1 /*
2 +----------------------------------------------------------------------+
3 | Zend Engine |
4 +----------------------------------------------------------------------+
5 | Copyright (c) Zend Technologies Ltd. (http://www.zend.com) |
6 +----------------------------------------------------------------------+
7 | This source file is subject to version 2.00 of the Zend license, |
8 | that is bundled with this package in the file LICENSE, and is |
9 | available through the world-wide-web at the following url: |
10 | http://www.zend.com/license/2_00.txt. |
11 | If you did not receive a copy of the Zend license and are unable to |
12 | obtain it through the world-wide-web, please send a note to |
13 | license@zend.com so we can mail you a copy immediately. |
14 +----------------------------------------------------------------------+
15 | Authors: Xinchen Hui <xinchen.h@zend.com> |
16 +----------------------------------------------------------------------+
17 */
18
19 #include "zend_cpuinfo.h"
20
21 typedef struct _zend_cpu_info {
22 uint32_t eax;
23 uint32_t ebx;
24 uint32_t ecx;
25 uint32_t edx;
26 uint32_t initialized;
27 } zend_cpu_info;
28
29 static zend_cpu_info cpuinfo = {0};
30
31 #if (defined(__GNUC__) || defined(__clang__)) && (defined(__i386__) || defined(__x86_64__))
32 # if defined(HAVE_CPUID_H) && defined(HAVE_CPUID_COUNT) /* use cpuid.h functions */
33 # include <cpuid.h>
__zend_cpuid(uint32_t func,uint32_t subfunc,zend_cpu_info * cpuinfo)34 static void __zend_cpuid(uint32_t func, uint32_t subfunc, zend_cpu_info *cpuinfo) {
35 __cpuid_count(func, subfunc, cpuinfo->eax, cpuinfo->ebx, cpuinfo->ecx, cpuinfo->edx);
36 }
37 # else /* use inline asm */
__zend_cpuid(uint32_t func,uint32_t subfunc,zend_cpu_info * cpuinfo)38 static void __zend_cpuid(uint32_t func, uint32_t subfunc, zend_cpu_info *cpuinfo) {
39 # if defined(__i386__) && (defined(__pic__) || defined(__PIC__))
40 /* PIC on i386 uses %ebx, so preserve it. */
41 __asm__ __volatile__ (
42 "pushl %%ebx\n"
43 "cpuid\n"
44 "mov %%ebx,%1\n"
45 "popl %%ebx"
46 : "=a"(cpuinfo->eax), "=r"(cpuinfo->ebx), "=c"(cpuinfo->ecx), "=d"(cpuinfo->edx)
47 : "a"(func), "c"(subfunc)
48 );
49 # else
50 __asm__ __volatile__ (
51 "cpuid"
52 : "=a"(cpuinfo->eax), "=b"(cpuinfo->ebx), "=c"(cpuinfo->ecx), "=d"(cpuinfo->edx)
53 : "a"(func), "c"(subfunc)
54 );
55 # endif
56 }
57 # endif
58 #elif defined(_MSC_VER) && !defined(__clang__) && (defined(_M_X64) || defined(_M_IX86)) /* use MSVC __cpuidex intrin */
59 # include <intrin.h>
__zend_cpuid(uint32_t func,uint32_t subfunc,zend_cpu_info * cpuinfo)60 static void __zend_cpuid(uint32_t func, uint32_t subfunc, zend_cpu_info *cpuinfo) {
61 int regs[4];
62
63 __cpuidex(regs, func, subfunc);
64
65 cpuinfo->eax = regs[0];
66 cpuinfo->ebx = regs[1];
67 cpuinfo->ecx = regs[2];
68 cpuinfo->edx = regs[3];
69 }
70 #else /* fall back to zero */
__zend_cpuid(uint32_t func,uint32_t subfunc,zend_cpu_info * cpuinfo)71 static void __zend_cpuid(uint32_t func, uint32_t subfunc, zend_cpu_info *cpuinfo) {
72 cpuinfo->eax = 0;
73 }
74 #endif
75
76 #if defined(__i386__) || defined(__x86_64__) || defined(_M_X64) || defined(_M_IX86)
77 /* Function based on compiler-rt implementation. */
get_xcr0_eax(void)78 static unsigned get_xcr0_eax(void) {
79 # if defined(__GNUC__) || defined(__clang__)
80 // Check xgetbv; this uses a .byte sequence instead of the instruction
81 // directly because older assemblers do not include support for xgetbv and
82 // there is no easy way to conditionally compile based on the assembler used.
83 unsigned eax, edx;
84 __asm__(".byte 0x0f, 0x01, 0xd0" : "=a"(eax), "=d"(edx) : "c"(0));
85 return eax;
86 # elif defined(ZEND_WIN32) && defined(_XCR_XFEATURE_ENABLED_MASK)
87 return _xgetbv(_XCR_XFEATURE_ENABLED_MASK);
88 # else
89 return 0;
90 # endif
91 }
92
is_avx_supported(void)93 static bool is_avx_supported(void) {
94 if (!(cpuinfo.ecx & ZEND_CPU_FEATURE_AVX)) {
95 /* No support for AVX */
96 return 0;
97 }
98 if (!(cpuinfo.ecx & ZEND_CPU_FEATURE_OSXSAVE)) {
99 /* The operating system does not support XSAVE. */
100 return 0;
101 }
102 if ((get_xcr0_eax() & 0x6) != 0x6) {
103 /* XCR0 SSE and AVX bits must be set. */
104 return 0;
105 }
106 return 1;
107 }
108 #else
is_avx_supported(void)109 static bool is_avx_supported(void) {
110 return 0;
111 }
112 #endif
113
zend_cpu_startup(void)114 void zend_cpu_startup(void)
115 {
116 if (!cpuinfo.initialized) {
117 zend_cpu_info ebx;
118 int max_feature;
119
120 cpuinfo.initialized = 1;
121 __zend_cpuid(0, 0, &cpuinfo);
122 max_feature = cpuinfo.eax;
123 if (max_feature == 0) {
124 return;
125 }
126
127 __zend_cpuid(1, 0, &cpuinfo);
128
129 /* for avx2 */
130 if (max_feature >= 7) {
131 __zend_cpuid(7, 0, &ebx);
132 cpuinfo.ebx = ebx.ebx;
133 } else {
134 cpuinfo.ebx = 0;
135 }
136
137 if (!is_avx_supported()) {
138 cpuinfo.edx &= ~ZEND_CPU_FEATURE_AVX;
139 cpuinfo.ebx &= ~(ZEND_CPU_FEATURE_AVX2 & ~ZEND_CPU_EBX_MASK);
140 }
141 }
142 }
143
zend_cpu_supports(zend_cpu_feature feature)144 ZEND_API int zend_cpu_supports(zend_cpu_feature feature) {
145 ZEND_ASSERT(cpuinfo.initialized);
146 if (feature & ZEND_CPU_EDX_MASK) {
147 return (cpuinfo.edx & (feature & ~ZEND_CPU_EDX_MASK));
148 } else if (feature & ZEND_CPU_EBX_MASK) {
149 return (cpuinfo.ebx & (feature & ~ZEND_CPU_EBX_MASK));
150 } else {
151 return (cpuinfo.ecx & feature);
152 }
153 }
154
