github.com/gogf/gkafka@v1.0.1-0.20190702070843-033a14468069/third/golang.org/x/sys/cpu/cpu_gccgo.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  // +build 386 amd64 amd64p32
     6  // +build gccgo
     7  
     8  #include <cpuid.h>
     9  #include <stdint.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  // xgetbv reads the contents of an XCR (Extended Control Register)
    21  // specified in the ECX register into registers EDX:EAX.
    22  // Currently, the only supported value for XCR is 0.
    23  //
    24  // TODO: Replace with a better alternative:
    25  //
    26  //     #include <xsaveintrin.h>
    27  //
    28  //     #pragma GCC target("xsave")
    29  //
    30  //     void gccgoXgetbv(uint32_t *eax, uint32_t *edx) {
    31  //       unsigned long long x = _xgetbv(0);
    32  //       *eax = x & 0xffffffff;
    33  //       *edx = (x >> 32) & 0xffffffff;
    34  //     }
    35  //
    36  // Note that _xgetbv is defined starting with GCC 8.
    37  void
    38  gccgoXgetbv(uint32_t *eax, uint32_t *edx)
    39  {
    40  	__asm("  xorl %%ecx, %%ecx\n"
    41  	      "  xgetbv"
    42  	    : "=a"(*eax), "=d"(*edx));
    43  }