Preserve FPRs as required by the Windows fastcall calling convention.
This exposes an implementation limit due to Cranelift's approach to stack layout, which conflicts with expectations Windows makes in SEH layout - functions where the Cranelift user desires fastcall unwind information, that require preservation of an ABI-reserved FPR, that have a stack frame 240 bytes or larger, now produce an error when compiled. Several wasm spectests were disabled because they would trip this limit. This is a temporary constraint that should be fixed promptly.
Co-authored-by: bjorn3 <bjorn3@users.noreply.github.com>
With this change, register banks can now be re-ordered and other components (e.g. unwinding, regalloc) will no longer break. The previous behavior assumed that GPR registers always started at `RegUnit` 0.
* Manually rename BasicBlock to BlockPredecessor
BasicBlock is a pair of (Ebb, Inst) that is used to represent the
basic block subcomponent of an Ebb that is a predecessor to an Ebb.
Eventually we will be able to remove this struct, but for now it
makes sense to give it a non-conflicting name so that we can start
to transition Ebb to represent a basic block.
I have not updated any comments that refer to BasicBlock, as
eventually we will remove BlockPredecessor and replace with Block,
which is a basic block, so the comments will become correct.
* Manually rename SSABuilder block types to avoid conflict
SSABuilder has its own Block and BlockData types. These along with
associated identifier will cause conflicts in a later commit, so
they are renamed to be more verbose here.
* Automatically rename 'Ebb' to 'Block' in *.rs
* Automatically rename 'EBB' to 'block' in *.rs
* Automatically rename 'ebb' to 'block' in *.rs
* Automatically rename 'extended basic block' to 'basic block' in *.rs
* Automatically rename 'an basic block' to 'a basic block' in *.rs
* Manually update comment for `Block`
`Block`'s wikipedia article required an update.
* Automatically rename 'an `Block`' to 'a `Block`' in *.rs
* Automatically rename 'extended_basic_block' to 'basic_block' in *.rs
* Automatically rename 'ebb' to 'block' in *.clif
* Manually rename clif constant that contains 'ebb' as substring to avoid conflict
* Automatically rename filecheck uses of 'EBB' to 'BB'
'regex: EBB' -> 'regex: BB'
'$EBB' -> '$BB'
* Automatically rename 'EBB' 'Ebb' to 'block' in *.clif
* Automatically rename 'an block' to 'a block' in *.clif
* Fix broken testcase when function name length increases
Test function names are limited to 16 characters. This causes
the new longer name to be truncated and fail a filecheck test. An
outdated comment was also fixed.
This commit fixes the build errors in the unwind info implementation for
the x86 ABI by changing `byteorder` to build `no_std`.
This copies two simple functions from the `WriteBytesExt` trait so that
we can easily write to a `Vec<u8>` with a particular endianness.
Fixes#1203.
* Implement emitting Windows unwind information for fastcall functions.
This commit implements emitting Windows unwind information for x64 fastcall
calling convention functions.
The unwind information can be used to construct a Windows function table at
runtime for JIT'd code, enabling stack walking and unwinding by the operating
system.
* Address code review feedback.
This commit addresses code review feedback:
* Remove unnecessary unsafe code.
* Emit the unwind information always as little endian.
* Fix comments.
A dependency from cranelift-codegen to the byteorder crate was added.
The byteorder crate is a no-dependencies crate with a reasonable
abstraction for writing binary data for a specific endianness.
* Address code review feedback.
* Disable default features for the `byteorder` crate.
* Add a comment regarding the Windows ABI unwind code numerical values.
* Panic if we encounter a Windows function with a prologue greater than 256
bytes in size.
