Revert 126020 - Experiment for updating the tcmalloc chromium branch to r144 (gperftools 2.0).

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

Index: third_party/tcmalloc/chromium/src/base/cycleclock.h
===================================================================
--- third_party/tcmalloc/chromium/src/base/cycleclock.h	(revision 126022)
+++ third_party/tcmalloc/chromium/src/base/cycleclock.h	(working copy)
@@ -47,30 +47,21 @@
 
 #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.
+// For MSVC, we want 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)
+#if defined(_MSC_VER)
 extern "C" uint64 __rdtsc();
 #pragma intrinsic(__rdtsc)
 #endif
-#if defined(ARMV3) || defined(__mips__)
 #ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif
-#endif
 
 // NOTE: only i386 and x86_64 have been well tested.
 // PPC, sparc, alpha, and ia64 are based on
@@ -117,12 +108,6 @@
     int64 itc;
     asm("mov %0 = ar.itc" : "=r" (itc));
     return itc;
-#elif defined(_MSC_VER) && defined(_M_IX86)
-    // Older MSVC compilers (like 7.x) don't seem to support the
-    // __rdtsc intrinsic properly, so I prefer to use _asm instead
-    // when I know it will work.  Otherwise, I'll use __rdtsc and hope
-    // the code is being compiled with a non-ancient compiler.
-    _asm rdtsc
 #elif defined(_MSC_VER)
     return __rdtsc();
 #elif defined(ARMV3)
@@ -131,11 +116,11 @@
     uint32 pmuseren;
     uint32 pmcntenset;
     // Read the user mode perf monitor counter access permissions.
-    asm volatile ("mrc p15, 0, %0, c9, c14, 0" : "=r" (pmuseren));
+    asm("mrc p15, 0, %0, c9, c14, 0" : "=r" (pmuseren));
     if (pmuseren & 1) {  // Allows reading perfmon counters for user mode code.
-      asm volatile ("mrc p15, 0, %0, c9, c12, 1" : "=r" (pmcntenset));
+      asm("mrc p15, 0, %0, c9, c12, 1" : "=r" (pmcntenset));
       if (pmcntenset & 0x80000000ul) {  // Is it counting?
-        asm volatile ("mrc p15, 0, %0, c9, c13, 0" : "=r" (pmccntr));
+        asm("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
       }
@@ -143,15 +128,7 @@
 #endif
     struct timeval tv;
     gettimeofday(&tv, NULL);
-    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());
+    return static_cast<int64>(tv.tv_sec) * 1000000 + tv.tv_usec;
 #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