1// Copyright 2013 the V8 project 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.
4
5#include "src/base/cpu.h"
6
7#if V8_LIBC_MSVCRT
8#include <intrin.h>  // __cpuid()
9#endif
10#if V8_OS_LINUX
11#include <linux/auxvec.h>  // AT_HWCAP
12#endif
13#if V8_GLIBC_PREREQ(2, 16)
14#include <sys/auxv.h>  // getauxval()
15#endif
16#if V8_OS_QNX
17#include <sys/syspage.h>  // cpuinfo
18#endif
19#if V8_OS_LINUX && V8_HOST_ARCH_PPC
20#include <elf.h>
21#endif
22#if V8_OS_AIX
23#include <sys/systemcfg.h>  // _system_configuration
24#ifndef POWER_8
25#define POWER_8 0x10000
26#endif
27#endif
28#if V8_OS_POSIX
29#include <unistd.h>  // sysconf()
30#endif
31
32#include <ctype.h>
33#include <limits.h>
34#include <stdio.h>
35#include <stdlib.h>
36#include <string.h>
37#include <algorithm>
38
39#include "src/base/logging.h"
40#if V8_OS_WIN
41#include "src/base/win32-headers.h"  // NOLINT
42#endif
43
44namespace v8 {
45namespace base {
46
47#if defined(__pnacl__)
48// Portable host shouldn't do feature detection.
49#elif V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64
50
51// Define __cpuid() for non-MSVC libraries.
52#if !V8_LIBC_MSVCRT
53
54static V8_INLINE void __cpuid(int cpu_info[4], int info_type) {
55// Clear ecx to align with __cpuid() of MSVC:
56// https://msdn.microsoft.com/en-us/library/hskdteyh.aspx
57#if defined(__i386__) && defined(__pic__)
58  // Make sure to preserve ebx, which contains the pointer
59  // to the GOT in case we're generating PIC.
60  __asm__ volatile(
61      "mov %%ebx, %%edi\n\t"
62      "cpuid\n\t"
63      "xchg %%edi, %%ebx\n\t"
64      : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]),
65        "=d"(cpu_info[3])
66      : "a"(info_type), "c"(0));
67#else
68  __asm__ volatile("cpuid \n\t"
69                   : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]),
70                     "=d"(cpu_info[3])
71                   : "a"(info_type), "c"(0));
72#endif  // defined(__i386__) && defined(__pic__)
73}
74
75#endif  // !V8_LIBC_MSVCRT
76
77#elif V8_HOST_ARCH_ARM || V8_HOST_ARCH_ARM64 \
78    || V8_HOST_ARCH_MIPS || V8_HOST_ARCH_MIPS64
79
80#if V8_OS_LINUX
81
82#if V8_HOST_ARCH_ARM
83
84// See <uapi/asm/hwcap.h> kernel header.
85/*
86 * HWCAP flags - for elf_hwcap (in kernel) and AT_HWCAP
87 */
88#define HWCAP_SWP (1 << 0)
89#define HWCAP_HALF  (1 << 1)
90#define HWCAP_THUMB (1 << 2)
91#define HWCAP_26BIT (1 << 3)  /* Play it safe */
92#define HWCAP_FAST_MULT (1 << 4)
93#define HWCAP_FPA (1 << 5)
94#define HWCAP_VFP (1 << 6)
95#define HWCAP_EDSP  (1 << 7)
96#define HWCAP_JAVA  (1 << 8)
97#define HWCAP_IWMMXT  (1 << 9)
98#define HWCAP_CRUNCH  (1 << 10)
99#define HWCAP_THUMBEE (1 << 11)
100#define HWCAP_NEON  (1 << 12)
101#define HWCAP_VFPv3 (1 << 13)
102#define HWCAP_VFPv3D16  (1 << 14) /* also set for VFPv4-D16 */
103#define HWCAP_TLS (1 << 15)
104#define HWCAP_VFPv4 (1 << 16)
105#define HWCAP_IDIVA (1 << 17)
106#define HWCAP_IDIVT (1 << 18)
107#define HWCAP_VFPD32  (1 << 19) /* set if VFP has 32 regs (not 16) */
108#define HWCAP_IDIV  (HWCAP_IDIVA | HWCAP_IDIVT)
109#define HWCAP_LPAE  (1 << 20)
110
111static uint32_t ReadELFHWCaps() {
112  uint32_t result = 0;
113#if V8_GLIBC_PREREQ(2, 16)
114  result = static_cast<uint32_t>(getauxval(AT_HWCAP));
115#else
116  // Read the ELF HWCAP flags by parsing /proc/self/auxv.
117  FILE* fp = fopen("/proc/self/auxv", "r");
118  if (fp != NULL) {
119    struct { uint32_t tag; uint32_t value; } entry;
120    for (;;) {
121      size_t n = fread(&entry, sizeof(entry), 1, fp);
122      if (n == 0 || (entry.tag == 0 && entry.value == 0)) {
123        break;
124      }
125      if (entry.tag == AT_HWCAP) {
126        result = entry.value;
127        break;
128      }
129    }
130    fclose(fp);
131  }
132#endif
133  return result;
134}
135
136#endif  // V8_HOST_ARCH_ARM
137
138#if V8_HOST_ARCH_MIPS
139int __detect_fp64_mode(void) {
140  double result = 0;
141  // Bit representation of (double)1 is 0x3FF0000000000000.
142  __asm__ volatile(
143      ".set push\n\t"
144      ".set noreorder\n\t"
145      ".set oddspreg\n\t"
146      "lui $t0, 0x3FF0\n\t"
147      "ldc1 $f0, %0\n\t"
148      "mtc1 $t0, $f1\n\t"
149      "sdc1 $f0, %0\n\t"
150      ".set pop\n\t"
151      : "+m"(result)
152      :
153      : "t0", "$f0", "$f1", "memory");
154
155  return !(result == 1);
156}
157
158
159int __detect_mips_arch_revision(void) {
160  // TODO(dusmil): Do the specific syscall as soon as it is implemented in mips
161  // kernel.
162  uint32_t result = 0;
163  __asm__ volatile(
164      "move $v0, $zero\n\t"
165      // Encoding for "addi $v0, $v0, 1" on non-r6,
166      // which is encoding for "bovc $v0, %v0, 1" on r6.
167      // Use machine code directly to avoid compilation errors with different
168      // toolchains and maintain compatibility.
169      ".word 0x20420001\n\t"
170      "sw $v0, %0\n\t"
171      : "=m"(result)
172      :
173      : "v0", "memory");
174  // Result is 0 on r6 architectures, 1 on other architecture revisions.
175  // Fall-back to the least common denominator which is mips32 revision 1.
176  return result ? 1 : 6;
177}
178#endif
179
180// Extract the information exposed by the kernel via /proc/cpuinfo.
181class CPUInfo final {
182 public:
183  CPUInfo() : datalen_(0) {
184    // Get the size of the cpuinfo file by reading it until the end. This is
185    // required because files under /proc do not always return a valid size
186    // when using fseek(0, SEEK_END) + ftell(). Nor can the be mmap()-ed.
187    static const char PATHNAME[] = "/proc/cpuinfo";
188    FILE* fp = fopen(PATHNAME, "r");
189    if (fp != NULL) {
190      for (;;) {
191        char buffer[256];
192        size_t n = fread(buffer, 1, sizeof(buffer), fp);
193        if (n == 0) {
194          break;
195        }
196        datalen_ += n;
197      }
198      fclose(fp);
199    }
200
201    // Read the contents of the cpuinfo file.
202    data_ = new char[datalen_ + 1];
203    fp = fopen(PATHNAME, "r");
204    if (fp != NULL) {
205      for (size_t offset = 0; offset < datalen_; ) {
206        size_t n = fread(data_ + offset, 1, datalen_ - offset, fp);
207        if (n == 0) {
208          break;
209        }
210        offset += n;
211      }
212      fclose(fp);
213    }
214
215    // Zero-terminate the data.
216    data_[datalen_] = '\0';
217  }
218
219  ~CPUInfo() {
220    delete[] data_;
221  }
222
223  // Extract the content of a the first occurence of a given field in
224  // the content of the cpuinfo file and return it as a heap-allocated
225  // string that must be freed by the caller using delete[].
226  // Return NULL if not found.
227  char* ExtractField(const char* field) const {
228    DCHECK(field != NULL);
229
230    // Look for first field occurence, and ensure it starts the line.
231    size_t fieldlen = strlen(field);
232    char* p = data_;
233    for (;;) {
234      p = strstr(p, field);
235      if (p == NULL) {
236        return NULL;
237      }
238      if (p == data_ || p[-1] == '\n') {
239        break;
240      }
241      p += fieldlen;
242    }
243
244    // Skip to the first colon followed by a space.
245    p = strchr(p + fieldlen, ':');
246    if (p == NULL || !isspace(p[1])) {
247      return NULL;
248    }
249    p += 2;
250
251    // Find the end of the line.
252    char* q = strchr(p, '\n');
253    if (q == NULL) {
254      q = data_ + datalen_;
255    }
256
257    // Copy the line into a heap-allocated buffer.
258    size_t len = q - p;
259    char* result = new char[len + 1];
260    if (result != NULL) {
261      memcpy(result, p, len);
262      result[len] = '\0';
263    }
264    return result;
265  }
266
267 private:
268  char* data_;
269  size_t datalen_;
270};
271
272#if V8_HOST_ARCH_ARM || V8_HOST_ARCH_MIPS || V8_HOST_ARCH_MIPS64
273
274// Checks that a space-separated list of items contains one given 'item'.
275static bool HasListItem(const char* list, const char* item) {
276  ssize_t item_len = strlen(item);
277  const char* p = list;
278  if (p != NULL) {
279    while (*p != '\0') {
280      // Skip whitespace.
281      while (isspace(*p)) ++p;
282
283      // Find end of current list item.
284      const char* q = p;
285      while (*q != '\0' && !isspace(*q)) ++q;
286
287      if (item_len == q - p && memcmp(p, item, item_len) == 0) {
288        return true;
289      }
290
291      // Skip to next item.
292      p = q;
293    }
294  }
295  return false;
296}
297
298#endif  // V8_HOST_ARCH_ARM || V8_HOST_ARCH_MIPS || V8_HOST_ARCH_MIPS64
299
300#endif  // V8_OS_LINUX
301
302#endif  // V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64
303
304CPU::CPU()
305    : stepping_(0),
306      model_(0),
307      ext_model_(0),
308      family_(0),
309      ext_family_(0),
310      type_(0),
311      implementer_(0),
312      architecture_(0),
313      variant_(-1),
314      part_(0),
315      has_fpu_(false),
316      has_cmov_(false),
317      has_sahf_(false),
318      has_mmx_(false),
319      has_sse_(false),
320      has_sse2_(false),
321      has_sse3_(false),
322      has_ssse3_(false),
323      has_sse41_(false),
324      has_sse42_(false),
325      is_atom_(false),
326      has_osxsave_(false),
327      has_avx_(false),
328      has_fma3_(false),
329      has_bmi1_(false),
330      has_bmi2_(false),
331      has_lzcnt_(false),
332      has_popcnt_(false),
333      has_idiva_(false),
334      has_neon_(false),
335      has_thumb2_(false),
336      has_vfp_(false),
337      has_vfp3_(false),
338      has_vfp3_d32_(false),
339      is_fp64_mode_(false) {
340  memcpy(vendor_, "Unknown", 8);
341#if V8_OS_NACL
342// Portable host shouldn't do feature detection.
343// TODO(jfb): Remove the hardcoded ARM simulator flags in the build, and
344// hardcode them here instead.
345#elif V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64
346  int cpu_info[4];
347
348  // __cpuid with an InfoType argument of 0 returns the number of
349  // valid Ids in CPUInfo[0] and the CPU identification string in
350  // the other three array elements. The CPU identification string is
351  // not in linear order. The code below arranges the information
352  // in a human readable form. The human readable order is CPUInfo[1] |
353  // CPUInfo[3] | CPUInfo[2]. CPUInfo[2] and CPUInfo[3] are swapped
354  // before using memcpy to copy these three array elements to cpu_string.
355  __cpuid(cpu_info, 0);
356  unsigned num_ids = cpu_info[0];
357  std::swap(cpu_info[2], cpu_info[3]);
358  memcpy(vendor_, cpu_info + 1, 12);
359  vendor_[12] = '\0';
360
361  // Interpret CPU feature information.
362  if (num_ids > 0) {
363    __cpuid(cpu_info, 1);
364    stepping_ = cpu_info[0] & 0xf;
365    model_ = ((cpu_info[0] >> 4) & 0xf) + ((cpu_info[0] >> 12) & 0xf0);
366    family_ = (cpu_info[0] >> 8) & 0xf;
367    type_ = (cpu_info[0] >> 12) & 0x3;
368    ext_model_ = (cpu_info[0] >> 16) & 0xf;
369    ext_family_ = (cpu_info[0] >> 20) & 0xff;
370    has_fpu_ = (cpu_info[3] & 0x00000001) != 0;
371    has_cmov_ = (cpu_info[3] & 0x00008000) != 0;
372    has_mmx_ = (cpu_info[3] & 0x00800000) != 0;
373    has_sse_ = (cpu_info[3] & 0x02000000) != 0;
374    has_sse2_ = (cpu_info[3] & 0x04000000) != 0;
375    has_sse3_ = (cpu_info[2] & 0x00000001) != 0;
376    has_ssse3_ = (cpu_info[2] & 0x00000200) != 0;
377    has_sse41_ = (cpu_info[2] & 0x00080000) != 0;
378    has_sse42_ = (cpu_info[2] & 0x00100000) != 0;
379    has_popcnt_ = (cpu_info[2] & 0x00800000) != 0;
380    has_osxsave_ = (cpu_info[2] & 0x08000000) != 0;
381    has_avx_ = (cpu_info[2] & 0x10000000) != 0;
382    has_fma3_ = (cpu_info[2] & 0x00001000) != 0;
383
384    if (family_ == 0x6) {
385      switch (model_) {
386        case 0x1c:  // SLT
387        case 0x26:
388        case 0x36:
389        case 0x27:
390        case 0x35:
391        case 0x37:  // SLM
392        case 0x4a:
393        case 0x4d:
394        case 0x4c:  // AMT
395        case 0x6e:
396          is_atom_ = true;
397      }
398    }
399  }
400
401  // There are separate feature flags for VEX-encoded GPR instructions.
402  if (num_ids >= 7) {
403    __cpuid(cpu_info, 7);
404    has_bmi1_ = (cpu_info[1] & 0x00000008) != 0;
405    has_bmi2_ = (cpu_info[1] & 0x00000100) != 0;
406  }
407
408  // Query extended IDs.
409  __cpuid(cpu_info, 0x80000000);
410  unsigned num_ext_ids = cpu_info[0];
411
412  // Interpret extended CPU feature information.
413  if (num_ext_ids > 0x80000000) {
414    __cpuid(cpu_info, 0x80000001);
415    has_lzcnt_ = (cpu_info[2] & 0x00000020) != 0;
416    // SAHF must be probed in long mode.
417    has_sahf_ = (cpu_info[2] & 0x00000001) != 0;
418  }
419
420#elif V8_HOST_ARCH_ARM
421
422#if V8_OS_LINUX
423
424  CPUInfo cpu_info;
425
426  // Extract implementor from the "CPU implementer" field.
427  char* implementer = cpu_info.ExtractField("CPU implementer");
428  if (implementer != NULL) {
429    char* end;
430    implementer_ = strtol(implementer, &end, 0);
431    if (end == implementer) {
432      implementer_ = 0;
433    }
434    delete[] implementer;
435  }
436
437  char* variant = cpu_info.ExtractField("CPU variant");
438  if (variant != NULL) {
439    char* end;
440    variant_ = strtol(variant, &end, 0);
441    if (end == variant) {
442      variant_ = -1;
443    }
444    delete[] variant;
445  }
446
447  // Extract part number from the "CPU part" field.
448  char* part = cpu_info.ExtractField("CPU part");
449  if (part != NULL) {
450    char* end;
451    part_ = strtol(part, &end, 0);
452    if (end == part) {
453      part_ = 0;
454    }
455    delete[] part;
456  }
457
458  // Extract architecture from the "CPU Architecture" field.
459  // The list is well-known, unlike the the output of
460  // the 'Processor' field which can vary greatly.
461  // See the definition of the 'proc_arch' array in
462  // $KERNEL/arch/arm/kernel/setup.c and the 'c_show' function in
463  // same file.
464  char* architecture = cpu_info.ExtractField("CPU architecture");
465  if (architecture != NULL) {
466    char* end;
467    architecture_ = strtol(architecture, &end, 10);
468    if (end == architecture) {
469      architecture_ = 0;
470    }
471    delete[] architecture;
472
473    // Unfortunately, it seems that certain ARMv6-based CPUs
474    // report an incorrect architecture number of 7!
475    //
476    // See http://code.google.com/p/android/issues/detail?id=10812
477    //
478    // We try to correct this by looking at the 'elf_platform'
479    // field reported by the 'Processor' field, which is of the
480    // form of "(v7l)" for an ARMv7-based CPU, and "(v6l)" for
481    // an ARMv6-one. For example, the Raspberry Pi is one popular
482    // ARMv6 device that reports architecture 7.
483    if (architecture_ == 7) {
484      char* processor = cpu_info.ExtractField("Processor");
485      if (HasListItem(processor, "(v6l)")) {
486        architecture_ = 6;
487      }
488      delete[] processor;
489    }
490
491    // elf_platform moved to the model name field in Linux v3.8.
492    if (architecture_ == 7) {
493      char* processor = cpu_info.ExtractField("model name");
494      if (HasListItem(processor, "(v6l)")) {
495        architecture_ = 6;
496      }
497      delete[] processor;
498    }
499  }
500
501  // Try to extract the list of CPU features from ELF hwcaps.
502  uint32_t hwcaps = ReadELFHWCaps();
503  if (hwcaps != 0) {
504    has_idiva_ = (hwcaps & HWCAP_IDIVA) != 0;
505    has_neon_ = (hwcaps & HWCAP_NEON) != 0;
506    has_vfp_ = (hwcaps & HWCAP_VFP) != 0;
507    has_vfp3_ = (hwcaps & (HWCAP_VFPv3 | HWCAP_VFPv3D16 | HWCAP_VFPv4)) != 0;
508    has_vfp3_d32_ = (has_vfp3_ && ((hwcaps & HWCAP_VFPv3D16) == 0 ||
509                                   (hwcaps & HWCAP_VFPD32) != 0));
510  } else {
511    // Try to fallback to "Features" CPUInfo field.
512    char* features = cpu_info.ExtractField("Features");
513    has_idiva_ = HasListItem(features, "idiva");
514    has_neon_ = HasListItem(features, "neon");
515    has_thumb2_ = HasListItem(features, "thumb2");
516    has_vfp_ = HasListItem(features, "vfp");
517    if (HasListItem(features, "vfpv3d16")) {
518      has_vfp3_ = true;
519    } else if (HasListItem(features, "vfpv3")) {
520      has_vfp3_ = true;
521      has_vfp3_d32_ = true;
522    }
523    delete[] features;
524  }
525
526  // Some old kernels will report vfp not vfpv3. Here we make an attempt
527  // to detect vfpv3 by checking for vfp *and* neon, since neon is only
528  // available on architectures with vfpv3. Checking neon on its own is
529  // not enough as it is possible to have neon without vfp.
530  if (has_vfp_ && has_neon_) {
531    has_vfp3_ = true;
532  }
533
534  // VFPv3 implies ARMv7, see ARM DDI 0406B, page A1-6.
535  if (architecture_ < 7 && has_vfp3_) {
536    architecture_ = 7;
537  }
538
539  // ARMv7 implies Thumb2.
540  if (architecture_ >= 7) {
541    has_thumb2_ = true;
542  }
543
544  // The earliest architecture with Thumb2 is ARMv6T2.
545  if (has_thumb2_ && architecture_ < 6) {
546    architecture_ = 6;
547  }
548
549  // We don't support any FPUs other than VFP.
550  has_fpu_ = has_vfp_;
551
552#elif V8_OS_QNX
553
554  uint32_t cpu_flags = SYSPAGE_ENTRY(cpuinfo)->flags;
555  if (cpu_flags & ARM_CPU_FLAG_V7) {
556    architecture_ = 7;
557    has_thumb2_ = true;
558  } else if (cpu_flags & ARM_CPU_FLAG_V6) {
559    architecture_ = 6;
560    // QNX doesn't say if Thumb2 is available.
561    // Assume false for the architectures older than ARMv7.
562  }
563  DCHECK(architecture_ >= 6);
564  has_fpu_ = (cpu_flags & CPU_FLAG_FPU) != 0;
565  has_vfp_ = has_fpu_;
566  if (cpu_flags & ARM_CPU_FLAG_NEON) {
567    has_neon_ = true;
568    has_vfp3_ = has_vfp_;
569#ifdef ARM_CPU_FLAG_VFP_D32
570    has_vfp3_d32_ = (cpu_flags & ARM_CPU_FLAG_VFP_D32) != 0;
571#endif
572  }
573  has_idiva_ = (cpu_flags & ARM_CPU_FLAG_IDIV) != 0;
574
575#endif  // V8_OS_LINUX
576
577#elif V8_HOST_ARCH_MIPS || V8_HOST_ARCH_MIPS64
578
579  // Simple detection of FPU at runtime for Linux.
580  // It is based on /proc/cpuinfo, which reveals hardware configuration
581  // to user-space applications.  According to MIPS (early 2010), no similar
582  // facility is universally available on the MIPS architectures,
583  // so it's up to individual OSes to provide such.
584  CPUInfo cpu_info;
585  char* cpu_model = cpu_info.ExtractField("cpu model");
586  has_fpu_ = HasListItem(cpu_model, "FPU");
587  delete[] cpu_model;
588#ifdef V8_HOST_ARCH_MIPS
589  is_fp64_mode_ = __detect_fp64_mode();
590  architecture_ = __detect_mips_arch_revision();
591#endif
592
593#elif V8_HOST_ARCH_ARM64
594
595  CPUInfo cpu_info;
596
597  // Extract implementor from the "CPU implementer" field.
598  char* implementer = cpu_info.ExtractField("CPU implementer");
599  if (implementer != NULL) {
600    char* end;
601    implementer_ = strtol(implementer, &end, 0);
602    if (end == implementer) {
603      implementer_ = 0;
604    }
605    delete[] implementer;
606  }
607
608  char* variant = cpu_info.ExtractField("CPU variant");
609  if (variant != NULL) {
610    char* end;
611    variant_ = strtol(variant, &end, 0);
612    if (end == variant) {
613      variant_ = -1;
614    }
615    delete[] variant;
616  }
617
618  // Extract part number from the "CPU part" field.
619  char* part = cpu_info.ExtractField("CPU part");
620  if (part != NULL) {
621    char* end;
622    part_ = strtol(part, &end, 0);
623    if (end == part) {
624      part_ = 0;
625    }
626    delete[] part;
627  }
628
629#elif V8_HOST_ARCH_PPC
630
631#ifndef USE_SIMULATOR
632#if V8_OS_LINUX
633  // Read processor info from /proc/self/auxv.
634  char* auxv_cpu_type = NULL;
635  FILE* fp = fopen("/proc/self/auxv", "r");
636  if (fp != NULL) {
637#if V8_TARGET_ARCH_PPC64
638    Elf64_auxv_t entry;
639#else
640    Elf32_auxv_t entry;
641#endif
642    for (;;) {
643      size_t n = fread(&entry, sizeof(entry), 1, fp);
644      if (n == 0 || entry.a_type == AT_NULL) {
645        break;
646      }
647      if (entry.a_type == AT_PLATFORM) {
648        auxv_cpu_type = reinterpret_cast<char*>(entry.a_un.a_val);
649        break;
650      }
651    }
652    fclose(fp);
653  }
654
655  part_ = -1;
656  if (auxv_cpu_type) {
657    if (strcmp(auxv_cpu_type, "power8") == 0) {
658      part_ = PPC_POWER8;
659    } else if (strcmp(auxv_cpu_type, "power7") == 0) {
660      part_ = PPC_POWER7;
661    } else if (strcmp(auxv_cpu_type, "power6") == 0) {
662      part_ = PPC_POWER6;
663    } else if (strcmp(auxv_cpu_type, "power5") == 0) {
664      part_ = PPC_POWER5;
665    } else if (strcmp(auxv_cpu_type, "ppc970") == 0) {
666      part_ = PPC_G5;
667    } else if (strcmp(auxv_cpu_type, "ppc7450") == 0) {
668      part_ = PPC_G4;
669    } else if (strcmp(auxv_cpu_type, "pa6t") == 0) {
670      part_ = PPC_PA6T;
671    }
672  }
673
674#elif V8_OS_AIX
675  switch (_system_configuration.implementation) {
676    case POWER_8:
677      part_ = PPC_POWER8;
678      break;
679    case POWER_7:
680      part_ = PPC_POWER7;
681      break;
682    case POWER_6:
683      part_ = PPC_POWER6;
684      break;
685    case POWER_5:
686      part_ = PPC_POWER5;
687      break;
688  }
689#endif  // V8_OS_AIX
690#endif  // !USE_SIMULATOR
691#endif  // V8_HOST_ARCH_PPC
692}
693
694}  // namespace base
695}  // namespace v8
696