C translator for calculator project

[ijabbott]

(06-06-2019 06:24 AM)Dan Wrote:  

(05-18-2019 10:30 AM)Dan Wrote:  Thanks Thomas for kindly offering to assist and for the information, you've inspired me to try again. I'll check out the Free42 source code and let you know how I go.

I gave up. Instead I've started writing my own IEEE quadruple routines. A big job, but one of the reasons I wanted to write my own calculator firmware was to learn about computer arithmetic, so I'm getting what I wished for!

I've finished multiplication, which is one of the easier routines. The most time consuming part was learning the ARM assembly instructions.

The weird thing about the Intel Decimal library is the huge tables repeated verbatim in various source files. Maybe that makes the code slightly faster, but it uses up a lot of precious space on a small, embedded system like a calculator.

It may be worth checking out the IBM's Decimal Floating Point C Library (libdfp), some of which is used by the WP-34S and WP-43S projects.