Many small enhancements and bug fixes. Most notably, support for
the long long type has been added. So far only the "71-bit"
double-precision integer format supported in hardware is used,
but in the future 72 bits of precision may be an option.
There has been a slight change in the calling convention to make
code compiled with a frame pointer more easy to debug. Now the
frame pointer points to the word directly after the return
address, and that word contains the previously active frame
pointer. This means that both the return address and the previous
frame pointer is easily available. This version
has the changes.
Anders "ragge" Magnusson has contributed code to support the
The compiler now has two users.
version should be quite good, in case someone would like to give
it a try.
Testsuite failures: 260.
Testsuite failures: 353.
Testsuite failures: 1083.
Now assembling, linking, and executing in KLH10. The whole thing
took over 15 hours.
With the help of a maze of twisty little scripts connecting to a
PDP-10 through TELNET and FTP, the GCC testsuite can now assemble,
link, and run test cases in TOPS-20. These scripts will replace
the dummy scripts used earlier. A minimal C library has been
written to run the tests.
Testsuite failures are down to 25. Still using dummy
A list of patches submitted to the
Testsuite failures are down to 119. Still using dummy
Here is the result of
running the GCC testsuite. There's a summary at the end: 401
failures out of over 15000 test cases. However, due to a lack of
a full cross-development environment, the assembler, linker and
resulting executable are dummy scripts that always succeed.
Here is the result of
running a small testsuite to test GCC's generation of PDP-10
GCC implements most of the PDP-10 instruction set, as this comment from the machine
description file shows.
First program compiled with GCC and assembled with MACRO on a PDP-10.
Here's a proposed ABI.
The project has started.
An agreement has been signed to port the GNU C
compiler, assembler and debugger to PDP-10 and TOPS-20. The
project will start in January.
Selected versions of the GCC port can be downloaded
here. In general, later
versions are better, but not always.
There is a mailing list where I post weekly reports, and some
discussion about the port take place. To join the mailing list or
browse the message archive, click here.
You can also reach me at .
- kcc, originally Kok Chen's
PDP-10 C compiler, later rewritten by Ken Harrenstien.
Last changed May 2013, by lars