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Re: [PATCH 03/10] Improve performance of sinf and cosf
- From: Joseph Myers <joseph at codesourcery dot com>
- To: Szabolcs Nagy <szabolcs dot nagy at arm dot com>
- Cc: GNU C Library <libc-alpha at sourceware dot org>, <nd at arm dot com>, Wilco Dijkstra <Wilco dot Dijkstra at arm dot com>
- Date: Mon, 13 Aug 2018 19:46:26 +0000
- Subject: Re: [PATCH 03/10] Improve performance of sinf and cosf
- References: <d4963b4e-0013-adaf-df2f-698cf421a487@arm.com> <480576b5-fbb7-39b2-d80c-80c8931fde21@arm.com>
On Fri, 6 Jul 2018, Szabolcs Nagy wrote:
> +/* Fast cosf implementation. Worst-case ULP is 0.56072, maximum relative
> + error is 0.5303p-23. A single-step signed range reduction is used for
> + small values. Large inputs have their range reduced using fast integer
> + arithmetic.
This needs the same fix as for sincosf to avoid the invalid constant
0.5303p-23.
> +/* Fast sinf implementation. Worst-case ULP is 0.56072, maximum relative
> + error is 0.5303p-23. A single-step signed range reduction is used for
> + small values. Large inputs have their range reduced using fast integer
> + arithmetic.
Likewise.
OK with those fixes.
As previously discussed, a followup to eliminate __kernel_sinf /
__kernel_cosf may well make sense.
--
Joseph S. Myers
joseph@codesourcery.com