rocrtst: Fix RoundToPowerOf2 function

Compiler behavior is undefined if the right operand is negative,
or greater than or equal to the width of the promoted left operand.
For release builds with address sanitizer enabled, this compiler
optimization behavior leads to unsupported queue size value since
current method shifts till 128 bits on a 64 bit value.

Change-Id: Iddcc15b43d2331bc8bf5fc3aa4725f76844655ec
Signed-off-by: Sreekant Somasekharan <sreekant.somasekharan@amd.com>

rocrtst/common/helper_funcs.cc

@@ -103,16 +103,15 @@ int FillRandom(T* arrayPtr,
 }
 
 uint64_t RoundToPowerOf2(uint64_t val) {
-  int bytes = sizeof(uint64_t);
-
   val--;
-
-  for (int i = 0; i < bytes; i++) {
-    val |= val >> (1 << i);
-  }
+  /*
+   * Shift with amount larger than the bit width can result in
+   * undefined behavior by compiler for release builds.
+   * Shift till 32 bit only which is less than bit width of val.
+   */
+  for (int i = 1; i <= 32; i *= 2) val |= val >> i;
 
   val++;
-
   return val;
 }