Support a new assembler directive, .import_global, to declare imported
global variables (i.e. those with external linkage and no
initializer). The linker turns these into wasm imports.
Patch by Jacob Gravelle
Differential Revision: https://reviews.llvm.org/D26875
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288296 91177308-0d34-0410-b5e6-96231b3b80d8
This changes locals from being declared by the emitLocal hook in
WebAssemblyTargetStreamer, rather than with an instruction. After exploring
the infastructure in LLVM more, this seems to make more sense since
declaring locals doesn't use an encoded opcode.
This also adds more 0xd opcodes, type encodings, and miscellaneous
binary encoding bits.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285040 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: This patch implements CFI for WebAssembly. It modifies the
LowerTypeTest pass to pre-assign table indexes to functions that are
called indirectly, and lowers type checks to test against the
appropriate table indexes. It also modifies the WebAssembly backend to
support a special ".indidx" assembly directive that propagates the table
index assignments out to the linker.
Patch by Dominic Chen
Differential Revision: https://reviews.llvm.org/D21768
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277398 91177308-0d34-0410-b5e6-96231b3b80d8
Under emscripten, C code can take the address of a function implemented
in Javascript (which is exposed via an import in wasm). Because imports
do not have linear memory address in wasm, we need to generate a thunk
to be the target of the indirect call; it call the import directly.
To make this possible, LLVM needs to emit the type signatures for these
functions, because they may not be called directly or referred to other
than where the address is taken.
This uses s new .s directive (.functype) which specifies the signature.
Differential Revision: http://reviews.llvm.org/D20891
Re-apply r271599 but instead of bailing with an error when a declared
function has multiple returns, replace it with a pointer argument. Also
add the test case I forgot to 'git add' last time around.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271703 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts r271599, it broke the integration tests.
More places than I expected had nontrival return types in imports, or
else the check was wrong.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271606 91177308-0d34-0410-b5e6-96231b3b80d8
Under emscripten, C code can take the address of a function implemented
in Javascript (which is exposed via an import in wasm). Because imports
do not have linear memory address in wasm, we need to generate a thunk
to be the target of the indirect call; it call the import directly.
To make this possible, LLVM needs to emit the type signatures for these
functions, because they may not be called directly or referred to other
than where the address is taken.
This uses s new .s directive (.functype) which specifies the signature.
Differential Revision: http://reviews.llvm.org/D20891
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271599 91177308-0d34-0410-b5e6-96231b3b80d8
Move the register stackification and coloring passes to run very late, after
PEI, tail duplication, and most other passes. This means that all code emitted
and expanded by those passes is now exposed to these passes. This also
eliminates the need for prologue/epilogue code to be manually stackified,
which significantly simplifies the code.
This does require running LiveIntervals a second time. It's useful to think
of these late passes not as late optimization passes, but as a domain-specific
compression algorithm based on knowledge of liveness information. It's used to
compress the code after all conventional optimizations are complete, which is
why it uses LiveIntervals at a phase when actual optimization passes don't
typically need it.
Differential Revision: http://reviews.llvm.org/D20075
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269012 91177308-0d34-0410-b5e6-96231b3b80d8
Refactor .param, .result, .local, and .endfunc, as directives, using the
proper MCTargetStreamer mechanism, rather than fake instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257511 91177308-0d34-0410-b5e6-96231b3b80d8
This patch changes the way labels are referenced. Instead of referencing the
basic-block label name (eg. .LBB0_0), instructions now just have an immediate
which indicates the depth in the control-flow stack to find a label to jump to.
This makes them much closer to what we expect to have in the binary encoding,
and avoids the problem of basic-block label names not being explicit in the
binary encoding.
Also, it terminates blocks and loops with end_block and end_loop instructions,
rather than basic-block label names, for similar reasons.
This will also fix problems where two constructs appear to have the same label,
because we no longer explicitly use labels, so consumers that need labels will
presumably create their own labels, and presumably they won't reuse labels
when they do.
This patch does make the code a little more awkward to read; as a partial
mitigation, this patch also introduces comments showing where the labels are,
and comments on each branch showing where it's branching to.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257505 91177308-0d34-0410-b5e6-96231b3b80d8
Currently WebAssembly has two kinds of relocations; data addresses and
function addresses. This adds ELF relocations for them, as well as an
MC symbol kind to indicate which type of relocation is needed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257416 91177308-0d34-0410-b5e6-96231b3b80d8
Derek Schuff
Dan Gohman
Mehdi Amini