- now includes a table of all descriptors with coding scheme
(improves performance by 5% by allowing to avoid creation of
move-to-front sequences which will never be used)
- increased the size of markv_autogen.inc, clang doesn't seem
to have the long compilation time problem now
(probably was inadvertently fixed by using Huffman codec
serialization)
Includes:
- Multi-sequence move-to-front
- Coding by id descriptor
- Statistical coding of non-id words
- Joint coding of opcode and num_operands
Removed explicit form Huffman codec constructor
- The standard use case for it is to be constructed from initializer list.
Using serialization for Huffman codecs
Id descriptors are computed as a recursive hash of all instructions used
to define an id. Descriptors are invarint of actual id values and
the similar code in different files would produce the same descriptors.
Multiple ids can have the same descriptor. For example
%1 = OpConstant %u32 1
%2 = OpConstant %u32 1
would produce two ids with the same descriptor. But
%3 = OpConstant %s32 1
%4 = OpConstant %u32 2
would have descriptors different from %1 and %2.
Descriptors will be used as handles of move-to-front sequences in SPIR-V
compression.
Added data structure to SpirvStats which is used to collect statistics
on opcodes following other opcodes.
Added a simple analysis print-out to spirv-stats.
