From 5ba384fc3bfe5ccf5826dbbb31822ac7b8587f39 Mon Sep 17 00:00:00 2001 From: lkcl Date: Sun, 25 Sep 2022 10:04:44 +0100 Subject: [PATCH] --- openpower/sv/overview/discussion.mdwn | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/openpower/sv/overview/discussion.mdwn b/openpower/sv/overview/discussion.mdwn index ec3104123..a689cf478 100644 --- a/openpower/sv/overview/discussion.mdwn +++ b/openpower/sv/overview/discussion.mdwn @@ -12,7 +12,7 @@ Industry-standard convention, LSB0. The confusion arises from the possibility of MSB0 numbering being potentially applicable to: * bits -* bytes +* bytes, halfwords, words, doublewords and quadwords * register numbers * element numbers @@ -29,6 +29,9 @@ Then there is the completely separate issue of whether: reordering over Memory **and the bytes inside regfile data** needs provided at the ISA Level. +This leaves a combinatorial explosion in the potential for confusion +in communication, leading to utter chaos. + Simple-V has made the decision that providing programmers with explicit control over the byte-ordering when data is transferred in and out of the register files is too great, and has chosen to require that, @@ -40,8 +43,10 @@ and it does **not** impact arithmetic operations. "Architecturally" is defined by Industry-standard convention to mean that how the Hardware is implemented is entirely down to the implementor, but that as far as *software* running on that hardware is concerned, -"Architecturally" everything appears as described. Mathematics would -describe any given implementation and an Architecturally +"Architecturally" everything appears - to programs - as described. +Mathematics would +describe a formal definition of any given implementation and an +Architecturally correctly-defined specification as Topologically "Homeomorphic". In other words once loaded, software may be written that -- 2.30.2