Remove accidental use of RDTSCP with GMX_USE_RDTSCP=off

diff --git a/src/external/thread_mpi/include/thread_mpi/atomic/cycles.h b/src/external/thread_mpi/include/thread_mpi/atomic/cycles.h
index 203077c624401e99f61c313632bb8de21753ca74..51ccfef4c5225f1ce14878721ea63410c1e803d5 100644 (file)
--- a/src/external/thread_mpi/include/thread_mpi/atomic/cycles.h
+++ b/src/external/thread_mpi/include/thread_mpi/atomic/cycles.h
@@ -1,5 +1,5 @@
 /*
- * define GMX_USE_RDTSCP to use the serializing rdtscp instruction instead of rdtsc.
+ * define GMX_USE_RDTSCP=1 to use the serializing rdtscp instruction instead of rdtsc.
  * This is only supported on newer Intel/AMD hardware, but provides better accuracy.
  */
 
@@ -48,7 +48,7 @@ static __inline__ tMPI_Cycles_t tMPI_Cycles_read(void)
 typedef __int64 tMPI_Cycles_t;
 static __inline tMPI_Cycles_t tMPI_Cycles_read(void)
 {
-#ifdef GMX_USE_RDTSCP
+#if GMX_USE_RDTSCP
     unsigned int ui;
     return __rdtscp(&ui);
 #else