GeNN 4.8.1

Release Notes for GeNN v4.8.1

This release fixes a number of issues found in the 4.8.0 release and also includes some optimisation which could be very beneficial for some classes of model.

Bug fixes

1. Fixed bug relating to merging populations with variable references pointing to variables with different access duplication modes (#557).
2. Fixed infinite loop that could occur in code generator if a bracket was missed calling a GeNN function in a code snippet (#559).
3. Fixed bug that meant batched models which required previous spike times failed to compile (#565).
4. Fixed bug with DLL-searching logic on Windows which meant CUDA backend failed to load on some systems (#579).
5. Fixed a number of corner cases in the handling of VarAccessDuplication::SHARED_NEURON variables (#578).

Optimisations

1. When building models with large numbers of populations using the CUDA backend, compile times could be very large. This was at least in part due to over-verbose error handling code being generated. CodeGenerator::CUDA::Preferences::generateSimpleErrorHandling enables the generation of much more minimal error-handling code and can speed up compilation by up to 10x (#554).
2. Turned on multi-processor compilation option in Visual Studio solutions which speeds up compilation of GeNN by a significant amount (#555).
3. Fusing postsynaptic models was previously overly-conservative meaning large, highly-connected models using a postsynaptic model with additional state variables would perform poorly. These checks have been relaxed and brought into line with those used for fusing pre and postsynaptic updates coming from weight update models (#567).