BUG: Fix f64 trig accuracy; match SVML rounding DAGs - #10
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- Extended path: restructure final reconstruction to follow SVML's per-precision rounding DAG (f32/f64 pair the sin/cos correction terms differently) and regenerate approx.h so sigma is a signed power of two, keeping sigma*r exact
- Low path: give f64 cosine its own minimax fit matching __svml_cos_d_la and keep its fast path up to ~8388607*pi
- Non-FMA f64: add SplitMul (exact head product via 26-bit split) to replace the FMA product-error idiom in the high/extended paths and reduce with a descending 4-word pi/16, restoring sub-ULP accuracy
- Correct trig polynomial/scale/threshold commentsit log
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July 10, 2026 21:27
- Extended path: restructure final reconstruction to follow SVML's per-precision rounding DAG (f32/f64 pair the sin/cos correction terms differently) and regenerate approx.h so sigma is a signed power of two, keeping sigma*r exact - Low path: give f64 cosine its own minimax fit matching __svml_cos_d_la and keep its fast path up to ~8388607*pi - Non-FMA f64: add SplitMul (exact head product via 26-bit split) to replace the FMA product-error idiom in the high/extended paths and reduce with a descending 4-word pi/16, restoring sub-ULP accuracy - Correct trig polynomial/scale/threshold commentsit log
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