For IR generated by a compiler, this is really simple: you just take the
datalayout from the beginning of the file, and apply it to all the IR
later in the file. For optimization testcases that don't care about the
datalayout, this is also really simple: we just use the default
datalayout.
The complexity here comes from the fact that some LLVM tools allow
overriding the datalayout: some tools have an explicit flag for this,
some tools will infer a datalayout based on the code generation target.
Supporting this properly required plumbing through a bunch of new
machinery: we want to allow overriding the datalayout after the
datalayout is parsed from the file, but before we use any information
from it. Therefore, IR/bitcode parsing now has a callback to allow tools
to compute the datalayout at the appropriate time.
Not sure if I covered all the LLVM tools that want to use the callback.
(clang? lli? Misc IR manipulation tools like llvm-link?). But this is at
least enough for all the LLVM regression tests, and IR without a
datalayout is not something frontends should generate.
This change had some sort of weird effects for certain CodeGen
regression tests: if the datalayout is overridden with a datalayout with
a different program or stack address space, we now parse IR based on the
overridden datalayout, instead of the one written in the file (or the
default one, if none is specified). This broke a few AVR tests, and one
AMDGPU test.
Outside the CodeGen tests I mentioned, the test changes are all just
fixing CHECK lines and moving around datalayout lines in weird places.
Differential Revision: https://reviews.llvm.org/D78403
Sometimes users do not specify data layout in LLVM assembly and let llc set the
data layout by target triple after loading the LLVM assembly.
Currently the parser checks alloca address space no matter whether the LLVM
assembly contains data layout definition, which causes false alarm since the
default data layout does not contain the correct alloca address space.
The parser also calls verifier to check debug info and updating invalid debug
info. Currently there is no way to let the verifier to check debug info only.
If the verifier finds non-debug-info issues the parser will fail.
For llc, the fix is to remove the check of alloca addr space in the parser and
disable updating debug info, and defer the updating of debug info and
verification to be after setting data layout of the IR by target.
For other llvm tools, since they do not override data layout by target but
instead can override data layout by a command line option, an argument for
overriding data layout is added to the parser. In cases where data layout
overriding is necessary for the parser, the data layout can be provided by
command line.
Differential Revision: https://reviews.llvm.org/D41832
llvm-svn: 323826
Eli Friedman