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"A later revision of IEEE 754 attempted to remedy this, but the formats it recommended were so inefficient that it has not found much acceptance. DEC64 is a bet
by macdice 7y ago
"A later revision of IEEE 754 attempted to remedy this, but the formats it recommended were so inefficient that it has not found much acceptance. DEC64 is a better alternative."
This is just plain wrong. The IEEE decimal float types are now in SQL as DECFLOAT, coming to C and C++, I could go on...
- acqq 7y ago> coming to C and C++ https://raw.githubusercontent.com/libdfp/libdfp/master/README.user https://raw.githubusercontent.com/libdfp/libdfp/master/READM... "libdfp The "Decimal Floating Point C Library" User's Guide for the GNU/Linux OS and GLIBC 2.10+ Contributed by IBM Corporation Copyright (C) 2010 - 2014 Free Software Foundation"
- RustyRussell 7y agoI know one of the authors who worked on this; he described it as "decimal floating" because he insisted "there's no point". Seems he was right: even IBM didn't do a hardware implementation after Power 6 IIRC.
- macdice 7y agoSeems useful to me. Fixed sized data is very convenient for computers (fits in a register, pass-by-value), and being able to represent 0.1 and 0.01 is very convenient for humans. The hardware does seem to be of questionable value; I heard rumours that the POWER hardware didn't actually beat the Intel software implementation running on an x86. That doesn't mean that the datatype is worthless. And it sure as hell doesn't mean that this DEC64 type, which has arbitrarily incompatible parameters but adds nothing, and is late to the game, is better!