[x64] Introduce BMI instructions.

src/base/cpu.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/base/cpu.h"
 
 #if V8_LIBC_MSVCRT
 #include <intrin.h>  // __cpuid()
 #endif
 #if V8_OS_LINUX
@@ skipping 34 matching lines @@
 namespace base {
 
 #if defined(__pnacl__)
 // Portable host shouldn't do feature detection.
 #elif V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64
 
 // Define __cpuid() for non-MSVC libraries.
 #if !V8_LIBC_MSVCRT
 
 static V8_INLINE void __cpuid(int cpu_info[4], int info_type) {
+// Clear ecx to align with __cpuid() of MSVC:
+// https://msdn.microsoft.com/en-us/library/hskdteyh.aspx
 #if defined(__i386__) && defined(__pic__)
   // Make sure to preserve ebx, which contains the pointer
   // to the GOT in case we're generating PIC.
-  __asm__ volatile (
-    "mov %%ebx, %%edi\n\t"
-    "cpuid\n\t"
-    "xchg %%edi, %%ebx\n\t"
-    : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
-    : "a"(info_type)
-  );
+  __asm__ volatile(
+      "mov %%ebx, %%edi\n\t"
+      "cpuid\n\t"
+      "xchg %%edi, %%ebx\n\t"
+      : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]),
+        "=d"(cpu_info[3])
+      : "a"(info_type), "c"(0));
 #else
-  __asm__ volatile (
-    "cpuid \n\t"
-    : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
-    : "a"(info_type)
-  );
+  __asm__ volatile("cpuid \n\t"
+                   : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]),
+                     "=d"(cpu_info[3])
+                   : "a"(info_type), "c"(0));
 #endif  // defined(__i386__) && defined(__pic__)
 }
 
 #endif  // !V8_LIBC_MSVCRT
 
 #elif V8_HOST_ARCH_ARM || V8_HOST_ARCH_ARM64 \
     || V8_HOST_ARCH_MIPS || V8_HOST_ARCH_MIPS64
 
 #if V8_OS_LINUX
 
@@ skipping 237 matching lines @@
       has_sse_(false),
       has_sse2_(false),
       has_sse3_(false),
       has_ssse3_(false),
       has_sse41_(false),
       has_sse42_(false),
       is_atom_(false),
       has_osxsave_(false),
       has_avx_(false),
       has_fma3_(false),
+      has_bmi1_(false),
+      has_bmi2_(false),
+      has_lzcnt_(false),
+      has_popcnt_(false),
       has_idiva_(false),
       has_neon_(false),
       has_thumb2_(false),
       has_vfp_(false),
       has_vfp3_(false),
       has_vfp3_d32_(false),
       is_fp64_mode_(false) {
   memcpy(vendor_, "Unknown", 8);
 #if V8_OS_NACL
 // Portable host shouldn't do feature detection.
@@ skipping 26 matching lines @@
     ext_family_ = (cpu_info[0] >> 20) & 0xff;
     has_fpu_ = (cpu_info[3] & 0x00000001) != 0;
     has_cmov_ = (cpu_info[3] & 0x00008000) != 0;
     has_mmx_ = (cpu_info[3] & 0x00800000) != 0;
     has_sse_ = (cpu_info[3] & 0x02000000) != 0;
     has_sse2_ = (cpu_info[3] & 0x04000000) != 0;
     has_sse3_ = (cpu_info[2] & 0x00000001) != 0;
     has_ssse3_ = (cpu_info[2] & 0x00000200) != 0;
     has_sse41_ = (cpu_info[2] & 0x00080000) != 0;
     has_sse42_ = (cpu_info[2] & 0x00100000) != 0;
+    has_popcnt_ = (cpu_info[2] & 0x00800000) != 0;
     has_osxsave_ = (cpu_info[2] & 0x08000000) != 0;
     has_avx_ = (cpu_info[2] & 0x10000000) != 0;
     has_fma3_ = (cpu_info[2] & 0x00001000) != 0;
 
     if (family_ == 0x6) {
       switch (model_) {
         case 0x1c:  // SLT
         case 0x26:
         case 0x36:
         case 0x27:
         case 0x35:
         case 0x37:  // SLM
         case 0x4a:
         case 0x4d:
         case 0x4c:  // AMT
         case 0x6e:
           is_atom_ = true;
       }
     }
   }
 
-#if V8_HOST_ARCH_IA32
-  // SAHF is always available in compat/legacy mode,
-  has_sahf_ = true;
-#else
+  // There are separate feature flags for VEX-encoded GPR instructions.
+  if (num_ids >= 7) {
+    __cpuid(cpu_info, 7);
+    has_bmi1_ = (cpu_info[1] & 0x00000008) != 0;
+    has_bmi2_ = (cpu_info[1] & 0x00000100) != 0;
+  }
+
   // Query extended IDs.
   __cpuid(cpu_info, 0x80000000);
   unsigned num_ext_ids = cpu_info[0];
 
   // Interpret extended CPU feature information.
   if (num_ext_ids > 0x80000000) {
     __cpuid(cpu_info, 0x80000001);
+    has_lzcnt_ = (cpu_info[2] & 0x00000020) != 0;
     // SAHF must be probed in long mode.
     has_sahf_ = (cpu_info[2] & 0x00000001) != 0;
   }
-#endif
 
 #elif V8_HOST_ARCH_ARM
 
 #if V8_OS_LINUX
 
   CPUInfo cpu_info;
 
   // Extract implementor from the "CPU implementer" field.
   char* implementer = cpu_info.ExtractField("CPU implementer");
   if (implementer != NULL) {
@@ skipping 256 matching lines @@
     case POWER_5:
       part_ = PPC_POWER5;
       break;
   }
 #endif  // V8_OS_AIX
 #endif  // !USE_SIMULATOR
 #endif  // V8_HOST_ARCH_PPC
 }
 
 } }  // namespace v8::base