some tuning

examples_ptx/mergeSort/keyType.h

@@ -0,0 +1,3 @@
+#pragma once
+typedef float Key_t;
+typedef int   Val_t;

examples_ptx/mergeSort/mergeSort.cpp

@@ -30,8 +30,7 @@ static inline void progressbar (unsigned int x, unsigned int n, unsigned int w =
   cout << "]\r" << flush;
 }
 
-typedef float Key_t;
-typedef int   Val_t;
+#include "keyType.h"
 struct Key
 {
   Key_t key;

examples_ptx/mergeSort/mergeSort.ispc

@@ -1,5 +1,4 @@
-typedef float Key_t;
-typedef int   Val_t;
+#include "keyType.h"
 
 #define SAMPLE_STRIDE programCount