SYCL compilations initiated by the driver will spawn off one or more
frontend compilation jobs (one for device and one for host). This patch
reworks the driver options to make upstreaming this from the downstream
SYCL fork easier.
This patch introduces a language option to identify host executions
(SYCLIsHost) and a -cc1 frontend option to enable this mode. -fsycl and
-fno-sycl become driver-only options that are rejected when passed to
-cc1. This is because the frontend and beyond should be looking at
whether the user is doing a device or host compilation specifically.
Because the frontend should only ever be in one mode or the other,
-fsycl-is-device and -fsycl-is-host are mutually exclusive options.
SYCL device compiler (similar to other SPMD compilers) assumes that
functions are convergent by default to avoid invalid transformations.
This attribute can be removed if compiler can prove that function does
not have convergent operations.
Reviewed By: Naghasan
Differential Revision: https://reviews.llvm.org/D87282
The CUDA backend (and other downstreams) have trouble with the tilde and
arrow delimiter, so replace these with 'm' (for macro) and '_'. Since
these are in the normal lambda ID location, the format of these should
not conflict with anything else.
In order to support non-user-named kernels, SYCL needs some way in the
integration headers to name the kernel object themselves. Initially, the
design considered just RTTI naming of the lambdas, this results in a
quite unstable situation in light of some device/host macros.
Additionally, this ends up needing to use RTTI, which is a burden on the
implementation and typically unsupported.
Instead, we've introduced a builtin, __builtin_unique_stable_name, which
takes a type or expression, and results in a constexpr constant
character array that uniquely represents the type (or type of the
expression) being passed to it.
The implementation accomplishes that simply by using a slightly modified
version of the Itanium Mangling. The one exception is when mangling
lambdas, instead of appending the index of the lambda in the function,
it appends the macro-expansion back-trace of the lambda itself in the
form LINE->COL[~LINE->COL...].
Differential Revision: https://reviews.llvm.org/D76620
Aaron Ballman