[SYCL] Support rotating by over-sized shift widths.

Signed-off-by: Joshua Cranmer <joshua.cranmer@intel.com>

Author: jcranmer-intel

sycl/source/detail/builtins_integer.cpp

@@ -154,7 +154,12 @@ template <typename T> inline T __u_long_mad_sat(T a, T b, T c) {
 
 template <typename T> inline T __rotate(T x, T n) {
   using UT = typename std::make_unsigned<T>::type;
-  return (x << n) | (UT(x) >> ((sizeof(x) * 8) - n));
+  // Shrink the shift width so that it's in the range [0, num_bits(T)). Cast
+  // everything to unsigned to avoid type conversion issues.
+  constexpr UT size = sizeof(x) * 8;
+  UT xu = UT(x);
+  UT nu = UT(n) & (size - 1);
+  return (xu << nu) | (xu >> (size - nu));
 }
 
 template <typename T> inline T __u_sub_sat(T x, T y) {

sycl/test/built-ins/scalar_integer.cpp

@@ -319,6 +319,22 @@ int main() {
     assert(r == 0x00000111);
   }
 
+  // rotate (with large rotate size)
+  {
+    s::cl_char r{ 0 };
+    {
+      s::buffer<s::cl_char, 1> BufR(&r, s::range<1>(1));
+      s::queue myQueue;
+      myQueue.submit([&](s::handler &cgh) {
+        auto AccR = BufR.get_access<s::access::mode::write>(cgh);
+        cgh.single_task<class rotateSI1SI2>([=]() {
+          AccR[0] = s::rotate(static_cast<s::cl_char>((unsigned char)0xe0),
+              s::cl_char{ 50 });
+        });
+      });
+    }
+    assert((unsigned char)r == 0x83);
+  }
   // sub_sat
   {
     s::cl_int r{ 0 };