First patch to fix a BIND(C) ABI issue
(https://github.com/llvm/llvm-project/issues/102113). I need to keep
track of BIND(C) in more locations (fir.dispatch and func.func
operations), and I need to fix a few passes that are dropping the
attribute on the floor. Since I expect more procedure attributes that
cannot be reflected in mlir::FunctionType will be needed for ABI,
optimizations, or debug info, this NFC patch adds a new enum attribute
to keep track of procedure attributes in the IR.
This patch is not updating lowering to lower more attributes, this will
be done in a separate patch to keep the test changes low here.
Adding the attribute on fir.dispatch and func.func will also be done in
separate patches.
Constants actual arguments in function/subroutine calls are currently
lowered as allocas + store. This can sometimes inhibit LTO and the
constant will not be propagated to the called function. Particularly in
cases where the function/subroutine call happens inside a condition.
This patch changes the lowering of these constant actual arguments to a
global constant + fir.address_of_op. This lowering makes it easier for
LTO to propagate the constant.
The optimization must be enabled explicitly to run. Use -mmlir
--enable-constant-argument-globalisation to enable.
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Co-authored-by: Dmitriy Smirnov <dmitriy.smirnov@arm.com>
