* Improve algorithm to reorder blocks in a function
In dead branch elimination, blocks can end up in a the wrong order, so
there is code to reorder the blocks in structured order. The problem is
that the algorithm to do that is very poor. It involves many searchs in
the function for the correct position to place the block, as well as
moving many block in the vector.
The solution is to write a specialized function in the function class
that will reorder the blocks in structured order. After computing the
structured order, reordering the block can be done in linear time, with
very little overhead.
* No longer blindly add global non-semantic info instructions to global
types and values
* functions now have a list of non-semantic instructions that succeed
them in the global scope
* global non-semantic instructions go in global types and values if
they appear before any function, otherwise they are attached to the
immediate function predecessor in the module
* changed ADCE to use the function removal utility
* Modified EliminateFunction to have special handling for non-semantic
instructions in the global scope
* non-semantic instructions are moved to an earlier function (or full
global set) if the function they are attached to is eliminated
* Added IRContext::KillNonSemanticInfo to remove the tree of
non-semantic instructions that use an instruction
* this is used in function elimination
* There is still significant work in the optimizer to handle
non-semantic instructions fully in the optimizer
Handles the OpenCL100Debug extension in inlining. It preserves the information that is available while also adding the debug inlined at for all of the inlining that it does.
* Preserve debug info in eliminate-dead-functions
The elimination of dead functions makes OpFunction operand of
DebugFunction invalid. This commit replaces the operand with
DebugInfoNone.
When DebugScope is given in SPIR-V, each instruction following the
DebugScope is from the lexical scope pointed by the DebugScope in
the high level language. We add DebugScope struction to keep the
scope information in Instruction class. When ir_loader loads
DebugScope/DebugNoScope, it keeps the scope information in
|last_dbg_scope_| and lets following instructions have that scope
information.
In terms of DebugDeclare/DebugValue, if it is in a function body
but outside of a basic block, we keep it in |debug_insts_in_header_|
of Function class. If it is in a basic block, we keep it as a normal
instruction i.e., in a instruction list of BasicBlock.
* Move ProcessFunction* function from pass to the context.
There are a few functions that are used to traverse the call tree.
They currently live in the Pass class, but they have nothing to do with
a pass, and may be needed outside of a pass. They would be better in
the ir context, or in a specific call tree class if we ever have a need
for it.
* Don't inline recursive functions.
Inlining does not check if a function is recursive or not. This has
been fine as long as the shader was a Vulkan shader, which forbid
recursive functions. However, not all shaders are vulkan, so either
we limit inlining to Vulkan shaders or we teach it to look for recursive
functions.
I prefer to keep the passes as general as is reasonable. The change
does not require much new code in inlining and gives a reason to refactor
some other code.
The changes are to add a member function to the Function class that
checks if that function is recursive or not.
Then this is used in inlining to not inlining a function call if it calls
a recursive function.
* Add id to function analysis
There are a few places that build a map from ids to Function whose
result is that id. I decided to add an analysis to the context for this
to reduce that code, and simplify some of the functions.
* Add missing file.
These are bookend passes designed to help preserve line information
across passes which delete, move and clone instructions. The propagation
pass attaches a debug line instruction to every instruction based on
SPIR-V line propagation rules. It should be performed before optimization.
The redundant line elimination pass eliminates all line instructions
which match the previous line instruction. This pass should be performed
at the end of optimization to reduce physical SPIR-V file size.
Fixes#2027.
When using lldb and/or gdb I frequently get odd std::string failures
when using the IR printing instructions we have now. This adds the
methods Instruction::Dump(), BasicBlock::Dump() and Function::Dump() to
emit the output of the pretty print to stderr.
With this I can now reliably print IR from gdb and lldb sessions.
This CL moves the files in opt/ to consistenly be under the opt::
namespace. This frees up the ir:: namespace so it can be used to make a
shared ir represenation.
This pass replaces the load/store elimination passes. It implements the
SSA re-writing algorithm proposed in
Simple and Efficient Construction of Static Single Assignment Form.
Braun M., Buchwald S., Hack S., Leißa R., Mallon C., Zwinkau A. (2013)
In: Jhala R., De Bosschere K. (eds)
Compiler Construction. CC 2013.
Lecture Notes in Computer Science, vol 7791.
Springer, Berlin, Heidelberg
https://link.springer.com/chapter/10.1007/978-3-642-37051-9_6
In contrast to common eager algorithms based on dominance and dominance
frontier information, this algorithm works backwards from load operations.
When a target variable is loaded, it queries the variable's reaching
definition. If the reaching definition is unknown at the current location,
it searches backwards in the CFG, inserting Phi instructions at join points
in the CFG along the way until it finds the desired store instruction.
The algorithm avoids repeated lookups using memoization.
For reducible CFGs, which are a superset of the structured CFGs in SPIRV,
this algorithm is proven to produce minimal SSA. That is, it inserts the
minimal number of Phi instructions required to ensure the SSA property, but
some Phi instructions may be dead
(https://en.wikipedia.org/wiki/Static_single_assignment_form).
We are seeing shaders that have multiple returns in a functions. These
functions must get inlined for legalization purposes; however, the
inliner does not know how to inline functions that have multiple
returns.
The solution we will go with it to improve the merge return pass to
handle structured control flow.
Note that the merge return pass will assume the cfg has been cleanedup
by dead branch elimination.
Fixes#857.
* 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
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
Re-formatted the source tree with the command:
$ /usr/bin/clang-format -style=file -i \
$(find include source tools test utils -name '*.cpp' -or -name '*.h')
This required a fix to source/val/decoration.h. It was not including
spirv.h, which broke builds when the #include headers were re-ordered by
clang-format.
Each instruction is given an unique id that can be used for ordering
purposes. The ids are generated via the IRContext.
Major changes:
* Instructions now contain a uint32_t for unique id and a cached context
pointer
* Most constructors have been modified to take a context as input
* unfortunately I cannot remove the default and copy constructors, but
developers should avoid these
* Added accessors to parents of basic block and function
* Removed the copy constructors for BasicBlock and Function and replaced
them with Clone functions
* Reworked BuildModule to return an IRContext owning the built module
* Since all instructions require a context, the context now becomes the
basic unit for IR
* Added a constructor to context to create an owned module internally
* Replaced uses of Instruction's copy constructor with Clone whereever I
found them
* Reworked the linker functionality to perform clones into a different
context instead of moves
* Updated many tests to be consistent with the above changes
* Still need to add new tests to cover added functionality
* Added comparison operators to Instruction
* Added an internal option to LinkerOptions to verify merged ids are
unique
* Added a test for the linker to verify merged ids are unique
* Updated MergeReturnPass to supply a context
* Updated DecorationManager to supply a context for cloned decorations
* Reworked several portions of the def use tests in anticipation of next
set of changes
Add extra iterators for ir::Module's sections
Add extra getters to ir::Function
Add a const version of BasicBlock::GetLabelInst()
Use the max of all inputs' version as version
Split debug in debug1 and debug2
- Debug1 instructions have to be placed before debug2 instructions.
Error out if different addressing or memory models are found
Exit early if no binaries were given
Error out if entry points are redeclared
Implement copy ctors for Function and BasicBlock
- Visual Studio ends up generating copy constructors that call deleted
functions while compiling the linker code, while GCC and clang do not.
So explicitly write those functions to avoid Visual Studio messing up.
Move removing duplicate capabilities to its own pass
Add functions running on all IDs present in an instruction
Remove duplicate SpvOpExtInstImport
Give default options value for link functions
Remove linkage capability if not making a library
Check types before allowing to link
Detect if two types/variables/functions have different decorations
Remove decorations of imported variables/functions and their types
Add a DecorationManager
Add a method for removing all decorations of id
Add methods for removing operands from instructions
Error out if one of the modules has a non-zero schema
Update README.md to talk about the linker
Do not freak out if an imported built-in variable has no export
This lets us write smaller test cases with the IrLoader, avoiding
boilerplate for function begin/end, and basic block begin/end.
Also ForEachInst is more forgiving of cases where a basic block
doesn't have a label, and when a function doesn't have a defining
or end instruction.
Also:
- Add const forms of ForEachInst
- Rewrite Module::ToBinary in terms of ForEachInst
- Add Instruction::ToBinaryWithoutAttachedDebugInsts
- Delete the ToBinary method on Function, BasicBlock, and Instruction
since it can now be implemented with ForEachInst in a less confusing
way, e.g. without recursion.
- Preserve debug line instructions on OpFunctionEnd (and store that
instruction as a unique-pointer, for regularity).
Previously we use vectors of objects and move semantics to handle
ownership. That approach has the flaw that inserting an object into
the middle of a vector, which may trigger a vector reallocation,
can invalidate some addresses taken from instructions.
Now the in-memory representation internally uses vector of unique
pointers to handle ownership. Since objects are explicitly heap-
allocated now, pointers to them won't be invalidated by vector
resizing anymore.
