* Cranelift: Use a single, shared vector allocation for all `ABIArg`s
Instead of two `SmallVec`s per `SigData`.
* Remove `Deref` and `DerefMut` impls for `ArgsAccumulator`
Adds Bswap to the Cranelift IR. Implements the Bswap instruction
in the x64 and aarch64 codegen backends. Cranelift users can now:
```
builder.ins().bswap(value)
```
to get a native byteswap instruction.
* x64: implements the 32- and 64-bit bswap instruction, following
the pattern set by similar unary instrutions (Neg and Not) - it
only operates on a dst register, but is parameterized with both
a src and dst which are expected to be the same register.
As x64 bswap instruction is only for 32- or 64-bit registers,
the 16-bit swap is implemented as a rotate left by 8.
Updated x64 RexFlags type to support emitting for single-operand
instructions like bswap
* aarch64: Bswap gets emitted as aarch64 rev16, rev32,
or rev64 instruction as appropriate.
* s390x: Bswap was already supported in backend, just had to add
a bit of plumbing
* For completeness, added bswap to the interpreter as well.
* added filetests and runtests for each ISA
* added bswap to fuzzgen, thanks to afonso360 for the code there
* 128-bit swaps are not yet implemented, that can be done later
* aarch64: Fix incorrect masking for small types on bmask
`bmask` was accidentally relying on the uppermost bits of the register
for small types.
This was found by fuzzgen, when it generated a shift left followed by
a bmask, the shift left shifted the bits out of the range of the input
type (i8), however these are not automatically cleared since they
remained inside the 32 bits of the register.
That caused issues when the bmask tried to compare the whole register
instead of just the bottom bits. The solution here is to mask the upper
bits for small types.
* aarch64: Emit 32bit cmp on bmask
This fixes an issue where bmask was accidentally comparing the
upper bits of the register by always using a 64bit cmp.
* riscv: Mask high bits in bmask
* riscv: Add compile tests for br{z,nz}
* riscv: Use shifts to mask 32bit values
This produces less code than the AND since that version needs to
load an immediate constant from memory.
* cranelift: Update test input to hexadecimal values
This makes it a bit more clear what is being tested.
* riscv: Use addiw for masking 32 bit values
Co-authored-by: Trevor Elliott <telliott@fastly.com>
* aarch64: Update bmask rule priority
Co-authored-by: Trevor Elliott <telliott@fastly.com>
Add a new instruction uadd_overflow_trap, which is a fused version of iadd_ifcout and trapif. Adding this instruction removes a dependency on the iflags type, and would allow us to move closer to removing it entirely.
The instruction is defined for the i32 and i64 types only, and is currently only used in the legalization of heap_addr.
In particular, this was found to happen in #5099 because a `Result`
projection node was not deduplicating across two separate `isplit`s that
created it. (This is a separate issue we should also fix; `needs_dedup`
is I think overly conservative because `Result` can project out a single
value from a pure or impure node, but the projection itself should be
treated like any other pure operator.)
In any case, if we have a value `v0` and two separate `Result { value:
v0, result: N, ty }` nodes, each of these will fill in the type `ty` for
the `N`th output of `v0`, and the second will idempotently overwrite the
first; we should loosen the assert so that it allows this case.
Fixes#5099. Fixes#5100.
* Cranelift: pass iterators to `ABIMachineSpec::compute_arg_locs`
Instead of slices. This gives us more flexibility to pass custom sequences
without needing to allocate a `Vec` to hold them and pass in as a slice.
* Cranelift: Avoid cloning `ir::Signature`s in `SigData::from_func_sig`
This avoids two heap allocations per signature that are unnecessary 99% of the
time.
* fix typo
* Simplify condition in `missing_struct_return`
As discussed in the 2022/10/19 meeting, this PR removes many of the branch and select instructions that used iflags, in favor if using brz/brnz and select in their place. Additionally, it reworks selectif_spectre_guard to take an i8 input instead of an iflags input.
For reference, the removed instructions are: br_icmp, brif, brff, trueif, trueff, and selectif.
* cranelift: Remove iconst.i128
* bugpoint: Report Changed when only one instruction is mutated
* cranelift: Fix egraph bxor rule
* cranelift: Remove some simple_preopt opts for i128
Eliminate a few remaining instances of non-SSA code.
Remove infrastructure previously used for non-SSA code emission.
Related cleanup around flags handling.
This can help rustc/llvm avoid bounds checks, but more importantly I will have
future changes here that remove indexing of params, and instead hand them out as
an iterator.
The `SigData::from_func_sig` constructor will already ensure that the struct
return pointer is returned, so this is a purely unnecessary call.
Note that this is not a performance speed up, since
`ensure_struct_return_ptr_is_returned` doesn't do any significant work if the
signature is already legalized.
This fixes#5086 by addressing two separate issues:
- The `ValueDataPacked::set_type()` helper had an embarrassing bitfield-manipulation bug that would mangle the rest of a `ValueDef` when setting its type. This is not normally used, only when the egraph elaboration fills in types after-the-fact on a multi-value node.
- The lowering rules for `isplit` on aarch64 and s390x were dispatching on the first output type, rather than the input type. When only the second output is used (as in the example in #5086), the first output type actually remains `INVALID` (and this is fine because it's never used).
Remove uses of reg_mod from the s390x backend. This required moving away from using r0/r1 as the result registers from a few different pseudo instructions, standardizing instead on r2/r3. That change was necessary as regalloc2 will not correctly allocate registers that aren't listed in the allocatable set, which r0/r1 are not.
Co-authored-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Co-authored-by: Chris Fallin <chris@cfallin.org>
* fuzzgen: Test compiler flags
* cranelift: Generate `all()` function for all enum flags
This allows a user to iterate all flags that exist.
* fuzzgen: Minimize regalloc_checker compiles
* fuzzgen: Limit the amount of test case inputs
* fuzzgen: Add egraphs flag
It's finally here! 🥳
* cranelift: Add fuzzing comment to settings
* fuzzgen: Add riscv64
* fuzzgen: Unconditionally enable some flags
* egraphs: a few miscellaneous compile-time optimizations.
These optimizations together are worth about a 2% compile-time
reduction, as measured on one core with spidermonkey.wasm as an input,
using `hyperfine` on `wasmtime compile`.
The changes included are:
- Some better pre-allocation (blockparams and side-effects concatenated
list vecs);
- Avoiding the indirection of storing list-of-types for every Pure and
Inst node, when almost all nodes produce only a single result;
instead, store arity and single type if it exists, and allow result
projection nodes to fill in types otherwise;
- Pack the `MemoryState` enum into one `u32` (this together with the
above removal of the type slice allows `Node` to
shrink from 48 bytes to 32 bytes);
- always-inline an accessor (`entry` on `CtxHash`) that wasn't
(`always(inline)` appears to be load-bearing, rather than just
`inline`);
- Split the update-analysis path into two hotpaths, one for the union
case and one for the new-node case (and the former can avoid
recomputing for the contained node when replacing a node with
node-and-child eclass entry).
* Review feedback.
* Fix test build.
* Fix to lowering when unused output with invalid type is present.
Remove the boolean types from cranelift, and the associated instructions breduce, bextend, bconst, and bint. Standardize on using 1/0 for the return value from instructions that produce scalar boolean results, and -1/0 for boolean vector elements.
Fixes#3205
Co-authored-by: Afonso Bordado <afonso360@users.noreply.github.com>
Co-authored-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Co-authored-by: Chris Fallin <chris@cfallin.org>
This is a simple error in the const-prop rules: uextend was not
masking iconst's u64 immediate when extending from i32 to
i64. Arguably an iconst.i32 should not have nonzero bits in the upper
32 of its immediate, but that's a separate design question. For now,
if our invariant is that the upper bits are ignored, then it is
required to mask the bits when const-evaling a `uextend`.
Fixes#5047.
* egraph-based midend: draw the rest of the owl.
* Rename `egg` submodule of cranelift-codegen to `egraph`.
* Apply some feedback from @jsharp during code walkthrough.
* Remove recursion from find_best_node by doing a single pass.
Rather than recursively computing the lowest-cost node for a given
eclass and memoizing the answer at each eclass node, we can do a single
forward pass; because every eclass node refers only to earlier nodes,
this is sufficient. The behavior may slightly differ from the earlier
behavior because we cannot short-circuit costs to zero once a node is
elaborated; but in practice this should not matter.
* Make elaboration non-recursive.
Use an explicit stack instead (with `ElabStackEntry` entries,
alongside a result stack).
* Make elaboration traversal of the domtree non-recursive/stack-safe.
* Work analysis logic in Cranelift-side egraph glue into a general analysis framework in cranelift-egraph.
* Apply static recursion limit to rule application.
* Fix aarch64 wrt dynamic-vector support -- broken rebase.
* Topo-sort cranelift-egraph before cranelift-codegen in publish script, like the comment instructs me to!
* Fix multi-result call testcase.
* Include `cranelift-egraph` in `PUBLISHED_CRATES`.
* Fix atomic_rmw: not really a load.
* Remove now-unnecessary PartialOrd/Ord derivations.
* Address some code-review comments.
* Review feedback.
* Review feedback.
* No overlap in mid-end rules, because we are defining a multi-constructor.
* rustfmt
* Review feedback.
* Review feedback.
* Review feedback.
* Review feedback.
* Remove redundant `mut`.
* Add comment noting what rules can do.
* Review feedback.
* Clarify comment wording.
* Update `has_memory_fence_semantics`.
* Apply @jameysharp's improved loop-level computation.
Co-authored-by: Jamey Sharp <jamey@minilop.net>
* Fix suggestion commit.
* Fix off-by-one in new loop-nest analysis.
* Review feedback.
* Review feedback.
* Review feedback.
* Use `Default`, not `std::default::Default`, as per @fitzgen
Co-authored-by: Nick Fitzgerald <fitzgen@gmail.com>
* Apply @fitzgen's comment elaboration to a doc-comment.
Co-authored-by: Nick Fitzgerald <fitzgen@gmail.com>
* Add stat for hitting the rewrite-depth limit.
* Some code motion in split prelude to make the diff a little clearer wrt `main`.
* Take @jameysharp's suggested `try_into()` usage for blockparam indices.
Co-authored-by: Jamey Sharp <jamey@minilop.net>
* Take @jameysharp's suggestion to avoid double-match on load op.
Co-authored-by: Jamey Sharp <jamey@minilop.net>
* Fix suggestion (add import).
* Review feedback.
* Fix stack_load handling.
* Remove redundant can_store case.
* Take @jameysharp's suggested improvement to FuncEGraph::build() logic
Co-authored-by: Jamey Sharp <jamey@minilop.net>
* Tweaks to FuncEGraph::build() on top of suggestion.
* Take @jameysharp's suggested clarified condition
Co-authored-by: Jamey Sharp <jamey@minilop.net>
* Clean up after suggestion (unused variable).
* Fix loop analysis.
* loop level asserts
* Revert constant-space loop analysis -- edge cases were incorrect, so let's go with the simple thing for now.
* Take @jameysharp's suggestion re: result_tys
Co-authored-by: Jamey Sharp <jamey@minilop.net>
* Fix up after suggestion
* Take @jameysharp's suggestion to use fold rather than reduce
Co-authored-by: Jamey Sharp <jamey@minilop.net>
* Fixup after suggestion
* Take @jameysharp's suggestion to remove elaborate_eclass_use's return value.
* Clarifying comment in terminator insts.
Co-authored-by: Jamey Sharp <jamey@minilop.net>
Co-authored-by: Nick Fitzgerald <fitzgen@gmail.com>
* Cranelift: Make `Opcode` represented as a `u8` instead of `u16`
* Cranelift: Remove unused conversion impls for `Opcode`
These are vestigial, left over from Peepmatic.
* Fix StructReturn handling: properly mark the clobber, and offset actual rets.
The legalization of `StructReturn` was causing issues in the new
call-handling code: the `StructReturn` ret was included in the `SigData` as
if it were an actual CLIF-level return value, but it is not.
Prior to using regalloc constraints for return values, we
unconditionally included rax (or the architecture's usual return
register) as a def, so it would be properly handled as "clobbered" by
the regalloc. With the new scheme, we include defs on the call only for
CLIF-level outputs. Callees with `StructReturn` args were thus not known
to clobber the return-value register, and values might be corrupted.
This PR updates the code to include a `StructReturn` ret as a clobber
rather than a returned value in the relevant spots. I observed it
causing saves/restores of rax in some CLIF that @bjorn3 provided me, but
I was having difficulty minimizing this into a test-case that I would be
comfortable including as a precise-output case (including the whole
thing verbatim would lock down a bunch of other irrelevant details and
cause test-update noise later). If we can find a more minimized example
I'm happy to include it as a filetest.
Fixes#5018.
* Replace resize+copy_from_slice with extend_from_slice
Vec::resize initializes the new space, which is wasted effort if we're
just going to call `copy_from_slice` on it immediately afterward. Using
`extend_from_slice` is simpler, and very slightly faster.
If the new size were bigger than the buffer we're copying from, then it
would make sense to initialize the excess. But it isn't: it's always
exactly the same size.
* Move helpers from Context to CompiledCode
These methods only use information from Context::compiled_code, so they
should live on CompiledCode instead.
* Remove an unnecessary #[cfg_attr]
There are other uses of `#[allow(clippy::too_many_arguments)]` in this
file, so apparently it doesn't need to be guarded by the "cargo-clippy"
feature.
* Fix a few comments
Two of these were wrong/misleading:
- `FunctionBuilder::new` does not clear the provided func_ctx. It does
debug-assert that the context is already clear, but I don't think
that's worth a comment.
- `switch_to_block` does not "create values for the arguments." That's
done by the combination of `append_block_params_for_function_params`
and `declare_wasm_parameters`.
* wasmtime-cranelift: Misc cleanups
The main change is to use the `CompiledCode` reference we already had
instead of getting it out of `Context` repeatedly. This removes a bunch
of `unwrap()` calls.
* wasmtime-cranelift: Factor out uncached compile
Resolve overlap in the RiscV64 backend by adding priorities to rules. Additionally, one test updated as a result of this work, as a peephole optimization for addition with immediates fires now.
Resolve overlap in the ISLE prelude and the x64 inst module by introducing new types that allow better sharing of extractor resuls, or falling back on priorities.
