
   8  #include <stdint.h>
   9  #include <x86intrin.h>
  10  
  11  // Need to wrap __get_cpuid_count because it's declared as static.
  12  int
  13  gccgoGetCpuidCount(uint32_t leaf, uint32_t subleaf,
  14                     uint32_t *eax, uint32_t *ebx,
  15                     uint32_t *ecx, uint32_t *edx)
  16  {
  17  	return __get_cpuid_count(leaf, subleaf, eax, ebx, ecx, edx);
  18  }
  19  
  20  #pragma GCC diagnostic ignored "-Wunknown-pragmas"
  21  #pragma GCC push_options
  22  #pragma GCC target("xsave")
  23  #pragma clang attribute push (__attribute__((target("xsave"))), apply_to=function)
  24  
  25  // xgetbv reads the contents of an XCR (Extended Control Register)
  26  // specified in the ECX register into registers EDX:EAX.
  27  // Currently, the only supported value for XCR is 0.
  28  void
  29  gccgoXgetbv(uint32_t *eax, uint32_t *edx)
  30  {
  31  	uint64_t v = _xgetbv(0);
  32  	*eax = v & 0xffffffff;
  33  	*edx = v >> 32;
  34  }
  35  
  36  #pragma clang attribute pop
  37  #pragma GCC pop_options
  38