They take advantage of gcc's vector_size attribute and so only cross,
dot, qmul, qvmul and qrot (create rotation quaternion from two vectors)
are needed at this stage as basic (per-component) math is supported
natively by gcc.
The provided functions work on horizontal (array-of-structs) data, ie a
vec4d_t or vec4f_t represents a single vector, or traditional vector
layout. Vertical layout (struct-of-arrays) does not need any special
functions as the regular math can be used to operate on four vectors at
a time.
Functions are provided for loading a vec4 from a vec3 (4th element set
to 0) and storing a vec4 into a vec3 (discarding the 4th element).
With this, QF will require AVX2 support (needed for vec4d_t). Without
support for doubles, SSE is possible, but may not be worthwhile for
horizontal data.
Fused-multiply-add is NOT used because it alters the results between
unoptimized and optimized code, resulting in -mfma really meaning
-mfast-math-anyway. I really do not want to have to debug issues that
occur only in optimized code.
It is capable of parsing single expressions with fairly simple
operations. It current supports ints, enums, cvars and (external) data
structs. It is also thread-safe (in theory, needs proper testing) and
the memory it uses can be mass-freed.
This was inspired by
Hoard: A Scalable Memory Allocator
for Multithreaded Applications
Emery D. Berger, Kathryn S. McKinley, Robert D. Blumofe, Paul R.
Wilson,
It's not anywhere near the same implementation, but it did take a few
basic concepts. The idea is twofold:
1) A pool of memory from which blocks can be allocated and then freed
en-mass and is fairly efficient for small (4-16 byte) blocks
2) Tread safety for use with the Vulkan renderer (and any other
multi-threaded tasks).
However, based on the Hoard paper, small allocations are cache-line
aligned. On top of that, larger allocations are page aligned.
I suspect it would help qfvis somewhat if I ever get around to tweaking
qfvis to use cmem.
There's still some cleanup to do, but everything seems to be working
nicely: `make -j` works, `make distcheck` passes. There is probably
plenty of bitrot in the package directories (RPM, debian), though.
The vc project files have been removed since those versions are way out
of date and quakeforge is pretty much dependent on gcc now anyway.
Most of the old Makefile.am files are now Makemodule.am. This should
allow for new Makefile.am files that allow local building (to be added
on an as-needed bases). The current remaining Makefile.am files are for
standalone sub-projects.a
The installable bins are currently built in the top-level build
directory. This may change if the clutter gets to be too much.
While this does make a noticeable difference in build times, the main
reason for the switch was to take care of the growing dependency issues:
now it's possible to build tools for code generation (eg, using qfcc and
ruamoko programs for code-gen).
