fix(runtime): TypedArray element-store coercion (ToUint32 modular) + f16 rounding#4746
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…f16 rounding - Element store for integer kinds now goes through a spec ToUint32/ToInt8/16/32 computed in f64 space: NaN/Inf/0 -> 0, truncate-toward-zero, reduce mod 2^32. The old `value as i64` path saturated at i64::MAX, so values past i64::MAX (e.g. 1e21) produced wrong low bits instead of wrapping modularly. - Float16 store converts directly from the f64 mantissa instead of via an intermediate f32, eliminating a double-rounding error at half-ulp boundaries (e.g. the smallest f16 subnormal collapsed to 0 instead of 2^-24). - Added unit tests for both.
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What
Fixes
built-ins/TypedArray(baseline 945/1328, 71.2%) — two element-store coercion bugs, with unit tests.Root causes
ToUint32/ToInt8/16/32computed in f64 space (NaN/±Inf/±0 → 0; truncate toward zero; reduce mod 2³²). The oldvalue as i64path saturated ati64::MAX, so values pasti64::MAX(e.g.1e21) produced wrong low bits instead of the spec's modular wrap.Files
typedarray/mod.rs,typedarray_half.rs(+ unit tests)Delta confirmed by post-merge resweep. (No version/CHANGELOG bump — maintainer folds in.)