From 70dda033b8caf1bcfcd53302b6e04481a5b8b787 Mon Sep 17 00:00:00 2001 From: Jacob Lifshay Date: Fri, 14 Apr 2023 18:47:16 -0700 Subject: [PATCH] add lkcl's justification for fmin/fmax --- openpower/sv/rfc/ls013.mdwn | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/openpower/sv/rfc/ls013.mdwn b/openpower/sv/rfc/ls013.mdwn index 4b8ac5f8b..6341e572e 100644 --- a/openpower/sv/rfc/ls013.mdwn +++ b/openpower/sv/rfc/ls013.mdwn @@ -65,7 +65,9 @@ TODO SVP64 tree reduction needs a single instruction to work properly. 2. if you implement any of the FP min/max modes, the rest are not much more hardware. -3. FP min/max are rather complex to implement in software, the most commonly +3. TODO(lkcl): fill out: that using VSX may have different meaning (SVP64/VSX) + so it is *really* crucial to have SVP64/SFFS ops. +4. FP min/max are rather complex to implement in software, the most commonly used FP max function `fmax` from glibc compiled for SFFS is 32 (!) instructions. -- 2.30.2