Using noexcept multilib with -fno-exceptions can lead to significant
space savings when statically linking libc++abi because we don't need
all the unwinding and demangling code.
When compiling with ASan, we already get a lot of overhead from the
instrumentation itself, when statically linking libc++abi, that overhead
is even larger.
Having the noexcept variant for ASan can help significantly, we've seen
more than 50% size reduction in our system image, which offsets the cost
of having to build another multilib.
Differential Revision: https://reviews.llvm.org/D64140
llvm-svn: 365994
This is a follow up to r361432 and r361504 which addresses issues
introduced by those changes. Specifically, it avoids duplicating
file and runtime paths in case when the effective triple is the
same as the cannonical one. Furthermore, it fixes the broken multilib
setup in the Fuchsia driver and deduplicates some of the code.
Differential Revision: https://reviews.llvm.org/D62442
llvm-svn: 361709
Petr Hosek