lib/profiler/get_tick.h

   1 #ifndef _PROFILER_GET_TICK_H_
   2 #define _PROFILER_GET_TICK_H_
   3
   4 #include "config.h"
   5
   6 #if USE_XPROF_STATS
   7
   8 #if !_SQUID_SOLARIS_
   9 typedef int64_t  hrtime_t;
  10 #endif
  11
  12 #if defined(__GNUC__) && ( defined(__i386) || defined(__i386__) )
  13 static inline hrtime_t
  14 get_tick(void)
  15 {
  16     hrtime_t regs;
  17
  18 asm volatile ("rdtsc":"=A" (regs));
  19     return regs;
  20     /* We need return value, we rely on CC to optimise out needless subf calls */
  21     /* Note that "rdtsc" is relatively slow OP and stalls the CPU pipes, so use it wisely */
  22 }
  23
  24 #elif defined(__GNUC__) && ( defined(__x86_64) || defined(__x86_64__) )
  25 static inline hrtime_t
  26 get_tick(void)
  27 {
  28     uint32_t lo, hi;
  29     // Based on an example in Wikipedia
  30     /* We cannot use "=A", since this would use %rax on x86_64 */
  31 asm volatile ("rdtsc" : "=a" (lo), "=d" (hi));
  32     return (hrtime_t)hi << 32 | lo;
  33 }
  34
  35 #elif defined(__GNUC__) && defined(__alpha)
  36 static inline hrtime_t
  37 get_tick(void)
  38 {
  39     hrtime_t regs;
  40
  41 asm volatile ("rpcc %0" : "=r" (regs));
  42     return regs;
  43 }
  44
  45 #elif defined(_M_IX86) && defined(_MSC_VER) /* x86 platform on Microsoft C Compiler ONLY */
  46 static __inline hrtime_t
  47 get_tick(void)
  48 {
  49     hrtime_t regs;
  50
  51     __asm {
  52         cpuid
  53         rdtsc
  54         mov eax,DWORD PTR regs[0]
  55         mov edx,DWORD PTR regs[4]
  56     }
  57     return regs;
  58 }
  59
  60 #else
  61 /* This CPU is unsupported. Short-circuit, no profiling here */
  62 #define get_tick() 0
  63 #undef USE_XPROF_STATS
  64 #define USE_XPROF_STATS 0
  65 #endif
  66
  67 #endif /* USE_XPROF_STATS */
  68 #endif /* _PROFILING_H_ */