From 1f03a997e1814ae5c19500c724268d93eb8944d8 Mon Sep 17 00:00:00 2001 From: lkcl Date: Thu, 8 Aug 2019 13:39:44 +0100 Subject: [PATCH] --- ztrans_proposal.mdwn | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/ztrans_proposal.mdwn b/ztrans_proposal.mdwn index 17ca43510..a994bb138 100644 --- a/ztrans_proposal.mdwn +++ b/ztrans_proposal.mdwn @@ -123,3 +123,16 @@ RISC principle says "exclude LOG because it's covered by LOGP1 plus an ADD". Research needed to ensure that implementors are not compromised by such a decision + +# Dynamic accuracy CSR + +maybe a solution would be to add an extra field to the fp control csr to allow selecting one of several accurate or fast modes: + +- machine-learning-mode: fast as possible + -- maybe need additional requirements such as monotonicity for atanh? +- GPU-mode: accurate to within a few ULP + -- see Vulkan, OpenGL, and OpenCL specs for accuracy guidelines +- almost-accurate-mode: accurate to <1 ULP + (would 0.51 or some other value be better?) +- fully-accurate-mode: correctly rounded in all cases +- maybe more modes? -- 2.30.2