+uint32_t perf_start_count, perf_interval_count;
+
+#ifdef __WATCOMC__
+void perf_start(void);
+#pragma aux perf_start = \
+ "rdtsc" \
+ "mov [perf_start_count], eax" \
+ modify[eax edx];
+
+void perf_end(void);
+#pragma aux perf_end = \
+ "rdtsc" \
+ "sub eax, [perf_start_count]" \
+ "mov [perf_interval_count], eax" \
+ modify [eax edx];
+#endif
+
+#ifdef __GNUC__
+#define perf_start() asm volatile ( \
+ "rdtsc\n" \
+ "mov %%eax, %0\n" \
+ : "=m"(perf_start_count) :: "%eax", "%edx")
+
+#define perf_end() asm volatile ( \
+ "rdtsc\n" \
+ "sub %1, %%eax\n" \
+ "mov %%eax, %0\n" \
+ : "=m"(perf_interval_count) \
+ : "m"(perf_start_count) \
+ : "%eax", "%edx")
+#endif
+
+#ifdef _MSC_VER
+#define perf_start() \
+ do { \
+ __asm { \
+ rdtsc \
+ mov [perf_start_count], eax \
+ } \
+ } while(0)
+
+#define perf_end() \
+ do { \
+ __asm { \
+ rdtsc \
+ sub eax, [perf_start_count] \
+ mov [perf_interval_count], eax \
+ } \
+ } while(0)
+#endif
+