From 3eae6ac8db4d9b5d09b7d9ab344e9baef73538cd Mon Sep 17 00:00:00 2001 From: lkcl Date: Wed, 27 Apr 2022 12:46:34 +0100 Subject: [PATCH] --- openpower/sv/biginteger/analysis.mdwn | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/openpower/sv/biginteger/analysis.mdwn b/openpower/sv/biginteger/analysis.mdwn index 6aebf874b..2583d7941 100644 --- a/openpower/sv/biginteger/analysis.mdwn +++ b/openpower/sv/biginteger/analysis.mdwn @@ -381,8 +381,8 @@ However when moving to 64-bit digits (desirable because the algorithm is `O(N^2)`) this in turn means that the estimate has to be computed from a *128* bit dividend and a 64-bit divisor. Such an operation simply does not exist in most Scalar 64-bit ISAs. Although Power ISA -comes close with `divdeu` placing the dividend in the upper half -of a 128-bit computation the lower half is zeros. Again Power ISA +comes close with `divdeu`, by placing the dividend in the upper half +of a 128-bit computation, the lower half is zero. Again Power ISA has a Packed SIMD instruction `vdivuq` which is a 128/128 (quad) divide, not a 128/64. Some investigation into soft-implementations of 128/128 or 128/64 divide show it to be typically -- 2.30.2