Winch: implement rmw add ops#9990
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MarinPostma
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I can take this review. |
saulecabrera
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| &arg, | ||
| RmwOp::Add, | ||
| OperandSize::S16, | ||
| Some(ExtendKind::I32Extend16S), |
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The extension kinds used in this case are signed, however the spec states zero extension instead. I believe we need to augment ExtendKind to account for the missing unsigned extensions.
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that's because https://github.com/bytecodealliance/wasmtime/blob/main/winch/codegen/src/isa/x64/asm.rs#L395-L401 takes ExtendKind, even though movzx zero-extend. I can do that in a followup, if that's ok? i'll add variants for unsigned conversions, and update any affected code.
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I've extended ExtendKind here #10012 to include unsigned extends.
| Ok(()) | ||
| } | ||
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| pub(crate) fn atomic_rmw( |
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| pub(crate) fn atomic_rmw( | |
| pub(crate) fn emit_atomic_rmw( |
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| extend: Option<ExtendKind>, | ||
| ) -> Result<()> { | ||
| let operand = self.context.pop_to_reg(self.masm, None).unwrap(); | ||
| if let Some(addr) = self.emit_compute_heap_address(arg, size)? { |
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Just a note that this will require a rebase once #9987 lands and use emit_compute_heap_address_align_checked
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@saulecabrera I'll do all the rebases once #9987 is in |
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@saulecabrera rebase is done. I have also added a check to ensure that only valid extends are passed to |
| // It is only necessary to zero-extend when the operand is less than 32bits. | ||
| // x64 automatically zero-extend 32bits to 64bit. | ||
| Some( | ||
| extend @ (ExtendKind::I32Extend8S | ||
| | ExtendKind::I64Extend8S | ||
| | ExtendKind::I64Extend16S | ||
| | ExtendKind::I32Extend16S), | ||
| ) => { |
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I believe the check here needs updating? The code is emitting a zero extend but matching against a signed extend? Also I believe that to: (i) reduce duplication and (ii) avoid affecting compile time performance, we can entirely remove this check, since Cranelift's emission layer already takes care of it https://github.com/bytecodealliance/wasmtime/blob/main/cranelift/codegen/src/isa/x64/inst/emit.rs#L973.
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good catch i'll remove it
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impl read-modify-write add for winch:
i32.atomic.rmw8.add_ui32.atomic.rmw16.add_ui32.atomic.rmw.addi64.atomic.rmw8.add_ui64.atomic.rmw16.add_ui64.atomic.rmw32.add_ui64.atomic.rmw.add#9734