diff --git a/openmp/tools/archer/ompt-tsan.cpp b/openmp/tools/archer/ompt-tsan.cpp
--- a/openmp/tools/archer/ompt-tsan.cpp
+++ b/openmp/tools/archer/ompt-tsan.cpp
@@ -15,18 +15,18 @@
 #define __STDC_FORMAT_MACROS
 #endif
 
+#include <algorithm>
 #include <atomic>
 #include <cassert>
 #include <cstdlib>
 #include <cstring>
 #include <inttypes.h>
 #include <iostream>
+#include <list>
 #include <mutex>
 #include <sstream>
 #include <stack>
-#include <list>
 #include <string>
-#include <iostream>
 #include <unordered_map>
 #include <vector>
 
@@ -89,17 +89,26 @@
   TsanFlags(const char *env) : ignore_noninstrumented_modules(0) {
     if (env) {
       std::vector<std::string> tokens;
-      std::string token;
       std::string str(env);
-      std::istringstream iss(str);
-      while (std::getline(iss, token, ' '))
-        tokens.push_back(token);
+      auto end = str.end();
+      auto it = str.begin();
+      auto is_sep = [](char c) {
+        return c == ' ' || c == ',' || c == ':' || c == '\n' || c == '\t' ||
+               c == '\r';
+      };
+      while (it != end) {
+        auto next_it = std::find_if(it, end, is_sep);
+        tokens.emplace_back(it, next_it);
+        it = next_it;
+        if (it != end) {
+          ++it;
+        }
+      }
 
-      for (std::vector<std::string>::iterator it = tokens.begin();
-           it != tokens.end(); ++it) {
+      for (const auto &token : tokens) {
         // we are interested in ignore_noninstrumented_modules to print a
         // warning
-        if (sscanf(it->c_str(), "ignore_noninstrumented_modules=%d",
+        if (sscanf(token.c_str(), "ignore_noninstrumented_modules=%d",
                    &ignore_noninstrumented_modules))
           continue;
       }
diff --git a/openmp/tools/archer/tests/lit.cfg b/openmp/tools/archer/tests/lit.cfg
--- a/openmp/tools/archer/tests/lit.cfg
+++ b/openmp/tools/archer/tests/lit.cfg
@@ -93,6 +93,8 @@
 # Race Tests
 config.substitutions.append(("%libarcher-compile-and-run-race", \
     "%libarcher-compile && %libarcher-run-race"))
+config.substitutions.append(("%libarcher-compile-and-run-nosuppression", \
+                             "%libarcher-compile && %libarcher-run-nosuppression"))
 config.substitutions.append(("%libarcher-compile-and-run", \
                              "%libarcher-compile && %libarcher-run"))
 config.substitutions.append(("%libarcher-cxx-compile-and-run", \
@@ -102,13 +104,15 @@
 config.substitutions.append(("%libarcher-compile", \
                              "%clang-archer %openmp_flags %archer_flags %flags %s -o %t" + libs))
 config.substitutions.append(("%libarcher-run-race", "%suppression %deflake %t 2>&1 | tee %t.log"))
+config.substitutions.append(("%libarcher-run-nosuppression", "%nosuppression %t 2>&1 | tee %t.log"))
 config.substitutions.append(("%libarcher-run", "%suppression %t 2>&1 | tee %t.log"))
 config.substitutions.append(("%clang-archerXX", config.test_cxx_compiler))
 config.substitutions.append(("%clang-archer", config.test_c_compiler))
 config.substitutions.append(("%openmp_flags", config.test_openmp_flags))
 config.substitutions.append(("%archer_flags", config.archer_flags))
 config.substitutions.append(("%flags", config.test_flags))
-config.substitutions.append(("%suppression", "env TSAN_OPTIONS='ignore_noninstrumented_modules=1'"))
+config.substitutions.append(("%nosuppression", "env TSAN_OPTIONS='ignore_noninstrumented_modules=0'"))
+config.substitutions.append(("%suppression", "env TSAN_OPTIONS='ignore_noninstrumented_modules=0:ignore_noninstrumented_modules=1'"))
 config.substitutions.append(("%deflake", os.path.join(os.path.dirname(__file__), "deflake.bash")))
 
 config.substitutions.append(("FileCheck", config.test_filecheck))
diff --git a/openmp/tools/archer/tests/parallel/parallel-simple.c b/openmp/tools/archer/tests/parallel/parallel-nosuppression.c
copy from openmp/tools/archer/tests/parallel/parallel-simple.c
copy to openmp/tools/archer/tests/parallel/parallel-nosuppression.c
--- a/openmp/tools/archer/tests/parallel/parallel-simple.c
+++ b/openmp/tools/archer/tests/parallel/parallel-nosuppression.c
@@ -1,5 +1,5 @@
 /*
- * parallel-simple.c -- Archer testcase
+ * parallel-nosuppression.c -- Archer testcase
  */
 
 //===----------------------------------------------------------------------===//
@@ -12,7 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 
-// RUN: %libarcher-compile-and-run | FileCheck %s
+// RUN: %libarcher-compile-and-run-nosuppression | FileCheck %s
 // REQUIRES: tsan
 #include <omp.h>
 #include <stdio.h>
@@ -36,4 +36,5 @@
 
 // CHECK-NOT: ThreadSanitizer: data race
 // CHECK-NOT: ThreadSanitizer: reported
+// CHECK: Warning: please export TSAN_OPTIONS
 // CHECK: DONE
diff --git a/openmp/tools/archer/tests/parallel/parallel-simple.c b/openmp/tools/archer/tests/parallel/parallel-simple.c
--- a/openmp/tools/archer/tests/parallel/parallel-simple.c
+++ b/openmp/tools/archer/tests/parallel/parallel-simple.c
@@ -36,4 +36,5 @@
 
 // CHECK-NOT: ThreadSanitizer: data race
 // CHECK-NOT: ThreadSanitizer: reported
+// CHECK-NOT: Warning: please export TSAN_OPTIONS
 // CHECK: DONE