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Miri reports UB on division by zero with the LSX vdiv/vmod intrinsics when implemented via the portable simd_div/simd_rem helpers. [^1] Per clarification from the LoongArch ISA developers, the hardware defines that vdiv/vmod return 0 when the divisor is zero (this will be documented in the SIMD reference). This differs from the earlier assumption in PR rust-lang#2078, so the portable helpers are not a correct match. Switch back to the corresponding LLVM intrinsics so the Rust wrappers preserve the defined ISA behavior. [^1]: rust-lang#2221 (comment)
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Miri reports UB on division by zero with the LSX vdiv/vmod intrinsics when implemented via the portable simd_div/simd_rem helpers. 1
Per clarification from the LoongArch ISA developers, the hardware defines that vdiv/vmod return 0 when the divisor is zero (this will be documented in the SIMD reference). This differs from the earlier assumption in PR #2078, so the portable helpers are not a correct match.
Switch back to the corresponding LLVM intrinsics so the Rust wrappers preserve the defined ISA behavior.
Footnotes
https://github.com/rust-lang/stdarch/pull/2221#issuecomment-5688403926 ↩