fix(LLVM,riscv64): fix calling conventions for i32 type

[marxin]

There's a special requirement for the RISC-V SysV ABI:
https://five-embeddev.com/riscv-user-isa-manual/Priv-v1.12/rv64.html

The compiler and calling convention maintain an invariant that all 32-bit values are held in a sign-extended format in 64-bit registers.
Even 32-bit unsigned integers extend bit 31 into bits 63 through 32. Consequently, conversion between unsigned and signed 32-bit integers
is a no-op, as is conversion from a signed 32-bit integer to a signed 64-bit integer.

So far, we've been using X86_64SystemV for the RISC-V ABI, and so I copied it into a separate one, where extra param attributes are added. That's something we must address as part of #5943. On top of that I decided to put some common functionality into the Abi trait itself.

@wakabat can you give it a try?

Fixes: #5977

[Copilot]

Pull request overview

This pull request fixes calling conventions for the i32 type on RISC-V 64-bit platforms to comply with the RISC-V SysV ABI requirement that all 32-bit values must be held in sign-extended format in 64-bit registers.

Changes:

• Introduces a new RISC-V SystemV ABI implementation with proper handling of i32 sign-extension requirements
• Adds signext and noundef attributes to all i32 parameters in function declarations and call sites for RISC-V 64-bit targets
• Refactors common ABI functionality into default trait implementations to reduce code duplication

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
lib/compiler-llvm/src/abi/riscv_systemv.rs	New file implementing RISC-V SystemV ABI with i32 sign-extension handling
lib/compiler-llvm/src/abi/mod.rs	Refactors common ABI methods into default trait implementations; adds RISC-V ABI selection
lib/compiler-llvm/src/abi/x86_64_systemv.rs	Removes duplicate code now in default trait implementations
lib/compiler-llvm/src/abi/aarch64_systemv.rs	Removes duplicate code now in default trait implementations
lib/compiler-llvm/src/translator/intrinsics.rs	Adds target_triple parameter and applies i32 attributes to intrinsic functions for RISC-V
lib/compiler-llvm/src/translator/code.rs	Adds build_call_with_param_attributes helper to apply i32 attributes at call sites for RISC-V
lib/compiler-llvm/src/trampoline/wasm.rs	Updates Intrinsics::declare calls with new target_triple parameter

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[syrusakbary]

I find a bit strange that this logic lives here, it feels a bit of a hack.
Do you think this could be improved?

[marxin]

Good point! We can do better by using the https://thedan64.github.io/inkwell/inkwell/intrinsics/struct.Intrinsic.html#method.find API, that should give us a properly annotated declaration that hopefully takes target ABI into account.

[wakabat]

Hey thanks for this change! I have run all the tests on our side using Rust 1.92.0, and they all pass. So as far as our tests, this change did resolve the bug in #5977

[marxin]

Cool, thanks for the confirmation.