When building a fatbinary, the driver invokes the compiler multiple
times with different "--target". (For example, with "-x cuda
--cuda-gpu-arch=sm_70" flags, clang will be invoded twice, once with
--target=x86_64_...., once with --target=sm_70) If we use
-fsplit-machine-functions or -fno-split-machine-functions for such
invocation, the driver reports an error.
This CL changes the behavior so:
- "-fsplit-machine-functions" is now passed to all targets, for non-X86
targets, the flag is a NOOP and causes a warning.
- "-fno-split-machine-functions" now negates -fsplit-machine-functions (if
-fno-split-machine-functions appears after any -fsplit-machine-functions)
for any target triple, previously, it causes an error.
- "-fsplit-machine-functions -Xarch_device -fno-split-machine-functions"
enables MFS on host but disables MFS for GPUS without warnings/errors.
- "-Xarch_host -fsplit-machine-functions" enables MFS on host but disables
MFS for GPUS without warnings/errors.
Reviewed by: xur, dhoekwater
Differential Revision: https://reviews.llvm.org/D157750
317a0fe5bd