1 files changed, 29 insertions, 2 deletions
diff --git a/deps/v8/test/cctest/compiler/test-basic-block-profiler.cc b/deps/v8/test/cctest/compiler/test-basic-block-profiler.cc
index 795c1f1bd2..561f9a68b7 100644
--- a/deps/v8/test/cctest/compiler/test-basic-block-profiler.cc
+++ b/deps/v8/test/cctest/compiler/test-basic-block-profiler.cc
@@ -28,9 +28,21 @@ class BasicBlockProfilerTest : public RawMachineAssemblerTester<int32_t> {
     CHECK_NE(0, static_cast<int>(l->size()));
     const BasicBlockProfilerData* data = l->back().get();
     CHECK_EQ(static_cast<int>(size), static_cast<int>(data->n_blocks()));
-    const double* counts = data->counts();
+    const uint32_t* counts = data->counts();
     for (size_t i = 0; i < size; ++i) {
-      CHECK_EQ(static_cast<double>(expected[i]), counts[i]);
+      CHECK_EQ(expected[i], counts[i]);
+    }
+  }
+
+  void SetCounts(size_t size, uint32_t* new_counts) {
+    const BasicBlockProfiler::DataList* l =
+        BasicBlockProfiler::Get()->data_list();
+    CHECK_NE(0, static_cast<int>(l->size()));
+    BasicBlockProfilerData* data = l->back().get();
+    CHECK_EQ(static_cast<int>(size), static_cast<int>(data->n_blocks()));
+    uint32_t* counts = const_cast<uint32_t*>(data->counts());
+    for (size_t i = 0; i < size; ++i) {
+      counts[i] = new_counts[i];
     }
   }
 };
@@ -73,6 +85,21 @@ TEST(ProfileDiamond) {
     uint32_t expected[] = {2, 1, 1, 1, 1, 2};
     m.Expect(arraysize(expected), expected);
   }
+
+  // Set the counters very high, to verify that they saturate rather than
+  // overflowing.
+  uint32_t near_overflow[] = {UINT32_MAX - 1, UINT32_MAX - 1, UINT32_MAX - 1,
+                              UINT32_MAX - 1, UINT32_MAX - 1, UINT32_MAX - 1};
+  m.SetCounts(arraysize(near_overflow), near_overflow);
+  m.Expect(arraysize(near_overflow), near_overflow);
+
+  m.Call(0);
+  m.Call(0);
+  {
+    uint32_t expected[] = {UINT32_MAX,     UINT32_MAX,     UINT32_MAX,
+                           UINT32_MAX - 1, UINT32_MAX - 1, UINT32_MAX};
+    m.Expect(arraysize(expected), expected);
+  }
 }