Glide3 (for Linux) was originally written for x86 only but work has been done
and is ongoing to make it work on other platforms too:

Glide3 was not only written for Linux-x86 but also for dos,windows and mac.
The triangle setup code of the dos/windows/linux-x86 code is written in
x86-assembler. Luckily there are C-equivalents for those functions written
for the mac. These C-equivalents are enabled by defining GLIDE_USE_C_TRISETUP.

The x86-asm triangle setup code comes in multiple variants for different
x86-CPU's. Glide3 chooses runtime between these variants depending on the
CPU it is actually running on. The cpu detection (cpuid) code nescesarry for
this is also written in assembler. Recently this code has been wrapped with
#ifdef GL_X86.

The defining of GL_X86 or GLIDE_USE_C_TRISETUP is controleled by passing
USE_X86=1 to the makefile. Glide3 has been successfully tested on x86 without
USE_X86=1 passed to the makefile for the cvg h3 and h5 asics. IOW this has not
been tested for the sst1 and sst96 asics.

Even if compiled without GL_X86 defined and with GLIDE_USE_C_TRISETUP
defined the Glide3 code still contains a small piece of assembler: The
P6FENCE macro, this macro is used for io synchronisation and needs to be
defined for each platform you want to compile Glide3 on. You can find it in,
and to add a new platfrom need to add a define to:
cvg/init/sst1init.h
cvg/glide3/src/fxglide.h
h3/minihwc/minihwc.c
h3/minihwc/linhwc.c
h3/glide3/src/fxglide.h
h5/minihwc/minihwc.c
h5/minihwc/linhwc.c
h5/glide3/src/fxglide.h
sst1/init/initvg/sst1init.h
Currently for Linux there is a version of the P6FENCE macro for the following
platforms: x86, x86_64, ia64, alpha .

The original Glide3 code is not 64 bit clean, longs where used for 32 bits
registers, ptrs casted to and stored as ints, etc. RedHat has created and
tested a 64bit clean version of Glide3 for h5 and h3. This work has been
merged into current CVS, however this was based in an older Glide3 version,
so h5 and h3 might not be completely 64 bit clean. The other asics are far
from 64 bit clean. The Debian Glide3 package also contain some 64 bit
patches, these are probably equivalent to the RedHat ones, but might be
worth a look.

Last but not least some C-functions take the address of their first parameter
and assume this can be used as an array, iow they assume a certain stack
layout. Known functions doing this are:
cvg/glide3/src/gdraw.c:1142: _vptrisetup_cull
h5/glide3/src/gdraw.c:279: grDrawLine

64 bit todo:
-change use of long to int in texus2
-change use of long to FxX32 in register definitions of cvg, sst1, sst96
-actually compile it on a 64 bit platform and fix all warnings
-test, test, test