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.
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'
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.
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.
Add --flatten-decorations to spirv-opt
Flattens decoration groups. That is, replace OpDecorationGroup
and its uses in OpGroupDecorate and OpGroupMemberDecorate with
ordinary OpDecorate and OpMemberDecorate instructions.
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/602
Exercises our public APIs more, and avoid including most
internal headers. It also shortens the processing part
of the code, but does make adding passes look more complex.
Doing this exposed issue 611, a bug in spvtools::Optimizer.
Autogenerating the following code:
- extension enum
- extension-to-string
- string-to-extension
- capability-to-string
Capability mapping table will not compile if incomplete.
TODO: Use "spirv-latest-version.h" instead of 1.1.
Added function to generate capability tables for tests.
The limit for the number of struct members is parameterized using
command line options.
Add --max-struct-depth command line option.
Add --max-switch-branches command line option.
Add --max-function-args command line option.
Add --max-control-flow-nesting-depth option.
Add --max-access-chain-indexes option.
Default-constructed Pass/PassManager will have a MessageConsumer
which ignores all messages. SetMessageConsumer() should be called
to supply a meaningful MessageConsumer.
De-duplicate constants and unifies the uses of constants for a SPIR-V
module. If two constants are defined exactly the same, only one of them
will be kept and all the uses of the removed constant will be redirected
to the kept one.
This pass handles normal constants (defined with
OpConstant{|True|False|Composite}), some spec constants (those defined
with OpSpecConstant{Op|Composite}) and null constants (defined with
OpConstantNull).
There are several cases not handled by this pass:
1) If there are decorations for the result id of a constant defining
instruction, that instruction will not be processed. This means the
instruction won't be used to replace other instructions and other
instructions won't be used to replace it either.
2) This pass does not unify null constants (defined with
OpConstantNull instruction) with their equivalent zero-valued normal
constants (defined with OpConstant{|False|Composite} with zero as the
operand values or component values).
For the spec constants defined by OpSpecConstantOp and
OpSpecContantComposite, if all of their operands are constants with
determined values (normal constants whose values are fixed), calculate
the correct values of the spec constants and re-define them as normal
constants.
In short, this pass replaces all the spec constants defined by
OpSpecContantOp and OpSpecConstantComposite with normal constants when
possible. So far not all valid operations of OpSpecConstantOp are
supported, we have several constriction here:
1) Only 32-bit integer and boolean (both scalar and vector) are
supported for any arithmetic operations. Integers in other width (like
64-bit) are not supported.
2) OpSConvert, OpFConvert, OpQuantizeToF16, and all the
operations under Kernel capability, are not supported.
3) OpCompositeInsert is not supported.
Note that this pass does not unify normal constants. This means it is
possible to have new generatd constants defining the same values.
This is experimental, and has not tests.
It's been used to debug validation of structured control flow.
- Has a legend describing special arcs to merge blocks and continue
targets.
- Labels the function entry block, with the Id of the function.
Add a pass to freeze spec constants to their default values. This pass does
not fold the frozen spec constants and does not handle SpecConstantOp
instructions and SpecConstantComposite instructions.
Add a high level version number for SPIRV-Tools, beginning
with v2016.0-dev. The README describes the format of the
version number.
The high level version number is extracted from the CHANGES
file. That works around:
- stale-bait for when we don't add tags to the repository
- our inability to add tags to the repository
Option --version causes spirv-as, spirv-dis, and spirv-val to
show the high level version number.
Add spvSoftwareVersionString to return the C-string for
the high level version number.
Add spvSoftwareVersionDetailsString() so that clients can get
more information if they want to.
Also allows us to clean up the uses in the tool executables files,
so now only one file includes build-version.inc.
Move the update-build-version logic to the only
CMakeLists file that needs it.
The update build version script takes a new argument
to name the output file.
Add test for named-barrier instructions and capability.
Add spv_target_env as an optional argument to CompileSuccessfully() and
CompileFailure(). Currently defaults to UNIVERSAL_1_0, though that
could change in the future.
Make spv_context a local variable in test methods instead of a
TextToBinaryTestBase member. Introduce ScopedContext to make temp
contexts easier.
For fulfilling this purpose, the |opcode| field in the
|spv_parsed_instruction_t| struct is changed to of type uint16_t.
Also add functions to query the information of a given SPIR-V
target environment.
Users always want to run all the checks. The spv_validate_options_t
mechanism, which provides little benefits to users, complicates the
internal implementation and also makes the tests exercise different
paths as users do.
Right now the tests are more like integration tests instead of
unit tests, which should be our next refactoring aim.
Now we have public headers arranged as follows:
$SPIRV_TOOLS_ROOT/include/spirv-tools/libspirv.h
$SPIRV_TOOLS_ROOT/include/spirv/spirv.h
$SPIRV_TOOLS_ROOT/include/spirv/GLSL.std.450.h
$SPIRV_TOOLS_ROOT/include/spirv/OpenCL.std.h
A project should use -I$SPIRV_TOOLS_ROOT/include
and then #include "spirv-tools/libspirv.h"
The headers from the SPIR-V Registry can be accessed as "spirv/spirv."
for example.
The install target should also install the headers from the SPIR-V
Registry. The libspirv.h header is broken otherwise.
The SPIRV-Tools library depends on the headers from the SPIR-V Registry.
The util/bitutils.h and util/hex_float.h are pulled into the internal
source tree. Those are not part of the public API to SPIRV-Tools.
Reorganize the README, and update its contents to more accurately
reflect the public release.
Remove the incremental "Changes" section.
Rename readme.md to README.md
Rename license.txt to LICENSE
Update the assembler tool to support -h, and make its help look
more consistent with the disassembler.
Change the target and library name to SPIRV-Tools. To better
match the GitHub repo name. Also, it's not SHOUTING.
Read from stdin if:
- no input filename specified
- the input filename is "-"
Also, output goes to stdout if the output filename (argument to -o)
is "-".
Previously the opcode table is declared as an global array and we
have spvOpcodeTableInitialize() modifying it. That can result in
race condition. Now spvOpcodeTabelGet() copies the whole underlying
array.
Replaced uint64_t with size_t in the places that make sense and
added spv_const_binary{,_t} to allow the interface to accept non
modifiable spirv where appropriate.
Note that we are more strict than Google style for one aspect:
pointer/reference indicators are adjacent to their types, not
their variables.
find . -name "*.h" -exec clang-format -i {} \;
find . -name "*.cpp" -exec clang-format -i {} \;
Previous the api used spv_text_t and spv_binary_t for both input
and output, but depending on the usage, you either MUST
call spvBinaryDestroy or you MUST NOT call spvBinaryDestroy on the
pointer.
