To: J3 07-332r1
From: Van Snyder (original from Dan Nagle and John Reid)
Subject: UTI 135 (p436): Internal contradiction about IEEE arithmetic
Date: 2007 November 13
References: J3/07-007r3, ISO/IEC TR 15580
1. Discussion
The editor points out a contradiction between the first and second
paragraphs of 14.9. The sentence in TR 15580 that corresponds to the
second paragraph of 14.9 is
"For each of the other arithmetic operators and for each implemented
IEEE rounding mode, the result shall be as specified in the IEEE
standard whenever the operands and IEEE result are normalized."
Here, "other" means other than divide. What is missing in 14.9 is
"and for each implemented IEEE rounding mode". We propose that this
be restored.
The editor is also critical of the words at the end of the second
paragraph of 14.9, which are unnecessary in view of 7.1.5.2.1. These
words were not present in TR 15580. We think that they should be
deleted.
2. Edits to 07-007r3
[436:16] After "but" insert "if the result of IEEE_SUPPORT_DATATYPE is
true for a particular real kind"
[436:17] Replace "normalized" by "normal"
[436:18-19] Replace list item by
" o For at least one rounding mode, the operations of addition,
subtraction and multiplication shall conform,"
[436:23] Delete the period, then add a new line "for that kind of real."
[436:24-26] In 14.9 IEEE arithmetic, replace the second paragraph by
"For each of the operations of addition, subtraction, and
multiplication, and for each implemented IEEE rounding mode,
the result shall be as specified in the IEEE International
Standard whenever the operands and IEEE result are normal."