Update the tcmalloc vendor branch to r144 (gperftools 2.0), and README.chromium.

third_party/tcmalloc/vendor/src/base/cycleclock.h

 // Copyright (c) 2004, Google Inc.
 // All rights reserved.
 // 
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 // 
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
@@ skipping 29 matching lines @@
 // Also, in some out of order CPU implementations, the CycleClock is not 
 // serializing. So if you're trying to count at cycles granularity, your
 // data might be inaccurate due to out of order instruction execution.
 // ----------------------------------------------------------------------
 
 #ifndef GOOGLE_BASE_CYCLECLOCK_H_
 #define GOOGLE_BASE_CYCLECLOCK_H_
 
 #include "base/basictypes.h"   // make sure we get the def for int64
 #include "base/arm_instruction_set_select.h"
+// base/sysinfo.h is really big and we don't want to include it unless
+// it is necessary.
+#if defined(__arm__) || defined(__mips__)
+# include "base/sysinfo.h"
+#endif
 #if defined(__MACH__) && defined(__APPLE__)
 # include <mach/mach_time.h>
 #endif
 // For MSVC, we want to use '_asm rdtsc' when possible (since it works
 // with even ancient MSVC compilers), and when not possible the
 // __rdtsc intrinsic, declared in <intrin.h>.  Unfortunately, in some
 // environments, <windows.h> and <intrin.h> have conflicting
 // declarations of some other intrinsics, breaking compilation.
 // Therefore, we simply declare __rdtsc ourselves. See also
 // http://connect.microsoft.com/VisualStudio/feedback/details/262047
 #if defined(_MSC_VER) && !defined(_M_IX86)
 extern "C" uint64 __rdtsc();
 #pragma intrinsic(__rdtsc)
 #endif
-#ifdef ARMV3
+#if defined(ARMV3) || defined(__mips__)
 #include <sys/time.h>
 #endif
 
 // NOTE: only i386 and x86_64 have been well tested.
 // PPC, sparc, alpha, and ia64 are based on
 //    http://peter.kuscsik.com/wordpress/?p=14
 // with modifications by m3b.  See also
 //    https://setisvn.ssl.berkeley.edu/svn/lib/fftw-3.0.1/kernel/cycle.h
 struct CycleClock {
   // This should return the number of cycles since power-on.  Thread-safe.
@@ skipping 42 matching lines @@
     // the code is being compiled with a non-ancient compiler.
     _asm rdtsc
 #elif defined(_MSC_VER)
     return __rdtsc();
 #elif defined(ARMV3)
 #if defined(ARMV6)  // V6 is the earliest arch that has a standard cyclecount
     uint32 pmccntr;
     uint32 pmuseren;
     uint32 pmcntenset;
     // Read the user mode perf monitor counter access permissions.
-    asm("mrc p15, 0, %0, c9, c14, 0" : "=r" (pmuseren));
+    asm volatile ("mrc p15, 0, %0, c9, c14, 0" : "=r" (pmuseren));
     if (pmuseren & 1) {  // Allows reading perfmon counters for user mode code.
-      asm("mrc p15, 0, %0, c9, c12, 1" : "=r" (pmcntenset));
+      asm volatile ("mrc p15, 0, %0, c9, c12, 1" : "=r" (pmcntenset));
       if (pmcntenset & 0x80000000ul) {  // Is it counting?
-        asm("mrc p15, 0, %0, c9, c13, 0" : "=r" (pmccntr));
+        asm volatile ("mrc p15, 0, %0, c9, c13, 0" : "=r" (pmccntr));
         // The counter is set up to count every 64th cycle
         return static_cast<int64>(pmccntr) * 64;  // Should optimize to << 6
       }
     }
 #endif
     struct timeval tv;
     gettimeofday(&tv, NULL);
-    return static_cast<int64>(tv.tv_sec) * 1000000 + tv.tv_usec;
+    return static_cast<int64>((tv.tv_sec + tv.tv_usec * 0.000001)
+                              * CyclesPerSecond());
+#elif defined(__mips__)
+    // mips apparently only allows rdtsc for superusers, so we fall
+    // back to gettimeofday.  It's possible clock_gettime would be better.
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    return static_cast<int64>((tv.tv_sec + tv.tv_usec * 0.000001)
+                              * CyclesPerSecond());
 #else
 // The soft failover to a generic implementation is automatic only for ARM.
 // For other platforms the developer is expected to make an attempt to create
 // a fast implementation and use generic version if nothing better is available.
 #error You need to define CycleTimer for your O/S and CPU
 #endif
   }
 };
 
 
 #endif  // GOOGLE_BASE_CYCLECLOCK_H_