Changes in masm.rs

39e910be - [44.0.0] Merged backports for security advisories (#13007)

Thu, 09 Apr 2026 17:40:49 +0000

[44.0.0] Merged backports for security advisories (#13007)* fix(environ): repair unsound StringPool::try_clone()The 43.0 release introduced a soundness bug in StringPool::try_clone(): thecloned map retains &'static str keys pointing into the original pool'sstrings storage. Once the original Linker is dropped those keys dangle.Cloning a Linker, then dropping the original one, leaves a linker whoseregistered imports could no longer be found, causing instantiation tofail with "unknown import".Signed-off-by: Flavio Castelli * Fix pooling allocator predicate to reset VM permissionsThis commit fixes a mistake that was introduced in #9583 where the logicto reset a linear memory slot in the pooling allocator used the wrongpredicate. Specifically VM permissions must be reset if virtual memorycan be relied on at all, and the preexisting predicate of`can_elide_bounds_check` was an inaccurate representation of this. Thecorrect predicate to check is `can_use_virtual_memory`.* winch: Fix the type of the `table.size` output registerThis commit corrects the tagged size of the output of the `table.size`instruction. Previously this was hardcoded as a 32-bit integer insteadof consulting the table's index type to use theindex-type-sized-register instead.* winch: Fix a host panic when executing `table.fill`This commit fixes a possible panic when a Winch-compiled module executesthe `table.fill` instruction. Refactoring in #11254 updated Craneliftbut forgot to update Winch meaning that Winch's indices were still usingthe module-level indices instead of the `DefinedTableIndex` space. Thisadds some tests and updates Winch's translation to use preexistinghelpers.* x64: Fix `f64x2.splat` without SSE3Don't sink a load into `pshufd` which loads 16 bytes, instead force`put_in_xmm` to ensure only 8 bytes are loaded.* Properly verify alignment in string transcodingThis commit updates string transcoding between guest modules to properlyverify alignment. Previously alignment was only verified on the firstallocation, not reallocations, which is not spec-compliant. Thisadditionally fixes a possible host panic when dealing with unalignedpointers.* Fix type confusion in AArch64 amode RegScaled folding* winch: Add add_uextend to perform explicit extension when needed.This commit fixes an out-of-bounds access caused by the lack zeroextension in the code responsible for calculating the heap address forloads/stores.This issue manifests in aarch64 (unlike x64) given that no automaticextension is performed, resulting in an out-of-bounds access.An alternative approach is to emit an extend for the index, howeverthis approach is preferred given that it gives the MacroAssemblerlayer better control of how to lower addition, e.g., in aarch64 we caninline the desired extension in a single instruction.* winch: Correctly type the result of table.growThis commit fixes an out-of-bounds access caused by the lack of typenarrowing from the `table.grow` builtin. Without explicit narrowing,the type is treated as 64-bit value, which could cause issues whenpaired with loads/stores.* Review comments* Properly handle table index typesOnly narrow when dealing with the 64-bit pointer/32-bit tables* Fix panic with out-of-bounds flags in `Value`This commit fixes a panic when a component model `Value` is lifted froma flags value which specifies out-of-bounds bits as 1. This is specifiedin the component model to ignore the out-of-bounds bits, which `flags!`correctly did (and thus `bindgen!`), but `Value` treated out-of-boundsbits as a panic due to indexing an array.* Fix bounds checks in FACT's `string_to_compact` methodWe need to bounds check the source byte length, not the number of code units.* Add missing realloc validation in string transcodingThis commit adds a missing validation that a return value of `realloc`is inbounds during string transcoding. This was accidentally missing onthe transcoding path from `utf8` to `latin1+utf16` which meant that anearly-raw pointer could get passed to the host to perform thetranscode.* winch: Refine zero extension heuristicThis commit refines the zero extension heuristic such that itunconditionally emits a zero extension when dealing with 32-bitheaps. This eliminates any ambiguity related to the value of thememory indices across ISAs.* Fix failure on 32-bit* Fix miri test---------Signed-off-by: Flavio Castelli Co-authored-by: Flavio Castelli Co-authored-by: Shun Kashiwa Co-authored-by: Saúl Cabrera Co-authored-by: Nick Fitzgerald List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

b112bb85 - Migrate winch-codegen to `wasmtime_environ::error` (#12297)

Fri, 09 Jan 2026 19:20:48 +0000

Migrate winch-codegen to `wasmtime_environ::error` (#12297) List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

b73105bf - Reduce scope of scratch registers for SIMD shifts (#11935)

Fri, 24 Oct 2025 20:49:30 +0000

Reduce scope of scratch registers for SIMD shifts (#11935) List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

ab76f64b - Make `vm::Instance::get_defined_memory` safe (#11211)

Thu, 10 Jul 2025 16:18:57 +0000

Make `vm::Instance::get_defined_memory` safe (#11211)This is a small step forward to making `vm::Instance` safe internally.Notably the `get_defined_memory` helper now returns a safe mutablereference instead of a raw pointer. This is then additionally coupledwith the canonicalization of always working with memories as "instanceplus defined memory index" instead of "instance plus memory index". Thisenables removing some unsafe `VMContext` to `Instance` conversion aswell. This change, however, required updating libcalls to special-casewhen an imported memory is operated on to load the vmcontext/index inthe libcall itself.This change notably does not update the `memory_init` libcall just yetdue to the fact that the `DataIndex` is relative to the owning instanceeven if the memory is owned by a different instance (e.g. it'simported). Otherwise this chips away at some of the `unsafe` related tomemory/table management in `vm::Instance`. List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

ffef1ed1 - winch: Use `Masm::with_scratch` in ISA-agnostic code (#10998)

Tue, 10 Jun 2025 17:48:38 +0000

winch: Use `Masm::with_scratch` in ISA-agnostic code (#10998)* winch: Use `Masm::with_scratch` in ISA-agnostic codeThis commit is a follow-up tohttps://github.com/bytecodealliance/wasmtime/pull/10989; it migratesall the uses of the scratch register to use `Masm::with_scratch`. Thiscommit also updates the tests that can fail / are ignored, since manyof the bugs were introduced by accidental clobbers to scratchregisters.Even though this change doesn't introduce any functional changes, thedisassembly changes in aarch64 are due to the usage of x17 as an extrascratch registers. The updates in x64 dissembly are related to offset changes.* Use `with_scratch!` in `pop_to_addr`* Remove dead code* Apply cargo fmt* Remove `imports.wast` from ignore list* Use the new version of `Masm::with_scratch`* Introduce `Masm::with_scratch_for`Helper to derive the register class needed for a particular Wasm value type* Format List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

f3c320d8 - winch: Generalize `with_scratch` function (#10997)

Tue, 10 Jun 2025 15:05:22 +0000

winch: Generalize `with_scratch` function (#10997)* Support any return value, not just `Result<()>`* Use `FnOnce` instead of `FnMut`This meant that many `Ok(())` values could be dropped, but other valuesusing `?` needed to explicitly annotate the return type which is done byreturning `anyhow::Ok(())` to force the error type. List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

dacd33b0 - winch: Simplify constant handling, part 2/N (#10989)

Mon, 09 Jun 2025 22:54:51 +0000

winch: Simplify constant handling, part 2/N (#10989)* winch: Introduce register allocation for scratch registersThis commit introduces a register allocator for scratch registers. Theobjective of this change is to make it generally safer to work withscratch registers and prevent accidental clobbering of said registers.This approach also has the advantage that allows for a more naturalabstraction over ISA-dependent scratch register definitions, e.g., wecan easily encode that fact that in aarch64 x16 and x17 are consideredscratch registers, while in x64 Winch's ABI defines a single globalscratch register.* winch: Hook up the scratch allocator in each of the backendsThis commit makes use of the scratch register allocator in both thex64 and aarch64 backends for immediate value loading.Given that the MacroAssembler is the boundary between ISA-agnosticcode and ISA-dependent code, it seems to be the natural location forthis allocator to live.The allocator gives exclusive access to a scratch register of aparticular class, through the `Masm::with_scratch` method. Note thatthe semantics of this allocator don't involve spilling or any otherform of register availability resolution. If a register is requestedand it's not available, this method will panic.* Apply `cargo fmt`* Update disassembly testsEven though the entire change doens't contain major funcitonalchanges, a side effect of improving the constant handling in aarch64is that we perform better instruction selection for instructions thatdeal with immediattes, improving the generated code in some cases.* Review edits List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

89419ec2 - winch: Move the `AtomicWaitKind` definition to the MacroAssembler (#10853)

Wed, 28 May 2025 17:34:06 +0000

winch: Move the `AtomicWaitKind` definition to the MacroAssembler (#10853)This commit is a small refactoring which moves the definition of the`AtomicWaitKind` enum to the `MacroAssembler`, to ensure with theother operation kind definitions. List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

703871a2 - Enable the `useless_conversion` Clippy lint (#10838)

Tue, 27 May 2025 16:49:22 +0000

Enable the `useless_conversion` Clippy lint (#10838)* Enable the `useless_conversion` Clippy lintWe've got lots of types in Wasmtime and convert between them quite alot, but often over time conversions become unnecessary throughrefactorings or similar. This will hopefully enable us to clean up someconversions as they come up to try to have as few as possible ideally.* Review comments List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

90ac295e - Update Wasmtime to the 2024 Rust Edition (#10806)

Mon, 19 May 2025 16:40:55 +0000

Update Wasmtime to the 2024 Rust Edition (#10806)* Update Wasmtime to the 2024 Rust EditionNow that our MSRV supports the 2024 edition it's possible to make thisswitch. This commit moves Wasmtime to the 2024 Edition to keepup-to-date with Rust idioms and access many of the edition featuresexclusive to the 2024 edition.prtest:full* Reformat with the 2024 edition List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

ee275a89 - Switch to using Wasmtime-style builtins for ceil, floor, etc. (#10657)

Thu, 24 Apr 2025 05:06:05 +0000

Switch to using Wasmtime-style builtins for ceil, floor, etc. (#10657)* Switch to using Wasmtime-style builtins for ceil, floor, etc.With this patch, all emitted calls are Wasmtime-style builtins, ratherthan Cranelift-style libcalls. This ensures that all calls fromCranelift-generated code into Wasmtime host code use the same mechanism,and eliminates the relocation handling code for the libcall mechanism.* Update tests.* Avoid using x86_pshufb on non-x86 platforms.* Revert unneeded f32/f64 changes in Pulley.* Define i8x16 as an unconstructible type if sse isn't available.* Delete the setters too.* Fix f32/f64 setters.* Test with prtest:full.prtest:full* Support fma.* Return true for `has_native_fma` on pulley.This works because pulley already has code implementing fma. This avoidsneeding to marshal f32x4 values into builtin function calls on pulley.* Update tests. List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

944ae828 - Winch: Fix issue with multivalue returns (#10370)

Wed, 12 Mar 2025 11:48:35 +0000

Winch: Fix issue with multivalue returns (#10370) List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

665c098a - chore: remove redundant words in comment (#10354)

Fri, 07 Mar 2025 12:58:50 +0000

chore: remove redundant words in comment (#10354)Signed-off-by: NinaLua List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

c56ff13f - Winch: Fix extadd implementations (#10337)

Thu, 06 Mar 2025 15:23:45 +0000

Winch: Fix extadd implementations (#10337)* Winch: Fix extadd implementations* Add new Wast test to excluded tests List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

89ebd453 - winch(aarch64): Fix effective address calculation (#10297)

Thu, 27 Feb 2025 18:59:28 +0000

winch(aarch64): Fix effective address calculation (#10297)* winch(aarch64): Fix effective address calculation`load_addr` should load the effective address, not the contents of theaddress.This was causing issues with indirect function calls.* Rename `load_addr` to `compute_addr` List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

898b0feb - Winch: Add load_zero instructions for x64 with AVX (#10288)

Tue, 25 Feb 2025 16:29:56 +0000

Winch: Add load_zero instructions for x64 with AVX (#10288) List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

b0319ebc - Winch: Add implementations for pmin and pmax for x64 with AVX (#10284)

Tue, 25 Feb 2025 15:45:03 +0000

Winch: Add implementations for pmin and pmax for x64 with AVX (#10284) List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

1f24222f - Winch: Add min and max for SIMD floats for x64 with AVX (#10271)

Tue, 25 Feb 2025 11:55:24 +0000

Winch: Add min and max for SIMD floats for x64 with AVX (#10271) List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

acef4083 - Winch: Add SIMD float arithmetic support for x64 with AVX (#10247)

Thu, 20 Feb 2025 20:58:11 +0000

Winch: Add SIMD float arithmetic support for x64 with AVX (#10247)* Winch: Add SIMD float arithmetic support for x64 with AVX* Add ensure_has_avx to v128_neg method List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs

fb7dd612 - Winch: Implement float rounding instructions for x64 with AVX (#10243)

Thu, 20 Feb 2025 15:36:28 +0000

Winch: Implement float rounding instructions for x64 with AVX (#10243) List of files: /wasmtime-44.0.1/winch/codegen/src/masm.rs