From 1c8caccfe1bdbf0e83f6763f85b96ecbed3e1c85 Mon Sep 17 00:00:00 2001 From: Jacob Lifshay Date: Wed, 15 Mar 2023 20:15:25 -0700 Subject: [PATCH] fix inaccuracies in int_fp_mv.mdwn --- openpower/sv/int_fp_mv.mdwn | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/openpower/sv/int_fp_mv.mdwn b/openpower/sv/int_fp_mv.mdwn index 7e97e2c5a..1778e9400 100644 --- a/openpower/sv/int_fp_mv.mdwn +++ b/openpower/sv/int_fp_mv.mdwn @@ -432,21 +432,15 @@ operations.
-Different programming languages turn out to have completely different -semantics for FP to Integer conversion. Below is an overview +IEEE 754 doesn't specify what results are obtained when converting a NaN or out-of-range floating-point value to integer, so different programming languages and ISAs have made different choices. Below is an overview of the different variants, listing the languages and hardware that implements each variant. -**Standard IEEE754 conversion** - -This conversion is outlined in the IEEE754 specification. It is used -by nearly all programming languages and CPUs. In the case of OpenPOWER, -the rounding mode is read from FPSCR +For convenience, we will give those different conversion semantics names based on which common ISA or programming language uses them, since there may not be an established name for them: **Standard OpenPower conversion** -This conversion, instead of exact IEEE754 Compliance, performs -"saturation with NaN converted to minimum valid integer". This +This conversion performs "saturation with NaN converted to minimum valid integer". This is also exactly the same as the x86 ISA conversion semantics. OpenPOWER however has instructions for both: -- 2.30.2