diff --git a/coreconf/check_cc_clang.py b/coreconf/check_cc.py
similarity index 64%
rename from coreconf/check_cc_clang.py
rename to coreconf/check_cc.py
index 4b95411954..6d7e380961 100644
--- a/coreconf/check_cc_clang.py
+++ b/coreconf/check_cc.py
@@ -5,17 +5,18 @@
 import sys
 
 def main():
-    if sys.platform == 'win32':
+    if sys.platform == 'win32' or len(sys.argv) < 2:
         print(0)
     else:
         cc = os.environ.get('CC', 'cc')
         try:
-            cc_is_clang = 'clang' in subprocess.check_output(
+            cc_is_arg = sys.argv[1] in subprocess.check_output(
               [cc, '--version'], universal_newlines=True)
         except OSError:
             # We probably just don't have CC/cc.
-            cc_is_clang = False
-        print(int(cc_is_clang))
+            cc_is_arg = False
+        print(int(cc_is_arg))
 
 if __name__ == '__main__':
     main()
+
diff --git a/coreconf/config.gypi b/coreconf/config.gypi
index 1dde15fe3b..a0d381f0c3 100644
--- a/coreconf/config.gypi
+++ b/coreconf/config.gypi
@@ -64,10 +64,15 @@
           ],
         }],
         ['"<(GENERATOR)"=="ninja"', {
-          'cc_is_clang%': '<!(<(python) <(DEPTH)/coreconf/check_cc_clang.py)',
+          'cc_is_clang%': '<!(<(python) <(DEPTH)/coreconf/check_cc.py clang)',
         }, {
           'cc_is_clang%': '0',
         }],
+        ['"<(GENERATOR)"=="ninja"', {
+          'cc_is_gcc%': '<!(<(python) <(DEPTH)/coreconf/check_cc.py gcc)',
+        }, {
+          'cc_is_gcc%': '0',
+        }],
       ],
     },
     # Copy conditionally-set variables out one scope.
@@ -86,6 +91,7 @@
     'dll_suffix': '<(dll_suffix)',
     'freebl_name': '<(freebl_name)',
     'cc_is_clang%': '<(cc_is_clang)',
+    'cc_is_gcc%': '<(cc_is_gcc)',
     'cc_use_gnu_ld%': '<(cc_use_gnu_ld)',
     # Some defaults
     'disable_tests%': 0,
diff --git a/gtests/freebl_gtest/freebl_gtest.gyp b/gtests/freebl_gtest/freebl_gtest.gyp
index 21a87c557c..bc9bd95843 100644
--- a/gtests/freebl_gtest/freebl_gtest.gyp
+++ b/gtests/freebl_gtest/freebl_gtest.gyp
@@ -40,6 +40,13 @@
         'freebl_gtest_deps',
         '<(DEPTH)/exports.gyp:nss_exports',
       ],
+      'conditions': [
+      [ 'cc_is_gcc==1 and (target_arch=="ia32" or target_arch=="x64")', {
+         'cflags_cc': [
+          '-msse2',
+          ],
+        }],
+      ],
     },
     {
       'target_name': 'prng_gtest',
diff --git a/gtests/freebl_gtest/mpi_unittest.cc b/gtests/freebl_gtest/mpi_unittest.cc
index 2ccb8c351a..b0944975ef 100644
--- a/gtests/freebl_gtest/mpi_unittest.cc
+++ b/gtests/freebl_gtest/mpi_unittest.cc
@@ -6,6 +6,7 @@
 
 #include <stdint.h>
 #include <string.h>
+#include <memory>
 
 #ifdef __MACH__
 #include <mach/clock.h>
@@ -27,7 +28,7 @@ void gettime(struct timespec* tp) {
   tp->tv_sec = mts.tv_sec;
   tp->tv_nsec = mts.tv_nsec;
 #else
-  clock_gettime(CLOCK_MONOTONIC, tp);
+  ASSERT_NE(0, timespec_get(tp, TIME_UTC));
 #endif
 }
 
@@ -84,8 +85,9 @@ class MPITest : public ::testing::Test {
     mp_int a;
     ASSERT_EQ(MP_OKAY, mp_init(&a));
     ASSERT_EQ(MP_OKAY, mp_read_unsigned_octets(&a, ref.data(), ref.size()));
-    uint8_t buf[len];
-    ASSERT_EQ(MP_OKAY, mp_to_fixlen_octets(&a, buf, len));
+    std::unique_ptr<uint8_t[]> buf(new uint8_t[len]);
+    ASSERT_NE(buf, nullptr);
+    ASSERT_EQ(MP_OKAY, mp_to_fixlen_octets(&a, buf.get(), len));
     size_t compare;
     if (len > ref.size()) {
       for (size_t i = 0; i < len - ref.size(); ++i) {
@@ -96,9 +98,9 @@ class MPITest : public ::testing::Test {
       compare = len;
     }
     dump("value", ref.data(), ref.size());
-    dump("output", buf, len);
-    ASSERT_EQ(0, memcmp(buf + len - compare, ref.data() + ref.size() - compare,
-                        compare))
+    dump("output", buf.get(), len);
+    ASSERT_EQ(0, memcmp(buf.get() + len - compare,
+                        ref.data() + ref.size() - compare, compare))
         << "comparing " << compare << " octets";
     mp_clear(&a);
   }
diff --git a/gtests/freebl_gtest/rsa_unittest.cc b/gtests/freebl_gtest/rsa_unittest.cc
index a1453168f9..9a6a9c11fd 100644
--- a/gtests/freebl_gtest/rsa_unittest.cc
+++ b/gtests/freebl_gtest/rsa_unittest.cc
@@ -5,6 +5,7 @@
 #include "gtest/gtest.h"
 
 #include <stdint.h>
+#include <memory>
 
 #include "blapi.h"
 #include "secitem.h"
diff --git a/nss.gyp b/nss.gyp
index eb4d63095d..419d4f2ad9 100644
--- a/nss.gyp
+++ b/nss.gyp
@@ -198,6 +198,7 @@
             'gtests/certdb_gtest/certdb_gtest.gyp:certdb_gtest',
             'gtests/freebl_gtest/freebl_gtest.gyp:prng_gtest',
             'gtests/freebl_gtest/freebl_gtest.gyp:blake2b_gtest',
+            'gtests/freebl_gtest/freebl_gtest.gyp:freebl_gtest',
             'gtests/mozpkix_gtest/mozpkix_gtest.gyp:mozpkix_gtest',
             'gtests/nss_bogo_shim/nss_bogo_shim.gyp:nss_bogo_shim',
             'gtests/pk11_gtest/pk11_gtest.gyp:pk11_gtest',