Adds flang/include/flang/Common/log2-visit.h, which defines
a Fortran::common::visit() template function that is a drop-in
replacement for std::visit(). Modifies most use sites in
the front-end and runtime to use common::visit().
The C++ standard mandates that std::visit() have O(1) execution
time, which forces implementations to build dispatch tables.
This new common::visit() is O(log2 N) in the number of alternatives
in a variant<>, but that N tends to be small and so this change
produces a fairly significant improvement in compiler build
memory requirements, a 5-10% improvement in compiler build time,
and a small improvement in compiler execution time.
Building with -DFLANG_USE_STD_VISIT causes common::visit()
to be an alias for std::visit().
Calls to common::visit() with multiple variant arguments
are referred to std::visit(), pending further work.
This change is enabled only for GCC builds with GCC >= 9;
an earlier attempt (D122441) ran into bugs in some versions of
clang and was reverted rather than simply disabled; and it is
not well tested with MSVC. In non-GCC and older GCC builds,
common::visit() is simply an alias for std::visit().
Adds flang/include/flang/Common/visit.h, which defines
a Fortran::common::visit() template function that is a drop-in
replacement for std::visit(). Modifies most use sites in
the front-end and runtime to use common::visit().
The C++ standard mandates that std::visit() have O(1) execution
time, which forces implementations to build dispatch tables.
This new common::visit() is O(log2 N) in the number of alternatives
in a variant<>, but that N tends to be small and so this change
produces a fairly significant improvement in compiler build
memory requirements, a 5-10% improvement in compiler build time,
and a small improvement in compiler execution time.
Building with -DFLANG_USE_STD_VISIT causes common::visit()
to be an alias for std::visit().
Calls to common::visit() with multiple variant arguments
are referred to std::visit(), pending further work.
Differential Revision: https://reviews.llvm.org/D122441
An LLVM Flang build bot for Windows recently failed with a
bunch of warning messages. None were from recent changes to
the Fortran compiler; I suspect that a newer (or maybe older)
version of MSVC was being used, or perhaps a different set of
compiler options were temporarily applied to the build, since
the buildbot status went back to green shortly thereafter.
Most of the warnings looked bogus to me, but some are legitimate
concerns and we might as well clean them up. This patch does so.
Differential Revision: https://reviews.llvm.org/D111677
When the ProcRef is Symbol is a SubprogramDetails, the interface is
the SubprogramDetails. Do not return nullptr.
Differential Revision: https://reviews.llvm.org/D110853
Internal subprograms have explicit interfaces. If an internal subprogram has
an alternate return, we check its explicit interface. But we were not
putting the label values of alternate returns into the actual argument.
I fixed this by changing the definition of actual arguments to be able
to contain a common::Label and putting the label for an alternate return
into the actual argument.
I also verified that we were already doing all of the semantic checking
required for alternate returns and removed a "TODO" for this.
I also added the test altreturn06.f90.
Differential Revision: https://reviews.llvm.org/D94017
Fix fronted shared library builds by eliminating dependences of
the parser on other component libraries, moving some code around that
wasn't in the right library, and making some dependences
explicit in the CMakeLists.txt files. The lowering library
does not yet build as a shared library due to some undefined
names.
Reviewed By: tskeith
Differential Revision: https://reviews.llvm.org/D83515
Rolls up small changes across the frontend to prepare for the large
forthcoming patch (part 4/4) that completes DATA statement processing
via conversion to initializers.
Reviewed By: PeteSteinfeld
Differential Revision: https://reviews.llvm.org/D82137
Peter Klausler