- Replace ostringstream with custom implementation.
~30% performance uplift on vector-shuffle-oom test.
Allocations are measurably reduced in Valgrind.
- Replace std::vector with SmallVector.
Classic malloc optimization, small vectors are backed by inline data.
~ 7-8% gain on vector-shuffle-oom on GCC 8 on Linux.
- Use an object pool for IVariant type.
We generally allocate a lot of SPIR* objects. We can amortize these
allocations neatly by pooling them.
- ~15% overall uplift on ./test_shaders.py --iterations 10000 shaders/.
This is a pragmatic trick to avoid symbol collision where a project
links against SPIRV-Cross statically, while linking to other projects
which also use SPIRV-Cross statically. We can end up with very awkward
symbol collisions which can resolve themselves silently because
SPIRV-Cross is pulled in as necessary. To fix this, we must use
different symbols and embed two copies of SPIRV-Cross in this scenario,
now with different namespaces, which in turn leads to different symbols.
