Create aggressive dead code elimination pass
This pass eliminates unused code from functions. In addition,
it detects and eliminates code which may have spurious uses but which do
not contribute to the output of the function. The most common cause of
such code sequences is summations in loops whose result is no longer used
due to dead code elimination. This optimization has additional compile
time cost over standard dead code elimination.
This pass only processes entry point functions. It also only processes
shaders with logical addressing. It currently will not process functions
with function calls. It currently only supports the GLSL.std.450 extended
instruction set. It currently does not support any extensions.
This pass will be made more effective by first running passes that remove
dead control flow and inlines function calls.
This pass can be especially useful after running Local Access Chain
Conversion, which tends to cause cycles of dead code to be left after
Store/Load elimination passes are completed. These cycles cannot be
eliminated with standard dead code elimination.
Additionally: This transform uses a whitelist of instructions that it
knows do have side effects, (a.k.a. combinators). It assumes other
instructions have side effects: it will not remove them, and assumes
they have side effects via their ID operands.
A SSA local variable load/store elimination pass.
For every entry point function, eliminate all loads and stores of function
scope variables only referenced with non-access-chain loads and stores.
Eliminate the variables as well.
The presence of access chain references and function calls can inhibit
the above optimization.
Only shader modules with logical addressing are currently processed.
Currently modules with any extensions enabled are not processed. This
is left for future work.
This pass is most effective if preceeded by Inlining and
LocalAccessChainConvert. LocalSingleStoreElim and LocalSingleBlockElim
will reduce the work that this pass has to do.
Fixes Instruction::ForEachInId so it covers
SPV_OPERAND_TYPE_MEMORY_SEMANTICS_ID and SPV_OPERAND_TYPE_SCOPE_ID.
Future proof a bit by using the common spvIsIdType routine.
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/697
If this is used as a static library in another project, this does not
need to be installed, and otherwise will just clutter the application's install.
To use, define SKIP_SPIRV_TOOLS_INSTALL which internally defines
ENABLE_SPIRV_TOOLS_INSTALL to control installation.
Also include GNUInstallDirs to get standard output 'lib' directory which is sometimes 'lib64' and not 'lib'
Fixed width encoding is intended to be used for small unsigned integers
when the upper bound is known both to the encoder and the decoder
(for example move-to-front rank).
Command line application is located at tools/spirv-markv
API at include/spirv-tools/markv.h
At the moment only very basic compression is implemented, mostly varint.
Scope of supported SPIR-V opcodes is also limited.
Using a simple move-to-front implementation instead of encoding mapped
ids.
Work in progress:
- Does not cover all of SPIR-V
- Does not promise compatibility of compression/decompression across
different versions of the code.
The implementation is based on AVL and order statistic tree.
It accepts all kinds of values and the implementation
doesn't expect the behaviour to be consistent with id coding.
Intended by SPIR-V compression algorithms.
This gives us shorter testing time since we can use the container
based testing environment, which starts faster. Also using make
means we don't need to install ninja separately.
Create class to encapsulate control flow analysis and share across
validator and optimizer. A WIP. Start with DepthFirstTraversal. Next
pull in CalculateDominators.
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.
