[SYCL] Add bfloat16 'hello world' host test.

SYCL/BFloat16/bfloat_hw.cpp

@@ -0,0 +1,60 @@
+// RUN: %clangxx -fsycl %s -o %t.out
+// RUN: %t.out
+
+// "Hello world" bfloat16 test which checks conversion algorithms on host.
+
+#include <sycl/sycl.hpp>
+
+#include <cstdint>
+#include <type_traits>
+
+template <size_t Size>
+using get_uint_type_of_size = typename std::conditional_t<
+    Size == 1, uint8_t,
+    std::conditional_t<
+        Size == 2, uint16_t,
+        std::conditional_t<Size == 4, uint32_t,
+                           std::conditional_t<Size == 8, uint64_t, void>>>>;
+
+using bfloat16 = sycl::ext::oneapi::experimental::bfloat16;
+using Bfloat16StorageT = get_uint_type_of_size<sizeof(bfloat16)>;
+
+bool test(float Val, Bfloat16StorageT Bits) {
+  std::cout << "Value: " << Val << " Bits: " << std::hex << "0x" << Bits
+            << std::dec << "...\n";
+  bool Passed = true;
+  {
+    std::cout << "  float -> bfloat16 conversion ...";
+    Bfloat16StorageT RawVal = sycl::bit_cast<Bfloat16StorageT>(bfloat16(Val));
+    bool Res = (RawVal == Bits);
+    Passed &= Res;
+
+    if (Res) {
+      std::cout << "passed\n";
+    } else {
+      std::cout << "failed. " << std::hex << "0x" << RawVal << " != "
+                << "0x" << Bits << "(gold)\n"
+                << std::dec;
+    }
+  }
+  {
+    std::cout << "  bfloat16 -> float conversion ...";
+    float NewVal = static_cast<float>(sycl::bit_cast<bfloat16>(Bits));
+    bool Res = (NewVal == Val);
+    Passed &= Res;
+
+    if (Res) {
+      std::cout << "passed\n";
+    } else {
+      std::cout << "failed. " << Val << "(Gold) != " << NewVal << "\n";
+    }
+  }
+  return Passed;
+}
+
+int main() {
+  bool passed = true;
+  passed &= test(3.140625f, 0x4049);
+  std::cout << (passed ? "Test Passed\n" : "Test FAILED\n");
+  return (passed ? 0 : 1);
+}