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Re: [PATCH 3/7] sin/cos slow paths: remove slow paths from small range reduction
- From: Joseph Myers <joseph at codesourcery dot com>
- To: Wilco Dijkstra <Wilco dot Dijkstra at arm dot com>
- Cc: "libc-alpha at sourceware dot org" <libc-alpha at sourceware dot org>, nd <nd at arm dot com>
- Date: Thu, 22 Mar 2018 22:28:05 +0000
- Subject: Re: [PATCH 3/7] sin/cos slow paths: remove slow paths from small range reduction
- References: <DB6PR0801MB20536EF05DE5CFE1BD1078C583AA0@DB6PR0801MB2053.eurprd08.prod.outlook.com>
On Wed, 21 Mar 2018, Wilco Dijkstra wrote:
> This patch improves the accuracy of the range reduction. When the input is
> large (2^27) and very close to a multiple of PI/2, using 110 bits of PI is not
> enough. Improve range reduction accuracy to 136 bits. As a result the special
> checks for results close to zero can be removed. The ULP of the polynomials is
> at worst 0.55ULP, so there is no reason for the slow functions, and they can be
> removed.
OK.
--
Joseph S. Myers
joseph@codesourcery.com