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
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.
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.
If the variable_pointer extension is used:
* OpLoad's pointer argument may be the result of any of the following:
* OpSelect
* OpPhi
* OpFunctionCall
* OpPtrAccessChain
* OpCopyObject
* OpLoad
* OpConstantNull
* Return value of a function may be a pointer.
* It is valid to use a pointer as the return value of a function.
* OpStore should allow a variable pointer argument.
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
The spvtools::Optimizer::Run method should also write the output binary
if optimization succeeds without changes but the output binary vector
does not have exactly the same contents as the input binary.
We have to check both the base pointer of the storage and the size of
the vector
Added a test for this too.
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/611
Supported in assembler, disassembler, and binary parser.
The validator does not check SPV_AMD_gcn_shader validation rules
beyond parsing the extension.
Adds generic support for generating instruction tables for vendor
extensions.
Adds generic support for extensions the validator should recognize
(but not check) but which aren't derived from the SPIR-V core
grammar file.
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/594
The SPIR-V core grammar file in a recent SPIRV-Headers
applied the fix from Rev 7 of SPV_KHR_16bit_storage:
FPRoundingMode enums are now enabled by the capabilities
introduced by that extension.
Update the SPIRV-Tools tests accordingly.
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.
Known extensions are saved in validation state. Unknown extension
produce a dignostic message, but do not fail the validation.
Moved extension definitions to their own file.
The assembler assigns ID numbers sequentially, so it's confusing
to have a %1 in the source assembly when it isn't the first mentioned
ID. Rewrite the ID names to avoid this situation in a few cases.
From the SPIR-V Spec 2.16.1:
A function declaration (an OpFunction with no basic blocks), must have
a Linkage Attributes Decoration with the Import Linkage Type.
A function definition (an OpFunction with basic blocks) cannot be
decorated with the Import Linkage Type.
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.
If a merge block is reachable, then it must be *strictly* dominated
by its header. Until now we've allowed the header and the merge
block to be the same.
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/551
Also: Use dominates and postdominates methods on BasicBlock to
improve readability.
It is best to check the error messages of unit tests that fail
validation. This will ensure that a validation failure is due to what we
expect and not due to some secondary reason.
Updating SPIR-V Validator unit tests with error message checks.
When applied to a structure-type member, all members of that structure
type must also be decorated with BuiltIn. (No allowed mixing of built-in
variables and non-built-in variables within a single structure.)
When applied to a structure-type member, that structure type cannot be
contained as a member of another structure type.
There is at most one object per Storage Class that can contain a
structure type containing members decorated with BuiltIn, consumed per
entry-point.
It is acceptable for OpAccessChain, OpInBoundsAccessChain,
OpPtrAccessChain, OpInBoundsPtrAccessChain, OpCompositeInsert, and
OpCompositeExtract to not take any indexes as arguments. In such cases,
no indexing will be done on the Base pointer/composite.
Added a new file where all the decoration validation can be performed.
In this change the SPIRV Spec Section 2.16.1 is implemented:
"It is illegal to initialize an imported variable. This means
that a module-scope OpVariable with initialization value cannot be
marked with the Import Linkage Type."
Also added unit tests.
* Added the decoration class as well as the code that registers the
decorations for each <id> and also decorations for struct members.
* Added unit tests for decorations in ValidationState as well as
decoration id tests.
According to the SPIRV Spec (2.16.1):
* There is at least one OpEntryPoint instruction, unless the Linkage
capability is being used.
* No function can be targeted by both an OpEntryPoint instruction and an
OpFunctionCall instruction.
Also updated unit tests to includ OpEntryPoint.
We are adding a new API which can be called to run the SPIR-V validator,
and retrieve the ValidationState_t object. This is very useful for
unit testing.
I have also added basic unit tests that demonstrate usage of this flow
and ease of use to verify correctness.
The validity of each command is checked based on the descripton in
SPIR-V Spec Section 3.32.12 (Composite Instructions).
Also checked that the number of indexes passed to these commands does
not exceed the limit described in 2.17 (Universal Limits).
Also added unit tests for each one.
entry_block_to_construct_ maps an entry block to its construct. The key
in this map (the entry block) is not unique, and therefore the entry for
the continue construct gets overwritten when the selection construct is
discovered.
Since a given block may be the entry block of different types of
constructs, the (basic_block, construct_type) pair should be able to
uniquely identify the construct.
Adds test:
- In this test, a basic block is the entry block of a continue construct
as well as the entry block of a selection construct.
It can be shown that this unit test would crash without the fix in this
PR and passes with the fix in this PR.
Validation for OpPtrAccessChain is similar to OpAccessChain with the
following difference: OpPtrAccessChain takes an extra argument (word 4)
which is the Element <id> argument.
Validation for OpInBoundsPtrAccessChain is also similar to OpPtrAccessChain.
Also added tests for all access chain instructions:
Modified the existing parameterized tests to accommodate OpPtrAccessChain and
OpInBoundsPtrAccessChain.
Also fixed a typo in previous commits.
Using parameterized unit tests to avoid duplicate code that runs the
tests of OpAccessChain and OpInBoundsAccessChain.
This is also a steppingstone to adding tests for OpPtrAccessChain and
OpInBoundsPtrAccessChain.
According to Section 2.17 (Universal Limits) of the SPIR-V Spec, the
control flow nesting depth may not be larger than 1023.
This is checked only when we are required to have structured
control flow. Otherwise it's not clear how to compute control
flow nesting depth.
- Parse CHANGES file with Universal Python line endings in case
the source tree was checked out with Windows line endings.
- Use our own clone of strnlen_s which might not be available
everywhere.
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/508
According to sectin 2.17 in SPIR-V Spec, the structure nesting depth may
not be larger than 255. This is interpreted as structures nested in
structures. The code does not look into arrays or follow pointers to see
if it reaches a structure downstream.
Use memoization to avoid exponential runtime.
The validation code for OpAccessChain was missing OpTypeRuntimeArray as
a possible type that can be indexed into.
This was caught by running the validator on VKCTS.
Also adding unit tests for it.
* Result Type must be an OpTypePointer. Its Type operand must be the
type reached by walking the Base’s type hierarchy down to the last
provided index in Indexes, and its Storage Class operand must be the
same as the Storage Class of Base.
* Base must be a pointer, pointing to the base of a composite object.
* Indexes walk the type hierarchy to the desired depth, potentially down
to scalar granularity. The first index in Indexes will select the
top-level member/element/component/element of the base composite. All
composite constituents use zero-based numbering, as described by their
OpType... instruction. The second index will apply similarly to that
result, and so on. Once any non-composite type is reached, there must
be no remaining (unused) indexes. Each of the Indexes must:
- be a scalar integer type,
- be an OpConstant when indexing into a structure.
* Check for the case where no indexes are passed to OpAccessChain.
Minor improvements based on code review.
According to the Universal Limits section of the SPIR-V Spec (2.17), the
number of global variables may not exceed 65,535 and the number of local
variables may not exceed 524,287.
Also added unit tests for each one.
According to the SPIR-V spec (section 2.17: Universal Limits), the
OpTypeFunction instruction may not take more than 255 arguments for the
function. Also added unit tests for it.
The number of (literal, label) pairs passed to OpSwitch may not exceed
16,383. Added code to validate this and added unit tests for it.
Also fixed a typo in another validor error message.
This is described in Section 2.17 of the SPIR-V Spec.
* Updated existing unit test 'SemanticsIdIsAnIdNotALiteral' to pass by
manipulating the ID bound in its binary header.
* Fixed boundary check in the code.
* Added unit test to check the case that the largest ID is equal to the
ID bound.
This change implements the validation for usages of OpSampledImage
instruction as described in the Data Rules section of the Universal
Validation Rules of the SPIR-V Spec.
SpecConstantComposite may specialize to a vector, matrix, array, or
struct. In each case, the number of components and type of components
that are being specialized to must match the expected result type.
Removed use of macros in these tests.
Now using the spvValidateBase class. Using CompileSuccessfully(), and
ValidateInstructions() to compile to binary and run the validator. Also
using getDiagnosticString() to check the proper error message string.
All the heavy lifting is done in ValidateBase class.
According to the Data Rules section of 2.16.1. Universal Validation
Rules of the SPIR-V Spec:
Forward reference operands in an OpTypeStruct
* must be later declared with OpTypePointer
* the type pointed to must be an OpTypeStruct
* had an earlier OpTypeForwardPointer forward reference to the same <id>
