Add more tests for qselect

Author: Raghuveer Devulapalli

tests/test_qselect.hpp

@@ -5,7 +5,7 @@ class avx512_select : public ::testing::Test {
 };
 TYPED_TEST_SUITE_P(avx512_select);
 
-TYPED_TEST_P(avx512_select, test_arrsizes)
+TYPED_TEST_P(avx512_select, test_random)
 {
     if (cpu_has_avx512bw()) {
         if ((sizeof(TypeParam) == 2) && (!cpu_has_avx512_vbmi2())) {
@@ -48,4 +48,47 @@ TYPED_TEST_P(avx512_select, test_arrsizes)
     }
 }
 
-REGISTER_TYPED_TEST_SUITE_P(avx512_select, test_arrsizes);
+TYPED_TEST_P(avx512_select, test_small_range)
+{
+    if (cpu_has_avx512bw()) {
+        if ((sizeof(TypeParam) == 2) && (!cpu_has_avx512_vbmi2())) {
+            GTEST_SKIP() << "Skipping this test, it requires avx512_vbmi2";
+        }
+        std::vector<int64_t> arrsizes;
+        for (int64_t ii = 0; ii < 1024; ++ii) {
+            arrsizes.push_back(ii);
+        }
+        std::vector<TypeParam> arr;
+        std::vector<TypeParam> sortedarr;
+        std::vector<TypeParam> psortedarr;
+        for (size_t ii = 0; ii < arrsizes.size(); ++ii) {
+            /* Random array */
+            arr = get_uniform_rand_array<TypeParam>(arrsizes[ii], 20, 1);
+            sortedarr = arr;
+            /* Sort with std::sort for comparison */
+            std::sort(sortedarr.begin(), sortedarr.end());
+            for (size_t k = 0; k < arr.size(); ++k) {
+                psortedarr = arr;
+                avx512_qselect<TypeParam>(psortedarr.data(), k, psortedarr.size());
+                /* index k is correct */
+                ASSERT_EQ(sortedarr[k], psortedarr[k]);
+                /* Check left partition */
+                for (size_t jj = 0; jj < k; jj++) {
+                    ASSERT_LE(psortedarr[jj], psortedarr[k]);
+                }
+                /* Check right partition */
+                for (size_t jj = k+1; jj < arr.size(); jj++) {
+                    ASSERT_GE(psortedarr[jj], psortedarr[k]);
+                }
+                psortedarr.clear();
+            }
+            arr.clear();
+            sortedarr.clear();
+        }
+    }
+    else {
+        GTEST_SKIP() << "Skipping this test, it requires avx512bw";
+    }
+}
+
+REGISTER_TYPED_TEST_SUITE_P(avx512_select, test_random, test_small_range);