[Bug middle-end/61577] [4.9.0 Regression] can't compile on hp-ux v3 ia64

["jvb at cyberscience dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61577

--- Comment #228 from John Buddery <jvb at cyberscience dot com> ---
Sorry it took a while, I've been away for a bit and have lots to catch up on.

These patches are for 11.1.0, but should work on earlier versions too. With
this I have a working gcc which I've tested on several large projects.

Most of the patch is a cumulation of the patches posted earlier in this thread
- unsigned pointer extension, reverting @gprel changes etc.

gcov-tool.c avoids build errors from ftwbuf differences on HP, apply if you hit
errors but may need tidying up.

ia64.md is the patch for long calls, to avoid the 25 bit limit which prevents
linking gcc. It's still a work in progress as the instruction bundling is
wrong, but it does work.

Note that you must apply the binutils patch (or build the current binutils
master, or a release after 2.36) to get an assembler that will work with brl
and the HP linker. Do not apply the ia64.md patch without building a patched
gnu assembler first!

Also note that you need a working C++ compiler to bootstrap. That sounds
obvious, but is harder than you think - as far as I  know, none of the
distributed g++ versions work sufficiently.

One way to get a working 4.9.2 g++ is described in my post in
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64919 but there may be other
solutions as well. I've never tried to bootstrap with aCC.

My configure command is:

../gcc-11.1.0/configure --enable-comdat --disable-libgomp --with
-as=/usr/local/binutils/bin/as --enable-languages=c,c++
--prefix=/usr/local/gcc-
11.1.0 --with-gmp=/usr/local_32 --with-mpc=/usr/local_32
--with-mpfr=/usr/local_
32 --with-dwarf2

The --enable-comdat I think is required. I think libgomp doesn't build, I've
never investigated though and disable it. I use dwarf2 as recent gdb versions
won't work. The assembler I use is a patched binutils 2.36.

Good luck!