1 files changed, 71 insertions, 0 deletions
diff --git a/searchlib/src/tests/alignment/alignment_test.cpp b/searchlib/src/tests/alignment/alignment_test.cpp
new file mode 100644
index 00000000000..3c6906f45bf
--- /dev/null
+++ b/searchlib/src/tests/alignment/alignment_test.cpp
@@ -0,0 +1,71 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+#include <vespa/log/log.h>
+LOG_SETUP("alignment_test");
+
+#include <sys/resource.h>
+#include <sys/time.h>
+#include <vespa/vespalib/testkit/testapp.h>
+#include <vespa/vespalib/util/size_literals.h>
+#include <vespa/vespalib/util/memory.h>
+
+using vespalib::Unaligned;
+
+struct Timer {
+    rusage usage;
+    void start() {
+        getrusage(RUSAGE_SELF, &usage);
+    }
+    double stop() {
+        rusage tmp;
+        getrusage(RUSAGE_SELF, &tmp);
+        double startMs = (((double)usage.ru_utime.tv_sec) * 1000.0)
+                         + (((double)usage.ru_utime.tv_usec) / 1000.0);
+        double stopMs = (((double)tmp.ru_utime.tv_sec) * 1000.0)
+                        + (((double)tmp.ru_utime.tv_usec) / 1000.0);
+        return (stopMs - startMs);
+    }
+};
+
+TEST_SETUP(Test);
+
+double
+timeAccess(void *bufp, uint32_t len, double &sum)
+{
+    auto buf = Unaligned<double>::ptr(bufp);
+    Timer timer;
+    timer.start();
+    for(uint32_t i = 0; i < 512_Ki; ++i) {
+        for (uint32_t j = 0; j < len; ++j) {
+            sum += buf[j];
+        }
+    }
+    double ret = timer.stop();
+    return ret;
+}
+
+int
+Test::Main()
+{
+    TEST_INIT("alignment_test");
+
+    uint32_t buf[129];
+    for (uint32_t i = 0; i < 129; ++i) {
+        buf[i] = i;
+    }
+
+    uintptr_t ptr = reinterpret_cast<uintptr_t>(&buf[0]);
+    bool aligned = (ptr % sizeof(double) == 0);
+
+    double foo = 0, bar = 0;
+    printf(aligned ? "ALIGNED\n" : "UNALIGNED\n");
+    printf("warmup time = %.2f\n", timeAccess(reinterpret_cast<void*>(&buf[0]), 64, foo));
+    printf("real   time = %.2f\n", timeAccess(reinterpret_cast<void*>(&buf[0]), 64, bar));
+    EXPECT_EQUAL(foo, bar);
+
+    printf(!aligned ? "ALIGNED\n" : "UNALIGNED\n");
+    printf("warmup time = %.2f\n", timeAccess(reinterpret_cast<void*>(&buf[1]), 64, foo));
+    printf("real   time = %.2f\n", timeAccess(reinterpret_cast<void*>(&buf[1]), 64, bar));
+    EXPECT_EQUAL(foo, bar);
+
+    TEST_DONE();
+}