Commit Graph

46 Commits

Author SHA1 Message Date
Steven Perron
32af42616a
Change implementation of post order CFG traversal (#2543)
* Change implementation of post order CFG traversal

It seems like the recursion is going very deep, and causing some problem
is particular situations.  I've reimplemented the CFG post order
traversal to not use recursion.

Fixes #2539.
2019-04-29 17:09:20 -04:00
Paul Thomson
fcb8453104
reduce: fix loop to selection pass for loops with combined header/continue block (#2480)
* Fix #2478. The fix is to just not try to simplify such loops. 
* Also added `BasicBlock::MergeBlockId()` and `BasicBlock::ContinueBlockId()`. 
* Some minor changes to `structured_loop_to_selection_reduction_opportunity.cpp`. 
* Added test.
2019-03-29 11:29:24 +00:00
greg-lunarg
1e9fc1aac1 Add base and core bindless validation instrumentation classes (#2014)
* Add base and core bindless validation instrumentation classes

* Fix formatting.

* Few more formatting fixes

* Fix build failure

* More build fixes

* Need to call non-const functions in order.

Specifically, these are functions which call TakeNextId(). These need to
be called in a specific order to guarantee that tests which do exact
compares will work across all platforms. c++ pretty much does not
guarantee order of evaluation of operands, so any such functions need to
be called separately in individual statements to guarantee order.

* More ordering.

* And more ordering.

* And more formatting.

* Attempt to fix NDK build

* Another attempt to address NDK build problem.

* One more attempt at NDK build failure

* Add instrument.hpp to BUILD.gn

* Some name improvement in instrument.hpp

* Change all types in instrument.hpp to int.

* Improve documentation in instrument.hpp

* Format fixes

* Comment clean up in instrument.hpp

* imageInst -> image_inst

* Fix GetLabel() issue.
2018-11-08 13:54:54 -05:00
Steven Perron
80564a56ec
Keep analyses live in unrolling (#1929)
Add code to keep the def-use manger and the inst-to-block mapping up-to-date. This means we do not have to rebuild them later.

To make this work, we will have to have to find places to update the
def-use manager. Updating the def-use manager is not straight forward
because we are unrolling loops, and we have circular references.

This forces one pass to register all of the definitions. A second one
to analyze the uses. Also because there will be references to the new
instructions in the old code, we want to register the definitions of the
new instructions early, so we can update the uses of the older code as
we go along.

The inst-to-block mapping is not too difficult. It can be done as instructions are created.

Fixes #1928.
2018-09-26 17:36:27 -04:00
Steven Perron
7075c49923
Add dummy loop in merge-return. (#1896)
The current implementation of merge return can create bad, but correct,
code.  When it is not in a loop construct, it will insert a lot of
extra branch around code.  The potentially large number of branches are
bad.  At the same time, it can separate code store to variables from
its uses hiding the fact that the store dominates the load.

This hurts the later analysis because the compiler thinks that multiple
values can reach a load, when there is really only 1.  This poorer
analysis leads to missed optimizations.

The solution is to create a dummy loop around the entire body of the
function, then we can break from that loop with a single branch.  Also
only new merge nodes would be those at the end of loops meaning that
most analysies will not be hurt.

Remove dead code for cases that are no longer possible.

It seems like some drivers expect there the be an OpSelectionMerge
before conditional branches, even if they are not strictly needed.
So we add them.
2018-09-18 08:52:47 -04:00
Diego Novillo
4a4632264e Add IR dumping functions to use during debugging.
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.
2018-09-14 14:28:34 -04:00
dan sinclair
eda2cfbe12
Cleanup includes. (#1795)
This Cl cleans up the include paths to be relative to the top level
directory. Various include-what-you-use fixes have been added.
2018-08-03 15:06:09 -04:00
dan sinclair
58a6876cee
Rewrite include guards (#1793)
This CL rewrites the include guards to make PRESUBMIT.py include guard
check happy.
2018-08-03 08:05:33 -04:00
dan sinclair
c7da51a085
Cleanup extraneous namespace qualifies in source/opt. (#1716)
This CL follows up on the opt namespacing CLs by removing the
unnecessary opt:: and opt::analysis:: namespace prefixes.
2018-07-12 15:14:43 -04:00
dan sinclair
e6b953361d
Move the ir namespace to opt. (#1680)
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.
2018-07-09 11:32:29 -04:00
Victor Lomuller
0ec08c28c1 Add register liveness analysis.
For each function, the analysis determine which SSA registers are live
at the beginning of each basic block and which one are killed at
the end of the basic block.

It also includes utilities to simulate the register pressure for loop
fusion and fission.

The implementation is based on the paper "A non-iterative data-flow
algorithm for computing liveness sets in strict ssa programs" from
Boissinot et al.
2018-04-20 09:45:15 -04:00
Diego Novillo
735d8a579e SSA rewrite pass.
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).
2018-03-20 20:56:55 -04:00
Steven Perron
b3daa93b46 Change merge return pass to handle structured cfg.
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.
2018-03-19 13:49:04 -04:00
Victor Lomuller
3497a94460 Add loop unswitch pass.
It moves all conditional branching and switch whose conditions are loop
invariant and uniform. Before performing the loop unswitch we check that
the loop does not contain any instruction that would prevent it
(barriers, group instructions etc.).
2018-02-27 08:52:46 -05:00
Victor Lomuller
50e85c865c Add LoopUtils class to gather some loop transformation support.
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)
2018-02-01 15:35:09 -05:00
Alan Baker
2e93e806e4 Initial implementation of if conversion
* 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
2018-01-25 09:42:00 -08:00
Alan Baker
6587d3f8a3 Adding early exit versions of several ForEach* methods
* Looked through code for instances where code would benefit from early
exit
 * Added a corresponding WhileEach* method and updated the code
2018-01-12 17:05:09 -05:00
Alan Baker
672494da13 Adding ostream operators for IR structures
* 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
2018-01-12 11:19:58 -05:00
Alan Baker
1b6cfd3409 Rewriting dead branch elimination.
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
2018-01-09 12:21:39 -05:00
David Neto
a82a0ea886 Fix method comment for BasicBlock::MegeBlockIdIfAny
Fixes #1177
2018-01-08 10:42:02 -05:00
Pierre Moreau
7183ad526e Linker code cleanups
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
2018-01-05 13:28:44 -05:00
David Neto
ac9a828e6e dead branch elim: Track killed backedges
When deleting branches and blocks, also remove them from
the backedges set, in case they were there.

This prevents us from keeping stale pointers to deleted Instruction
objects.  That memory could be used later by another instruction,
incorrectly signaling that something has a backedge reference, and
the dead branch eliminator could end up deleting live blocks.

Adds accessor method ir::BasicBlock::terminator

Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/1168
2018-01-04 19:06:55 -05:00
Diego Novillo
5f100789fb Handle execution termination instructions when building edges.
This fixes issue https://github.com/KhronosGroup/SPIRV-Tools/issues/1153.

When building CFG edges, edges out of a OpKill and OpUnreachable
instruction should be directed to the CFG's pseudo exit block.
2018-01-03 15:25:03 -05:00
Stephen McGroarty
8ba68fa9b9 Dominator Tree Analysis (#3)
Support for dominator and post dominator analysis on ir::Functions. This patch contains a DominatorTree class for building the tree and DominatorAnalysis and DominatorAnalysisPass classes for interfacing and caching the built trees.
2017-12-05 22:59:43 -05:00
Steven Perron
65046eca7c Change IRContext::KillInst to delete instructions.
The current method of removing an instruction is to call ToNop.  The
problem with this is that it leaves around an instruction that later
passes will look at.  We should just delete the instruction.

In MemPass there is a utility routine called DCEInst.  It can delete
essentially any instruction, which can invalidate pointers now that they
are actually deleted.  The interface was changed to add a call back that
can be used to update any local data structures that contain
ir::Intruction*.
2017-12-04 11:07:45 -05:00
Diego Novillo
74327845aa Generic value propagation engine.
This class implements a generic value propagation algorithm based on the
conditional constant propagation algorithm proposed in

     Constant propagation with conditional branches,
     Wegman and Zadeck, ACM TOPLAS 13(2):181-210.

The implementation is based on

     A Propagation Engine for GCC
     Diego Novillo, GCC Summit 2005
     http://ols.fedoraproject.org/GCC/Reprints-2005/novillo-Reprint.pdf

The purpose of this implementation is to act as a common framework for any
transformation that needs to propagate values from statements producing new
values to statements using those values.
2017-11-27 23:32:06 -05:00
Alan Baker
a771713e42 Adding an unique id to Instruction generated by IRContext
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
2017-11-20 17:49:10 -05:00
Diego Novillo
fef669f30f Add a new class opt::CFG to represent the CFG for the module.
This class moves some of the CFG-related functionality into a new
class opt::CFG.  There is some other code related to the CFG in the
inliner and in opt::LocalSingleStoreElimPass that should also be moved,
but that require more changes than this pure restructuring.

I will move those bits in a follow-up PR.

Currently, the CFG is computed every time a pass is instantiated, but
this should be later moved to the new IRContext class that @s-perron is
working on.

Other re-factoring:

- Add BasicBlock::ContinueBlockIdIfAny. Re-factored out of MergeBlockIdIfAny
- Rewrite IsLoopHeader in terms of GetLoopMergeInst.
- Run clang-format on some files.
2017-11-02 10:37:03 -04:00
Steven Perron
94dc66b74d Change the sections in the module to use the InstructionList class.
This change will replace a number of the
std::vector<std::unique_ptr<Instruction>> member of the module to
InstructionList.  This is for consistency and to make it easier to
delete instructions that are no longer needed.
2017-10-25 15:52:06 -04:00
Steven Perron
bb7802b18c Change BasicBlock to use InstructionList to hold instructions.
This is the first step in replacing the std::vector of Instruction
pointers to using and intrusive linked list.

To this end, we created the InstructionList class.  It inherites from
the IntrusiveList class, but add the extra concept of ownership.  An
InstructionList owns the instruction that are in it.  This is to be
consistent with the current ownership rules where the vector owns the
instruction that are in it.

The other larger change is that the inst_ member of the BasicBlock class
was changed to using the InstructionList class.

Added test for the InsertBefore functions, and making sure that the
InstructionList destructor will delete the elements that it contains.

I've also add extra comments to explain ownership a little better.
2017-10-20 12:37:44 -04:00
David Neto
8ec62deb23 The reviewed cfg_cleanup optimize pass 2017-10-19 15:28:09 -04:00
Pierre Moreau
86627f7b3f Implement Linker (module combiner)
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
2017-10-06 18:33:53 -04:00
David Neto
cff2cd3343 BasicBlock: add ctail, GetMergeInst, GetLoopMergeInst 2017-09-01 11:01:36 -04:00
GregF
7c3de19ce7 DeadBranchElim: Fix dead block detection to ignore backedges
- DeadBranchElim: Make sure to mark orphan'd merge blocks and continue
targets as live.
- Add test with loop in dead branch
- Add test that orphan'd merge block is handled.

Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/776
2017-08-30 13:37:46 -04:00
GregF
ad1d0351a0 BlockMerge: Add BlockMergePass
Also, add BasicBlock::tail()
2017-06-27 11:31:33 -04:00
Greg Fischer
bba812f4e4 Inline: Inline early return function if no returns in loop. 2017-05-12 17:18:00 -04:00
GregF
a107d349e3 Inline: Do not inline functions with multiple returns (for now) 2017-04-25 16:50:57 -06:00
Greg Fischer
04fcc66743 Add exhaustive function call inlining to spirv-opt
Inlining is done for all functions designated as entry points.

Add optional validation to test fixture method SinglePassRunAndCheck.
2017-03-29 18:02:40 -04:00
David Srbecky
b85997a1df Add various accessors needed to read and edit SPIRV code. 2017-03-29 14:38:57 +01:00
David Neto
9fc8658ef3 Relicense SPIRV-Tools under Apache 2.0
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/383

Finalize v2016.4
2016-09-02 10:00:29 -04:00
David Neto
cc60caba1d IrLoader gracefully handles incomplete blocks and functions
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.
2016-08-26 10:15:15 -04:00
David Neto
97fc6aa3b8 ForEachInst optionally runs on attached debug line insts
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).
2016-08-25 11:43:22 -04:00
Lei Zhang
4b3247feba Avoid non-oneliner definition in class and add missing iterators. 2016-08-12 10:34:47 -04:00
Lei Zhang
80c94a4fa8 Change the interfaces of in-memory representation to use pointers.
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.
2016-08-10 12:11:33 -04:00
Lei Zhang
abf8f6413c Promote ir namespace and create draft libspirv.{h|c}pp. 2016-06-28 14:52:34 -04:00
Lei Zhang
3df8f7cebd Add classes for representing SPIR-V language constructs in memory. 2016-06-24 20:54:06 -04:00