make prefetch intrinsics safe

Author: folkertdev

tests/pass/prefetch.rs

@@ -1,23 +1,23 @@
 #![feature(core_intrinsics)]
 
+// Test that these intrinsics work. Their behavior should be a no-op.
+
 fn main() {
     static X: [u8; 8] = [0; 8];
 
-    unsafe {
-        ::std::intrinsics::prefetch_read_data(::std::ptr::null::<u8>(), 1);
-        ::std::intrinsics::prefetch_read_data(::std::ptr::dangling::<u8>(), 2);
-        ::std::intrinsics::prefetch_read_data(X.as_ptr(), 3);
+    ::std::intrinsics::prefetch_read_data::<_, 1>(::std::ptr::null::<u8>());
+    ::std::intrinsics::prefetch_read_data::<_, 2>(::std::ptr::dangling::<u8>());
+    ::std::intrinsics::prefetch_read_data::<_, 3>(X.as_ptr());
 
-        ::std::intrinsics::prefetch_write_data(::std::ptr::null::<u8>(), 1);
-        ::std::intrinsics::prefetch_write_data(::std::ptr::dangling::<u8>(), 2);
-        ::std::intrinsics::prefetch_write_data(X.as_ptr(), 3);
+    ::std::intrinsics::prefetch_write_data::<_, 1>(::std::ptr::null::<u8>());
+    ::std::intrinsics::prefetch_write_data::<_, 2>(::std::ptr::dangling::<u8>());
+    ::std::intrinsics::prefetch_write_data::<_, 3>(X.as_ptr());
 
-        ::std::intrinsics::prefetch_read_instruction(::std::ptr::null::<u8>(), 1);
-        ::std::intrinsics::prefetch_read_instruction(::std::ptr::dangling::<u8>(), 2);
-        ::std::intrinsics::prefetch_read_instruction(X.as_ptr(), 3);
+    ::std::intrinsics::prefetch_read_instruction::<_, 1>(::std::ptr::null::<u8>());
+    ::std::intrinsics::prefetch_read_instruction::<_, 2>(::std::ptr::dangling::<u8>());
+    ::std::intrinsics::prefetch_read_instruction::<_, 3>(X.as_ptr());
 
-        ::std::intrinsics::prefetch_write_instruction(::std::ptr::null::<u8>(), 1);
-        ::std::intrinsics::prefetch_write_instruction(::std::ptr::dangling::<u8>(), 2);
-        ::std::intrinsics::prefetch_write_instruction(X.as_ptr(), 3);
-    }
+    ::std::intrinsics::prefetch_write_instruction::<_, 1>(::std::ptr::null::<u8>());
+    ::std::intrinsics::prefetch_write_instruction::<_, 2>(::std::ptr::dangling::<u8>());
+    ::std::intrinsics::prefetch_write_instruction::<_, 3>(X.as_ptr());
 }