1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
11 #include "build/build_config.h"
13 #if defined(ARCH_CPU_X86_FAMILY)
36 has_non_stop_time_stamp_counter_(false),
37 cpu_vendor_("unknown") {
41 #if defined(ARCH_CPU_X86_FAMILY)
44 #if defined(__pic__) && defined(__i386__)
46 void __cpuid(int cpu_info
[4], int info_type
) {
51 : "=a"(cpu_info
[0]), "=D"(cpu_info
[1]), "=c"(cpu_info
[2]), "=d"(cpu_info
[3])
56 void __cpuidex(int cpu_info
[4], int info_type
, int info_index
) {
61 : "=a"(cpu_info
[0]), "=D"(cpu_info
[1]), "=c"(cpu_info
[2]), "=d"(cpu_info
[3])
62 : "a"(info_type
), "c"(info_index
)
68 void __cpuid(int cpu_info
[4], int info_type
) {
71 : "=a"(cpu_info
[0]), "=b"(cpu_info
[1]), "=c"(cpu_info
[2]), "=d"(cpu_info
[3])
76 void __cpuidex(int cpu_info
[4], int info_type
, int info_index
) {
79 : "=a"(cpu_info
[0]), "=b"(cpu_info
[1]), "=c"(cpu_info
[2]), "=d"(cpu_info
[3])
80 : "a"(info_type
), "c"(info_index
)
86 #endif // ARCH_CPU_X86_FAMILY
88 void CPU::Initialize() {
89 #if defined(ARCH_CPU_X86_FAMILY)
90 int cpu_info
[4] = {-1};
93 // __cpuid with an InfoType argument of 0 returns the number of
94 // valid Ids in CPUInfo[0] and the CPU identification string in
95 // the other three array elements. The CPU identification string is
96 // not in linear order. The code below arranges the information
97 // in a human readable form. The human readable order is CPUInfo[1] |
98 // CPUInfo[3] | CPUInfo[2]. CPUInfo[2] and CPUInfo[3] are swapped
99 // before using memcpy to copy these three array elements to cpu_string.
100 __cpuid(cpu_info
, 0);
101 int num_ids
= cpu_info
[0];
102 std::swap(cpu_info
[2], cpu_info
[3]);
103 memcpy(cpu_string
, &cpu_info
[1], 3 * sizeof(cpu_info
[1]));
104 cpu_vendor_
.assign(cpu_string
, 3 * sizeof(cpu_info
[1]));
106 // Interpret CPU feature information.
108 __cpuid(cpu_info
, 1);
109 signature_
= cpu_info
[0];
110 stepping_
= cpu_info
[0] & 0xf;
111 model_
= ((cpu_info
[0] >> 4) & 0xf) + ((cpu_info
[0] >> 12) & 0xf0);
112 family_
= (cpu_info
[0] >> 8) & 0xf;
113 type_
= (cpu_info
[0] >> 12) & 0x3;
114 ext_model_
= (cpu_info
[0] >> 16) & 0xf;
115 ext_family_
= (cpu_info
[0] >> 20) & 0xff;
116 has_mmx_
= (cpu_info
[3] & 0x00800000) != 0;
117 has_sse_
= (cpu_info
[3] & 0x02000000) != 0;
118 has_sse2_
= (cpu_info
[3] & 0x04000000) != 0;
119 has_sse3_
= (cpu_info
[2] & 0x00000001) != 0;
120 has_ssse3_
= (cpu_info
[2] & 0x00000200) != 0;
121 has_sse41_
= (cpu_info
[2] & 0x00080000) != 0;
122 has_sse42_
= (cpu_info
[2] & 0x00100000) != 0;
123 has_avx_
= (cpu_info
[2] & 0x10000000) != 0;
126 // Get the brand string of the cpu.
127 __cpuid(cpu_info
, 0x80000000);
128 const int parameter_end
= 0x80000004;
129 int max_parameter
= cpu_info
[0];
131 if (cpu_info
[0] >= parameter_end
) {
132 char* cpu_string_ptr
= cpu_string
;
134 for (int parameter
= 0x80000002; parameter
<= parameter_end
&&
135 cpu_string_ptr
< &cpu_string
[sizeof(cpu_string
)]; parameter
++) {
136 __cpuid(cpu_info
, parameter
);
137 memcpy(cpu_string_ptr
, cpu_info
, sizeof(cpu_info
));
138 cpu_string_ptr
+= sizeof(cpu_info
);
140 cpu_brand_
.assign(cpu_string
, cpu_string_ptr
- cpu_string
);
143 const int parameter_containing_non_stop_time_stamp_counter
= 0x80000007;
144 if (max_parameter
>= parameter_containing_non_stop_time_stamp_counter
) {
145 __cpuid(cpu_info
, parameter_containing_non_stop_time_stamp_counter
);
146 has_non_stop_time_stamp_counter_
= (cpu_info
[3] & (1 << 8)) != 0;
151 CPU::IntelMicroArchitecture
CPU::GetIntelMicroArchitecture() const {
152 if (has_avx()) return AVX
;
153 if (has_sse42()) return SSE42
;
154 if (has_sse41()) return SSE41
;
155 if (has_ssse3()) return SSSE3
;
156 if (has_sse3()) return SSE3
;
157 if (has_sse2()) return SSE2
;
158 if (has_sse()) return SSE
;