Implementation of the simplification pass.
- Create pass that calls the instruction folder on each instruction and
propagate instructions that fold to a copy. This will do copy
propagation as well.
- Did not use the propagator engine because I want to modify the instruction
as we go along.
- Change folding to not allocate new instructions, but make changes in
place. This change had a big impact on compile time.
- Add simplification pass to the legalization passes in place of
insert-extract elimination.
- Added test cases for new folding rules.
- Added tests for the simplification pass
- Added a method to the CFG to apply a function to the basic blocks in
reverse post order.
Contributes to #1164.
Add pkg-config file for shared libraries
Properly build SPIRV-Tools DLL
Test C interface with shared library
Set PATH to shared library file for c_interface_shared test
Otherwise, the test won't find SPIRV-Tools-shared.dll.
Do not use private functions when testing with shared library
Make all symbols hidden by default for shared library target
* Added TypeManager::RebuildType
* rebuilds the type and its constituent types in terms of memory owned
by the manager.
* Used by TypeManager::RegisterType to properly allocate memory
* Adding an unit test to expose the issue
* Added some tests to provide coverage of RebuildType
* Added an accessor to the target pointer for a forward pointer
Create the folding engine that will
1) attempt to fold an instruction.
2) iterates on the folding so small folding rules can be easily combined.
3) insert new instructions when needed.
I've added the minimum number of rules needed to test the features above.
This patch adds LoopUtils class to handle some loop related transformations. For now it has 2 transformations that simplifies other transformations such as loop unroll or unswitch:
- Dedicate exit blocks: this ensure that all exit basic block
(out-of-loop basic blocks that have a predecessor in the loop)
have all their predecessors in the loop;
- Loop Closed SSA (LCSSA): this ensure that all definitions in a loop are used inside the loop
or in a phi instruction in an exit basic block.
It also adds the following capabilities:
- Loop::IsLCSSA to test if the loop is in a LCSSA form
- Loop::GetOrCreatePreHeaderBlock that can build a loop preheader if required;
- New methods to allow on the fly updates of the loop descriptors.
- New methods to allow on the fly updates of the CFG analysis.
- Instruction::SetOperand to allow expression of the index relative to Instruction::NumOperands (to be compatible with the index returned by DefUseManager::ForEachUse)
Creates a pass that will remove instructions that are invalid for the
current shader stage. For the instruction to be considered for replacement
1) The opcode must be valid for a shader modules.
2) The opcode must be invalid for the current shader stage.
3) All entry points to the module must be for the same shader stage.
4) The function containing the instruction must be reachable from an entry point.
Fixes#1247.
* Had to remove templating from InstructionBuilder as a result
* now preserved analyses are specified as a constructor argument
* updated tests and uses
* changed static_assert to a runtime assert
* this should probably get further changes in the future
* When handling unreachable merges and continues, do not optimize to the
same IR
* pass did not check whether the unreachable blocks were in the
optimized form before transforming them
* added a test to catch this issue
* Should handle all possibilities
* Stricter checks for what is disallowed:
* header and header
* merge and merge
* Allow header and merge blocks to be merged
* Erases the structured control declaration if merging header and
merge blocks together.
* If the dead branch elim is performed on a module without structured
control flow, the OpSelectionMerge may not be present
* Add a check for pointer validity before dereferencing
* Added a test to catch the bug
* Forces traversal of phis if the def has changed to varying
* Mark a phi as varying if all incoming values are varying
* added a test to catch the bug
This adds Dead Insert Elimination to the end of the
--eliminate-insert-extract pass. See the new tests for examples of code
that will benefit.
Essentially, this removes OpCompositeInsert instructions which are not
used, either because there is no instruction which uses the value at the
index it is inserted, or because a subsequent insert intercepts any such
use.
This code has been seen to remove significant amounts of dead code from
real-life HLSL shaders being ported to Vulkan. In fact, it is needed to
remove dead texture samples which cause Vulkan validation layer errors
(unbound textures and samplers) if not removed . Such DCE is thus
required for fxc equivalence and legalization.
This analysis operates across "chains" of Inserts which can also contain
Phi instructions.
* Handles simple cases only
* Identifies phis in blocks with two predecessors and attempts to
convert the phi to an select
* does not perform code motion currently so the converted values must
dominate the join point (e.g. can't be defined in the branches)
* limited for now to two predecessors, but can be extended to handle
more cases
* Adding if conversion to -O and -Os
Ban floating point case for OpAtomicLoad, OpAtomicExchange,
OpAtomicCompareExchange. In graphics (Shader) environments, these
instructions only operate on scalar integers. Ban the floating point
case. OpenCL supports atomic_float.
Implemented Vulkan-specific rules:
- OpTypeImage must declare a scalar 32-bit float or 32-bit integer type
for the “Sampled Type”.
- OpSampledImage must only consume an “Image” operand whose type has its
“Sampled” operand set to 1.
The current folding routines have a very cumbersome interface, make them
harder to use, and not a obvious how to extend.
This change is to create a new interface for the folding routines, and
show how it can be used by calling it from CCP.
This does not make a significant change to the behaviour of CCP. In
general it should produce the same code as before; however it is
possible that an instruction that takes 32-bit integers as inputs and
the result is not a 32-bit integer or bool will not be folded as before.
It seems like andriod has a problem with INT32_MAX and the like. I'll
explicitly define those if the are not already defined.
The class factorize the instruction building process.
Def-use manager analysis can be updated on the fly to maintain coherency.
To be updated to take into account more analysis.
* AddToWorklist can now be called unconditionally
* It will only add instructions that have not already been marked as
live
* Fixes a case where a merge was not added to the worklist because the
branch was already marked as live
* Added two similar tests that fail without the fix
We have come across a driver bug where and OpUnreachable inside a loop
is causing the shader to go into an infinite loop. This commit will try
to avoid this bug by turning OpUnreachable instructions that are
contained in a loop into branches to the loop merge block.
This is not added to "-O" and "-Os" because it should only be used if
the driver being targeted has this problem.
Fixes#1209.
At the moment specialization constants look like constants to ccp. This
causes a problem because they are handled differently by the constant
manager.
I choose to simply skip over them, and not try to add them to the value
table. We can do specialization before ccp if we want to be able to
propagate these values.
Fixes#1199.
The current code expects the users of the constant manager to initialize
it with all of the constants in the module. The problem is that you do
not want to redo the work multiple times. So I decided to move that
code to the constructor of the constant manager. This way it will
always be initialized on first use.
I also removed an assert that expects all constant instructions to be
successfully mapped. This is because not all OpConstant* instruction
can map to a constant, and neither do the OpSpecConstant* instructions.
The real problem is that an OpConstantComposite can contain a member
that is OpUndef. I tried to treat OpUndef like OpConstantNull, but this
failed because an OpSpecConstantComposite with an OpUndef cannot be
changed to an OpConstantComposite. Since I feel this case will not be
common, I decided to not complicate the code.
Fixes#1193.
* Added for Instruction, BasicBlock, Function and Module
* Uses new disassembly functionality that can disassemble individual
instructions
* For debug use only (no caching is done)
* Each output converts module to binary, parses and outputs an
individual instruction
* Added a test for whole module output
* Disabling Microsoft checked iterator warnings
* Updated check_copyright.py to accept 2018
* Changed MemPass::InsertPhiInstructions to set basic blocks for new
phis
* Local SSA elim now maintains instr to block mapping
* Added a test and confirmed it fails without the updated phis
* IRContext::set_instr_block no longer builds the map if the analysis is
invalid
* Added instruction to block mapping verification to
IRContext::IsConsistent()
This improves Extract replacement to continue through VectorShuffle.
It will also handle Mix with 0.0 or 1.0 in the a-value of the desired
component.
To facilitate optimization of VectorShuffle, the algorithm was refactored
to pass around the indices of the extract in a vector rather than pass the
extract instruction itself. This allows the indices to be modified as the
algorithm progresses.
Modified ADCE to remove dead globals.
* Entry point and execution mode instructions are marked as alive
* Reachable functions and their parameters are marked as alive
* Instruction deletion now deferred until the end of the pass
* Eliminated dead insts set, added IsDead to calculate that value
instead
* Ported applicable dead variable elimination tests
* Ported dead constant elim tests
Added dead function elimination to ADCE
* ported dead function elim tests
Added handling of decoration groups in ADCE
* Uses a custom sorter to traverse decorations in a specific order
* Simplifies necessary checks
Updated -O and -Os pass lists.
Pass now paints live blocks and fixes constant branches and switches as
it goes. No longer requires structured control flow. It also removes
unreachable blocks as a side effect. It fixes the IR (phis) before doing
any code removal (other than terminator changes).
Added several unit tests for updated/new functionality.
Does not remove dead edge from a phi node:
* Checks that incoming edges are live in order to retain them
* Added BasicBlock::IsSuccessor
* added test
Fixing phi updates in the presence of extra backedge blocks
* Added tests to catch bug
Reworked how phis are updated
* Instead of creating a new Phi and RAUW'ing the old phi with it, I now
replace the phi operands, but maintain the def/use manager correctly.
For unreachable merge:
* When considering unreachable continue blocks the code now properly
checks whether the incoming edge will continue to be live.
Major refactoring for review
* Broke into 4 major functions
* marking live blocks
* marking structured targets
* fixing phis
* deleting blocks
This fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/1143.
When an instruction transitions from constant to bottom (varying) in the
lattice, we were telling the propagator that the instruction was
varying, but never updating the actual value in the values table.
This led to incorrect value substitutions at the end of propagation.
The patch also re-enables CCP in -O and -Os.
In HLSL structured buffer legalization, pointer to pointer types
are emitted to indicate a structured buffer variable should be
treated as an alias of some other variable. We need an option to
relax the check of pointer types in logical addressing mode to
catch other validation errors.
Add post-order tree iterator.
Add DominatorTreeNode extensions:
- Add begin/end methods to do pre-order and post-order tree traversal from a given DominatorTreeNode
Add DominatorTree extensions:
- Add begin/end methods to do pre-order and post-order tree traversal
- Tree traversal ignore by default the pseudo entry block
- Retrieve a DominatorTreeNode from a basic block
Add loop descriptor:
- Add a LoopDescriptor class to register all loops in a given function.
- Add a Loop class to describe a loop:
- Loop parent
- Nested loops
- Loop depth
- Loop header, merge, continue and preheader
- Basic blocks that belong to the loop
Correct a bug that forced dominator tree to be constantly rebuilt.
Turn `Linker::Link()` into free functions
As very little information was kept in the Linker class, we can get rid
of the whole class and have the `Link()` as free functions instead; the
environment target as well as the consumer are passed along through an
`spv_context` object.
The resulting linked_binary is passed as a pointer rather than a
reference to follow the Google C++ Style guidelines.
Addresses remaining comments from
https://github.com/KhronosGroup/SPIRV-Tools/pull/693 about the SPIR-V
linker.
Fix variable naming in the linker
Some of the variables were using mixed case, which did not follow the
Google C++ Style guidelines.
Linker: Use EXPECT_EQ when possible and update some test
* Replace occurrences of ASSERT_EQ by EXPECT_EQ when possible;
* Reformulated some of the error messages;
* Added the symbol name in the error message when there is a type or
decoration mismatch between the imported and exported declarations.
Opt: List all duplicates removed by RemoveDuplicatePass in the header
Opt: Make the const version of GetLabelInst() return a pointer
For consistency with the non-const version, as well as other similar
functions.
Opt: Rename function_end to EndInst()
As pointed out by dneto0 the previous name was quite confusing and could
be mistaken with a function returning an end iterator.
Also change the return type of the const version to a pointer rather
than a reference, for consistency.
Opt: Add performance comment to RemoveDuplicateTypes and decorations
This comment was requested during the review of
https://github.com/KhronosGroup/SPIRV-Tools/pull/693.
Opt: Add comments and fix variable naming in RemoveDuplicatePass
* Add missing comments to private functions;
* Rename variables that were using mixed case;
* Add TODO for moving AreTypesEqual out.
Linker: Remove commented out code and add TODOs
Linker: Merged together strings that were too much splitted
Implement a C++ RAII wrapper around spv_context
In value numbering, we treat loads and stores of images, ie OpImageLoad,
as a memory operation where it is interested in the "base address" of
the instruction. In those cases, it is an image instruction.
The problem is that `Instruction::GetBaseAddress()` does not account for
the image instructions, so the assert at the end to make sure it found
a valid base address for its addressing mode fails.
The solution is to look at the load/store instruction to determine how
the assertion should be done.
Fixes#1160.
This fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/1159. I
had missed a nuance in the original algorithm. When simulating Phi
instructions, the SSA edges out of a Phi instruction should never be
added to the list of edges to simulate.
Phi instructions can be in SSA def-use cycles with other Phi
instructions. This was causing the propagator to fall into an infinite
loop when the same def-use edge kept being added to the queue.
The original algorithm in the paper specifically separates the visit of
a Phi instruction vs the visit of a regular instruction. This fix makes
the implementation match the original algorithm.
