Tue Ly 15b9380dfd [libc] Change sinf range reduction to mod pi/16 to be shared with cosf. ... Change `sinf` range reduction to mod pi/16 to be shared with `cosf`. Previously, `sinf` used range reduction `mod pi`, but this cannot be used to implement `cosf` since the minimax algorithm for `cosf` does not converge due to critical points at `pi/2`. In order to be able to share the same range reduction functions for both `sinf` and `cosf`, we change the range reduction to `mod pi/16` for the following reasons: - The table size is sufficiently small: 32 entries for `sin(k * pi/16)` with `k = 0..31`. It could be reduced to 16 entries if we treat the final sign separately, with an extra multiplication at the end. - The polynomials' degrees are reduced to 7/8 from 15, with extra computations to combine `sin` and `cos` with trig sum equality. - The number of exceptional cases reduced to 2 (with FMA) and 3 (without FMA). - The latency is reduced while maintaining similar throughput as before. Reviewed By: zimmermann6 Differential Revision: https://reviews.llvm.org/D130629		2022-07-27 12:23:36 -04:00
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arcanist	[utils] Don't print username in arcanist clang format message	2021-05-14 14:33:00 +00:00
bazel	[libc] Change sinf range reduction to mod pi/16 to be shared with cosf.	2022-07-27 12:23:36 -04:00