44 lines
1.2 KiB
C
44 lines
1.2 KiB
C
// Copyright 2018 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// +build 386 amd64 amd64p32
|
|
// +build gccgo
|
|
|
|
#include <cpuid.h>
|
|
#include <stdint.h>
|
|
|
|
// Need to wrap __get_cpuid_count because it's declared as static.
|
|
int
|
|
gccgoGetCpuidCount(uint32_t leaf, uint32_t subleaf,
|
|
uint32_t *eax, uint32_t *ebx,
|
|
uint32_t *ecx, uint32_t *edx)
|
|
{
|
|
return __get_cpuid_count(leaf, subleaf, eax, ebx, ecx, edx);
|
|
}
|
|
|
|
// xgetbv reads the contents of an XCR (Extended Control Register)
|
|
// specified in the ECX register into registers EDX:EAX.
|
|
// Currently, the only supported value for XCR is 0.
|
|
//
|
|
// TODO: Replace with a better alternative:
|
|
//
|
|
// #include <xsaveintrin.h>
|
|
//
|
|
// #pragma GCC target("xsave")
|
|
//
|
|
// void gccgoXgetbv(uint32_t *eax, uint32_t *edx) {
|
|
// unsigned long long x = _xgetbv(0);
|
|
// *eax = x & 0xffffffff;
|
|
// *edx = (x >> 32) & 0xffffffff;
|
|
// }
|
|
//
|
|
// Note that _xgetbv is defined starting with GCC 8.
|
|
void
|
|
gccgoXgetbv(uint32_t *eax, uint32_t *edx)
|
|
{
|
|
__asm(" xorl %%ecx, %%ecx\n"
|
|
" xgetbv"
|
|
: "=a"(*eax), "=d"(*edx));
|
|
}
|