Cranelift/x64: fix register allocator metadata for 8-bit divides. #4332
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`idiv` on x86-64 only reads `rdx`/`edx`/`dx`/`dl` for divides with width greater than 8 bits; for an 8-bit divide, it reads the whole 16-bit divisor from `ax`, as our CISC ancestors intended. This PR fixes the metadata to avoid a regalloc panic (due to undefined `rdx`) in this case. Does not affect Wasmtime or other Wasm-frontend embedders.
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cfallin
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…tecodealliance#4332) `idiv` on x86-64 only reads `rdx`/`edx`/`dx`/`dl` for divides with width greater than 8 bits; for an 8-bit divide, it reads the whole 16-bit divisor from `ax`, as our CISC ancestors intended. This PR fixes the metadata to avoid a regalloc panic (due to undefined `rdx`) in this case. Does not affect Wasmtime or other Wasm-frontend embedders.
cfallin
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…tecodealliance#4332) `idiv` on x86-64 only reads `rdx`/`edx`/`dx`/`dl` for divides with width greater than 8 bits; for an 8-bit divide, it reads the whole 16-bit divisor from `ax`, as our CISC ancestors intended. This PR fixes the metadata to avoid a regalloc panic (due to undefined `rdx`) in this case. Does not affect Wasmtime or other Wasm-frontend embedders.
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* Cranelift/x64: fix register allocator metadata for 8-bit divides. (#4332) `idiv` on x86-64 only reads `rdx`/`edx`/`dx`/`dl` for divides with width greater than 8 bits; for an 8-bit divide, it reads the whole 16-bit divisor from `ax`, as our CISC ancestors intended. This PR fixes the metadata to avoid a regalloc panic (due to undefined `rdx`) in this case. Does not affect Wasmtime or other Wasm-frontend embedders. * Update RELEASES.md.
afonso360
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Jun 30, 2022
…tecodealliance#4332) `idiv` on x86-64 only reads `rdx`/`edx`/`dx`/`dl` for divides with width greater than 8 bits; for an 8-bit divide, it reads the whole 16-bit divisor from `ax`, as our CISC ancestors intended. This PR fixes the metadata to avoid a regalloc panic (due to undefined `rdx`) in this case. Does not affect Wasmtime or other Wasm-frontend embedders.
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idivon x86-64 only readsrdx/edx/dx/dlfor divides with widthgreater than 8 bits; for an 8-bit divide, it reads the whole 16-bit
divisor from
ax, as our CISC ancestors intended. This PR fixes themetadata to avoid a regalloc panic (due to undefined
rdx) in thiscase. Does not affect Wasmtime or other Wasm-frontend embedders.