This adds support for StructArgument on s390x. The ABI for this
platform requires that the address of the buffer holding the copy
of the struct argument is passed from caller to callee as hidden
pointer, using a register or overflow stack slot.
To implement this, I've added an optional "pointer" filed to
ABIArg::StructArg, and code to handle the pointer both in common
abi_impl code and the s390x back-end.
One notable change necessary to make this work involved the
"copy_to_arg_order" mechanism. Currently, for struct args
we only need to copy the data (and that need to happen before
setting up any other args), while for non-struct args we only
need to set up the appropriate registers or stack slots.
This order is ensured by sorting the arguments appropriately
into a "copy_to_arg_order" list.
However, for struct args with explicit pointers we need to *both*
copy the data (again, before everything else), *and* set up a
register or stack slot. Since we now need to touch the argument
twice, we cannot solve the ordering problem by a simple sort.
Instead, the abi_impl common code now provided *two* callbacks,
emit_copy_regs_to_buffer and emit_copy_regs_to_arg, and expects
the back end to first call copy..to_buffer for all args, and
then call copy.._to_arg for all args. This required updates
to all back ends.
In the s390x back end, in addition to the new ABI code, I'm now
adding code to actually copy the struct data, using the MVC
instruction (for small buffers) or a memcpy libcall (for larger
buffers). This also requires a bit of new infrastructure:
- MVC is the first memory-to-memory instruction we use, which
needed a bit of memory argument tweaking
- We also need to set up the infrastructure to emit libcalls.
(This implements the first half of issue #4565.)
Give the user the option to sign and to authenticate function
return addresses with the operations introduced by the Pointer
Authentication extension to the Arm instruction set architecture.
Copyright (c) 2021, Arm Limited.
I essentially add these same logs back in every time I'm debugging something
related to this fuzz target or `externref`s in general. Probably like 5 times
I've added roughly these logs. We should just make them available whenever we
need them via `RUST_LOG=wasmtime_runtime=trace`.
This also changes a couple `if let`s to `unwrap`s that are now infallible after
* Cranelift: Add instructions for getting the current stack/frame pointers and return address
This is the initial part of https://github.com/bytecodealliance/wasmtime/issues/4535
* x64: Remove `Amode::RbpOffset` and use `Amode::ImmReg` instead
We just special case getting operands from `Amode`s now.
* Fix s390x `get_return_address`; require `preserve_frame_pointers=true`
* Assert that `Amode::ImmRegRegShift` doesn't use rbp/rsp
* Handle non-allocatable registers in Amode::with_allocs
* Use "stack" instead of "r15" on s390x
* r14 is an allocatable register on s390x, so it shouldn't be used with `MovPReg`
The gen_copy_arg_to_regs routine currently ignores argument extension
flags when loading incoming arguments. This causes a problem with
stack arguments on big-endian systems, since the argument address
points to the word on the stack as extended by the caller, but the
generated code only loads the inner type from the address, causing
it to receive an incorrect value. (This happens to work on little-
endian systems.)
Fixed by loading extended arguments as full words.
* Cranellift: remove Baldrdash support and related features.
As noted in Mozilla's bugzilla bug 1781425 [1], the SpiderMonkey team
has recently determined that their current form of integration with
Cranelift is too hard to maintain, and they have chosen to remove it
from their codebase. If and when they decide to build updated support
for Cranelift, they will adopt different approaches to several details
of the integration.
In the meantime, after discussion with the SpiderMonkey folks, they
agree that it makes sense to remove the bits of Cranelift that exist
to support the integration ("Baldrdash"), as they will not need
them. Many of these bits are difficult-to-maintain special cases that
are not actually tested in Cranelift proper: for example, the
Baldrdash integration required Cranelift to emit function bodies
without prologues/epilogues, and instead communicate very precise
information about the expected frame size and layout, then stitched
together something post-facto. This was brittle and caused a lot of
incidental complexity ("fallthrough returns", the resulting special
logic in block-ordering); this is just one example. As another
example, one particular Baldrdash ABI variant processed stack args in
reverse order, so our ABI code had to support both traversal
orders. We had a number of other Baldrdash-specific settings as well
that did various special things.
This PR removes Baldrdash ABI support, the `fallthrough_return`
instruction, and pulls some threads to remove now-unused bits as a
result of those two, with the understanding that the SpiderMonkey folks
will build new functionality as needed in the future and we can perhaps
find cleaner abstractions to make it all work.
[1] https://bugzilla.mozilla.org/show_bug.cgi?id=1781425
* Review feedback.
* Fix (?) DWARF debug tests: add `--disable-cache` to wasmtime invocations.
The debugger tests invoke `wasmtime` from within each test case under
the control of a debugger (gdb or lldb). Some of these tests started to
inexplicably fail in CI with unrelated changes, and the failures were
only inconsistently reproducible locally. It seems to be cache related:
if we disable cached compilation on the nested `wasmtime` invocations,
the tests consistently pass.
* Review feedback.
* Move `emit_to_memory` to `MachCompileResult`
This small refactoring makes it clearer to me that emitting to memory
doesn't require anything else from the compilation `Context`. While it's
a trivial change, it's a small public API change that shouldn't cause
too much trouble, and doesn't seem RFC-worthy. Happy to hear different
opinions about this, though!
* hide the MachCompileResult behind a method
* Add a `CompileError` wrapper type that references a `Function`
* Rename MachCompileResult to CompiledCode
* Additionally remove the last unsafe API in cranelift-codegen
* Cranelift: Don't `emit` inside lowering rules in aarch64
The lowering rules should be "pure" and side-effect free, using helpers defined
in `inst.isle` to perform actual side effects like emitting instructions.
* Cranelift: use 80 width for section separators in aarch64 lowering rules
* Support shadowing in isle
* Re-run the isle build.rs if the examples change
* Print error messages when isle tests fail
* Move run tests
* Refactor `let` uses that don't need to introduce unique names
* cranelift: Add MinGW `fma` regression tests
* cranelift: Fix FMA in interpreter
* cranelift: Add separate `fma` test suite for the interpreter
The interpreter can run `fma.clif` on most platforms, however on
`x86_64-pc-windows-gnu` we use libm which has issues with some inputs.
We should delete `fma-interpreter.clif` and enable the interpreter on
the main `fma.clif` file once those are fixed.
Ported the existing implementation of the following Opcodes for AArch64
to ISLE:
- `Fence`
- `IsNull`
- `IsInvalid`
- `Debugtrap`
Copyright (c) 2022 Arm Limited
* cranelift: Reorganize test suite
Group some SIMD operations by instruction.
* cranelift: Deduplicate some shift tests
Also, new tests with the mod behaviour
* aarch64: Lower shifts with mod behaviour
* x64: Lower shifts with mod behaviour
* wasmtime: Don't mask SIMD shifts
DHAT reports that when compiling the Spidermonkey Sightglass benchmark,
there are over 100k of these Vec allocations, averaging less than 4
bytes, and with an average lifetime of only about 500 instructions.
This function is only called from one place, which immediately converts
it into an iterator. So this commit just returns the iterator that was
previously being collected into a Vec. The iterator has to borrow from
the DataFlowGraph, so this would change borrow-check results, but in the
one caller that turns out to be okay.
(That sole caller is in cranelift/codegen/src/machinst/lower.rs, in
Lower::lower().)
According to Sightglass, this is a compile-time improvement of between
2% and 12% on the Spidermonkey benchmark:
instantiation :: nanoseconds :: benchmarks/spidermonkey/benchmark.wasm
Δ = 14628.76 ± 10318.59 (confidence = 99%)
main-0e6ffd024.so is 0.87x to 0.98x faster than no-small-vecs.so!
no-small-vecs.so is 1.02x to 1.14x faster than main-0e6ffd024.so!
[142023 187464.24 301522] main-0e6ffd024.so
[103742 172835.48 263917] no-small-vecs.so
compilation :: nanoseconds :: benchmarks/spidermonkey/benchmark.wasm
Δ = 362392705.93 ± 267070467.06 (confidence = 99%)
main-0e6ffd024.so is 0.89x to 0.98x faster than no-small-vecs.so!
no-small-vecs.so is 1.02x to 1.12x faster than main-0e6ffd024.so!
[3655734131 5522594697.83 6471126699] main-0e6ffd024.so
[3278129811 5160201991.90 5810600015] no-small-vecs.so
* x64: Add VEX Instruction Encoder
This uses a similar builder pattern to the EVEX Encoder.
Does not yet support memory accesses.
* x64: Add FMA Flag
* x64: Implement SIMD `fma`
* x64: Use 4 register Vex Inst
* x64: Reorder VEX pretty print args
* Allow 64-bit vectors and implement for interpreter
The AArch64 backend already supports 64-bit vectors; this simply allows
instructions to make use of that.
Implemented support for 64-bit vectors within the interpreter to allow
interpret runtests to use them.
Copyright (c) 2022 Arm Limited
* Disable 64-bit SIMD `iaddpairwise` tests on s390x
Copyright (c) 2022 Arm Limited
* [AArch64] Port SIMD narrowing to ISLE
Fvdemote, snarrow, unarrow and uunarrow.
Also refactor the aarch64 instructions descriptions to parameterize
on ScalarSize instead of using different opcodes.
The zero_value pure constructor has been introduced and used by the
integer narrow operations and it replaces, and extends, the compare
zero patterns.
Copright (c) 2022, Arm Limited.
* use short 'if' patterns
This enables more runtests to be executed on s390x. Doing so
uncovered a two back-end bugs, which are fixed as well:
- The result of cls was always off by one.
- The result of popcnt.i16 has uninitialized high bits.
In addition, I found a bug in the load-op-store.clif test case:
v3 = heap_addr.i64 heap0, v1, 4
v4 = iconst.i64 42
store.i32 v4, v3
This was clearly intended to perform a 32-bit store, but
actually performs a 64-bit store (it seems the type annotation
of the store opcode is ignored, and the type of the operand
is used instead). That bug did not show any noticable symptoms
on little-endian architectures, but broke on big-endian.
* cranelift: Restrict `br_table` to `i32` indices
In #4498 it was proposed that we should only accept `i32` indices
to `br_table`. The rationale for this is that larger types lead the
users to a false sense of flexibility (since we don't support jump
tables larger than u32's), and narrower types are not well tested
paths that would be safer if we removed them.
* cranelift: Reduce directly from i128 to i32 in Switch
Converted the existing implementations for the following opcodes to ISLE
on AArch64:
- `sqrt`
- `fneg`
- `fabs`
- `fpromote`
- `fdemote`
- `ceil`
- `floor`
- `trunc`
- `nearest`
Copyright (c) 2022 Arm Limited
On s390x, we do not have a frame pointer that can be used to chain
stack frames for easy unwinding. Instead, our ABI defines a stack
"backchain" mechanism that can be used to the same effect.
This PR uses that backchain mechanism to implement the new
preserve_frame_pointers flags introduced here:
https://github.com/bytecodealliance/wasmtime/pull/4469
This includes some changes from @bnjbvr to the trace-logging/annotation
to reduce overhead when logging is enabled but only non-RA2 subsystems
are at `Trace` level.
* Skip new `table_ops` test under emulation
When emulating we already have to disable most pooling-allocator related
tests so this commit carries over that logic to the new fuzz test which
may run some configurations with the pooling allocator depending on the
random input.
* Fix panics in s390x codegen related to aliases
This commit fixes an issue introduced as part of the fix for
GHSA-5fhj-g3p3-pq9g. The `reftyped_vregs` list given to `regalloc2` is
not allowed to have duplicates in it and while the list originally
doesn't have duplicates once aliases are applied the list may have
duplicates. The fix here is to perform another pass to remove duplicates
after the aliases have been processed.
* Improve cranelift disassembly of stack maps
Print out extra information about stack maps such as their contents and
other related metadata available. Additionally also print out addresses
in hex to line up with the disassembly otherwise printed as well.
* Improve the `table_ops` fuzzer
* Generate more instructions by default
* Fix negative indices appearing in `table.{get,set}`
* Assert that the traps generated are expected to prevent accidental
other errors reporting a fuzzing success.
* Fix `reftype_vregs` reported to `regalloc2`
This fixes a mistake in the register allocation of Cranelift functions
where functions using reference-typed arguments incorrectly report which
virtual registers are reference-typed values if there are vreg aliases
in play. The fix here is to apply the vreg aliases to the final list of
reftyped regs which is eventually passed to `regalloc2`.
The main consequence of this fix is that functions which previously
accidentally didn't have correct stack maps should now have the missing
stack maps.
* Add a test that `table_ops` gc's eventually
* Add a comment about new alias resolution
* Update crates/fuzzing/src/oracles.rs
Co-authored-by: Nick Fitzgerald <fitzgen@gmail.com>
* Add some comments
Co-authored-by: Nick Fitzgerald <fitzgen@gmail.com>
Preserving frame pointers -- even inside leaf functions -- makes it easy to
capture the stack of a running program, without requiring any side tables or
metadata (like `.eh_frame` sections). Many sampling profilers and similar tools
walk frame pointers to capture stacks. Enabling this option will play nice with
those tools.
Converted the existing implementations for the following Opcodes to ISLE on AArch64:
- `fadd`
- `fsub`
- `fmul`
- `fdiv`
- `fmin`
- `fmax`
- `fmin_pseudo`
- `fmax_pseudo`
Copyright (c) 2022 Arm Limited
This adds full support for all Cranelift SIMD instructions
to the s390x target. Everything is matched fully via ISLE.
In addition to adding support for many new instructions,
and the lower.isle code to match all SIMD IR patterns,
this patch also adds ABI support for vector types.
In particular, we now need to handle the fact that
vector registers 8 .. 15 are partially callee-saved,
i.e. the high parts of those registers (which correspond
to the old floating-poing registers) are callee-saved,
but the low parts are not. This is the exact same situation
that we already have on AArch64, and so this patch uses the
same solution (the is_included_in_clobbers callback).
The bulk of the changes are platform-specific, but there are
a few exceptions:
- Added ISLE extractors for the Immediate and Constant types,
to enable matching the vconst and swizzle instructions.
- Added a missing accessor for call_conv to ABISig.
- Fixed endian conversion for vector types in data_value.rs
to enable their use in runtests on the big-endian platforms.
- Enabled (nearly) all SIMD runtests on s390x. [ Two test cases
remain disabled due to vector shift count semantics, see below. ]
- Enabled all Wasmtime SIMD tests on s390x.
There are three minor issues, called out via FIXMEs below,
which should be addressed in the future, but should not be
blockers to getting this patch merged. I've opened the
following issues to track them:
- Vector shift count semantics
https://github.com/bytecodealliance/wasmtime/issues/4424
- is_included_in_clobbers vs. link register
https://github.com/bytecodealliance/wasmtime/issues/4425
- gen_constant callback
https://github.com/bytecodealliance/wasmtime/issues/4426
All tests, including all newly enabled SIMD tests, pass
on both z14 and z15 architectures.
* Implement `iabs` in ISLE (AArch64)
Converts the existing implementation of `iabs` for AArch64 into ISLE,
and fixes support for `iabs` on scalar values.
Copyright (c) 2022 Arm Limited.
* Improve scalar `iabs` implementation.
Also introduces `CSNeg` instruction.
Copyright (c) 2022 Arm Limited
* Convert `scalar_to_vector` to ISLE (AArch64)
Converted the exisiting implementation of `scalar_to_vector` for AArch64 to
ISLE.
Copyright (c) 2022 Arm Limited
* Add support for floats and fix FpuExtend
- Added rules to cover `f32 -> f32x4` and `f64 -> f64x2` for
`scalar_to_vector`
- Added tests for `scalar_to_vector` on floats.
- Corrected an invalid instruction emitted by `FpuExtend` on 64-bit
values.
Copyright (c) 2022 Arm Limited
