1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
|
#define _UMATHMODULE
#define _MULTIARRAYMODULE
#define NPY_NO_DEPRECATED_API NPY_API_VERSION
#include <Python.h>
#include "npy_config.h"
#include "cpuid.h"
#define XCR_XFEATURE_ENABLED_MASK 0x0
#define XSTATE_SSE 0x2
#define XSTATE_YMM 0x4
#define XSTATE_ZMM 0x70
/*
* verify the OS supports avx instructions
* it can be disabled in some OS, e.g. with the nosavex boot option of linux
*/
static NPY_INLINE
int os_avx_support(void)
{
#if HAVE_XGETBV
/*
* use bytes for xgetbv to avoid issues with compiler not knowing the
* instruction
*/
unsigned int eax, edx;
unsigned int ecx = XCR_XFEATURE_ENABLED_MASK;
__asm__("xgetbv" : "=a" (eax), "=d" (edx) : "c" (ecx));
return (eax & (XSTATE_SSE | XSTATE_YMM)) == (XSTATE_SSE | XSTATE_YMM);
#else
return 0;
#endif
}
static NPY_INLINE
int os_avx512_support(void)
{
#if HAVE_XGETBV
unsigned int eax, edx;
unsigned int ecx = XCR_XFEATURE_ENABLED_MASK;
unsigned int xcr0 = XSTATE_ZMM | XSTATE_YMM | XSTATE_SSE;
__asm__("xgetbv" : "=a" (eax), "=d" (edx) : "c" (ecx));
return (eax & xcr0) == xcr0;
#else
return 0;
#endif
}
static NPY_INLINE
int cpu_supports_fma(void)
{
#ifdef __x86_64__
unsigned int feature = 0x01;
unsigned int a, b, c, d;
__asm__ volatile (
"cpuid" "\n\t"
: "=a" (a), "=b" (b), "=c" (c), "=d" (d)
: "a" (feature));
/*
* FMA is the 12th bit of ECX
*/
return (c >> 12) & 1;
#else
return 0;
#endif
}
/*
* Primitive cpu feature detect function
* Currently only supports checking for avx on gcc compatible compilers.
*/
NPY_NO_EXPORT int
npy_cpu_supports(const char * feature)
{
#ifdef HAVE___BUILTIN_CPU_SUPPORTS
if (strcmp(feature, "avx512f") == 0) {
#ifdef HAVE___BUILTIN_CPU_SUPPORTS_AVX512F
return __builtin_cpu_supports("avx512f") && os_avx512_support();
#else
return 0;
#endif
}
else if (strcmp(feature, "fma") == 0) {
return cpu_supports_fma() && __builtin_cpu_supports("avx2") && os_avx_support();
}
else if (strcmp(feature, "avx2") == 0) {
return __builtin_cpu_supports("avx2") && os_avx_support();
}
else if (strcmp(feature, "avx") == 0) {
return __builtin_cpu_supports("avx") && os_avx_support();
}
#endif
return 0;
}
|
