sycl::ctz seems to be missing from the implementation

[AlexeySachkov]

Discussed in #4450

^{Originally posted by zjin-lcf September 1, 2021}
With the latest build, the compiler shows the message:

error: no member named 'ctz' in namespace 'sycl'; did you mean 'clz'?

Thanks

Note: the built-in is documented by SYCL 2020 spec in section 4.17.6. Integer functions

@yuriykoch, @bader, seems like a gap in SYCL-CTS testing if we haven't found this ourselves

[bader]

FYI: ctz has been introduced with SYCL 2020 version and CTS for this version is still under development.

[AlexeySachkov]

@zjin-lcf, I've just realized that we have already implemented ctz, but only as sycl::ext::intel::ctz - you can try using it for now as a workaround:

llvm/sycl/include/CL/sycl/builtins.hpp

Lines 727 to 736 in 8d030ec

	namespace ext {
	namespace intel {
	// geninteger ctz (geninteger x)
	template <typename T>
	sycl::detail::enable_if_t<sycl::detail::is_geninteger<T>::value, T>
	ctz(T x) __NOEXC {
	return __sycl_std::__invoke_ctz<T>(x);
	}
	} // namespace intel
	} // namespace ext

[zjin-lcf]

Thanks!

[zjin-lcf]

I find that it is sycl::intel::ctz in the oneAPI toolkit 2021.3

[vladimirlaz]

Tthe fix for the issue is available in #5223 and #5333.
Close the issue.