* Got side-tracked hunting down a vague-linkage RTTI issue due to not anchoring key methods in PassOptions.h to a module.
* Took the path of least resistance and just added the option to build LLVM with RTTI. I know how to fix this but would like to do some broader upstream fixes versus just hunting/pecking/working around in this project.
The secret here is LLVM_ENABLE_WARNINGS=ON.
I also fixed a couple warnings, which gets us to be warning-clean.
I noticed also that npcomp-run-mlir/basic.mlir seems to be failing.
Maybe something since the latest integrate. My next commit (introduce
npcomp mini runtime) will largely rewrite it though, so it'll get fixed
then.
This script (make sure to `source` it!) defines a number of handy
aliases which make compiler development more convenient.
Please feel free to add anything you find useful here.
The code isn't super clean, but is a useful incremental step
establishing most of the boilerplate for future enhancements.
We can't print or return tensors yet so correctness TBD, but I've
stepped into the running code in the debugger so I know it definitely is
running.
This is the first step to building out an npcomp mini-runtime. The
mini-runtime doesn't have to be fancy or complex, but it should at least
be layered nicely (which this code and the current compiler interaction
with the "runtime" code is not). Now that we have boilerplate for e2e
execution in some form, we can build that out.
With this commit, we finish conversion to LLVM dialect, and should be
ready for subsequent commits to convert to an LLVM module and let LLVM
codegen to native machine code.
This required a custom "lower to LLVM" pass to support lowering
tcp.abort_if to a runtime call. In the future, this pass will grow to do
type conversions for our own runtime types as we add those.
This more clearly captures its semantics as a structural "observer" of
code that we currently mark as NoSideEffect but eventually lowers to
eager error handling code.
Also, update LowerRankedShapes to erase it, now that the layering here
is clear. That pass reifies the eager error handling code, so the need
for the dummy op to keep things alive isn't needed.
With this change, we are now ready to start lowering to LLVM!
This is the current print-ir-after-all from e2e-lowering-pipeline:
https://reviews.llvm.org/P8221
Specifically, we use unranked memrefs which get passed as a fixed-size
set of arguments/returns. One big caveat about this is that returning
results isn't going to work. See TODO in LowerTensorLoadOp.
This is far from enough runtime-wise, but it starts to demarcate a
plausible layering. Notice for example how this removes the
runtime-dependence from LowerRankedShapes.
Eventually, we want to have an `npcomp_rt` or `npcomp_hal` dialect with
its own set of runtime types that will supercede this.
See comments in LowerTensorLoadOp for more direction about where this is
going to evolve.
The idea was half-baked and after some deep thought felt like a solution
looking for a problem. What we had here (and is removed in this patch)
just wasn't pulling its weight.
I cannot think of anything we would want to do with tcp.island as it is
removed here beyond just sinking and merging them within a basic block,
such that the witness argument is kind of pointless (only matters for
hoisting).
TCP compute ops like tcp.add and tcp.broadcast_to have the strong
invariant of "pure or undefined behavior", which means they are always
safe to sink. The island concept as removed here conferred no benefit.
Also, I'll note that "islands" are a trick you can only play once in a
system (unless they strictly nest). I have some early-stage thoughs on
having an island concept that helps with modeling tensor shapes
robustly which seems promising (the island would serve a similar role as
tie_shape).
- Make rank1.mlir be the new "basic.mlir", as it is really the simplest
case.
- Move basic.mlir to mixed-ranks.mlir
- Delete starting-from-linalg.mlir, it wasn't really useful anymore.
This uses an approach inspired by what is done in IREE. See comments on
LowerRankedShapes.cpp for how it works.
The basic gist is that we have an op that creates a !shape.shape from a
set of SSA values representing the extents, and then iteratively replace
any op producing a !shape.shape with instances of that op.
This also adds a small pass to clean up the `dim` ops that linalg
introduces. For now, it only has a trivial pattern that looks for a
`tcp.alloc_memref(%shape)` op to get the shape as we currently have an
invariant that all memrefs are the result of such ops.
But eventually this will need to look through view ops and any other
shape-ish stuff that linalg introduces as it lowers to loops, along with
any slicing ops introduced by buffer allocation.
There's a lot of details to flesh out here, but the basic approach seems
promising (see comments in createE2ELoweringPipeline).
This approach will be put to the test when we try to do our first
fusions since that tickles some of the nasty phase ordering issues
involved here.
But we're not there yet.
This makes sure we stay resonably canonically using the shape machinery.
(In fact, DimOp should probably be in the shape dialect since it hides a
`shape.shape_of` call)
We should look into having a `ninja check-npcomp` that runs everything
with lit so that we get decent test multithreading.
We can look to how LLVM does its gtest tests ("unittests") for
inspiration.
Stella Laurenzo
Sean Silva