Changes between Version 10 and Version 11 of Orio/TuneSpecs

Timestamp:

06/13/08 09:04:28 (15 years ago)

Author:

hartono

Comment:

--

Orio/TuneSpecs

@@ -96 +96 @@
 One prerequisite of a user-provided initialization program is that the input variables’ initializations must be enclosed inside a function named `init_input_vars`; otherwise, Orio will report an error message.
 
-== Overriding the Performance Testing Code ==
+== Extending the Performance Testing Code ==
 
-''Under construction''
+First, let us look at the basic C skeleton code used by Orio to measure the performance of the optimized code.
 
+{{{
+#include <stdio.h> 
+#include <stdlib.h> 
+#include <sys/time.h> 
+
+/*@ global @*/ 
+
+double rtclock() 
+{ 
+  struct timezone tzp; 
+  struct timeval tp; 
+  int stat; 
+  gettimeofday(&tp, &tzp); 
+  return (tp.tv_sec + tp.tv_usec*1.0e-6); 
+} 
+
+int main() 
+{ 
+  /*@ prologue @*/ 
+
+  double orio_t_start=0, orio_t_end=0, orio_t_total=0; 
+  int orio_i; 
+
+  for (orio_i=0; orio_i<REPS; orio_i++) 
+  { 
+    orio_t_start = rtclock(); 
+     
+    /*@ tested code @*/ 
+
+    orio_t_end = rtclock(); 
+    orio_t_total += orio_t_end - orio_t_start; 
+  } 
+   
+  orio_t_total = orio_t_total / REPS; 
+  printf("%f\n", orio_t_total); 
+   
+  /*@ epilogue @*/ 
+
+  return 0; 
+}
+}}}
+
+Four important tags exist in the skeleton code, each with its own special purpose. The '`/*@ global @*/`' tag is used by the driver to place global declarations such as input variable declarations and the initialization function of the input arrays. The ‘`/*@ prologue @*/`’ tag is the spot where to dynamically allocate memory space for input arrays and to call the function that initializes all input variables. The ‘`/*@ tested code @*/`’ tag designates the location of the code tested for its performance. And the last tag ‘`/*@ epilogue @*/`’ remains unused until now, but it is kept for potential development in the future.
+
+From the skeleton code, it can also be observed that Orio simply uses elapsed time as its performance metric through the standard C’s `gettimeofday` function. As a part of our future plans, we intend to employ a performance counter tool, such as TAO and PAPI, to facilitate a finer grained performance measurement (e.g. the number of processor clock cycles).
+