From 924bad992a24ee81a5364fb0b974c003b43a501e Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Sat, 15 Apr 2023 10:43:40 +0100 Subject: [PATCH] clarify notation on _RT in ls008 --- openpower/sv/rfc/ls008.mdwn | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/openpower/sv/rfc/ls008.mdwn b/openpower/sv/rfc/ls008.mdwn index 03a9c1290..252270c5d 100644 --- a/openpower/sv/rfc/ls008.mdwn +++ b/openpower/sv/rfc/ls008.mdwn @@ -98,13 +98,12 @@ Add the following entries to: # Notation, Section 1.3.2 -When register operands (`RA, RT, BF`) are prefixed by a single underscore -(`_RT, _RA, _BF`) the variable contains the contents of the instruction field -not the contents of the Register File referenced *by* that field. Example: -`_RT` contains the contents of bits 5 thru 10. The relationship -`RT = GPR(_RT)` is thus always true. Uses include making alternative -decisions within an instruction based on whether the operand field -is zero or non-zero. +When destination register operands (`RT, RS`) are prefixed by a single +underscore (`_RT, _RS`) the variable also contains the contents of the +instruction field. +This avoids confusion in pseudocode when a destination register is +assigned (`RT <- x`) but earlier it was the operand bits that were +checked (`if RT = 0`) ---------------- -- 2.30.2