Specifically, DebugSourceContinued, DebugCompilationUnit, and
DebugEntryPoint. These instructions are top-level instructions
which do not or may not have a user except for the tool and so
should not be eliminated.
Which functions are processed is determined by which ones are on the
call tree from the entry points before dead code is removed. So it is
possible that a function is process because it is called from an entry
point, but the CFG is not cleaned up because the call to the function
was removed.
The fix is to process and cleanup every function in the module. Since
all of the dead functions would have already been removed in an earlier
step of DCE, it should not make a different in compile time.
Fixes#4731
* Fix endianness of string literals
To get correct and consistent encoding and decoding of string literals
on big-endian platforms, use spvtools::utils::MakeString and MakeVector
(or wrapper functions) consistently for handling string literals.
- add variant of MakeVector that encodes a string literal into an
existing vector of words
- add variants of MakeString
- add a wrapper spvDecodeLiteralStringOperand in source/
- fix wrapper Operand::AsString to use MakeString (source/opt)
- remove Operand::AsCString as broken and unused
- add a variant of GetOperandAs for string literals (source/val)
... and apply those wrappers throughout the code.
Fixes #149
* Extend round trip test for StringLiterals to flip word order
In the encoding/decoding roundtrip tests for string literals, include
a case that flips byte order in words after encoding and then checks for
successful decoding. That is, on a little-endian host flip to big-endian
byte order and then decode, and vice versa.
* BinaryParseTest.InstructionWithStringOperand: also flip byte order
Test binary parsing of string operands both with the host's and with the
reversed byte order.
* https://github.com/KhronosGroup/Vulkan-Docs/issues/666 clearly
specified that interfaces do not require an input if there is an
associated output
* ADCE can now remove unused input variables (though they are kept if
the preserve interfaces option is used)
Consider the new test case. The conditional branch in the continue
block is never marked as live. However, `IsDead` will say it is not
dead, so it does not get deleted. Because it was never marked as live,
`%false` was not mark as live either, but it gets deleted. This results
in invalid code.
To fix this properly, we had to reconsider how branches are handle. We
make the following changes:
1) Terminator instructions that are not branch or OpUnreachable must be
kept, so they are marked as live when initializing the worklist.
2) Branches and OpUnreachable instructions are marked as live if
a) the block does not have a merge instruction and another instruction
in the block is marked as live, or
b) the merge instruction in the same block is marked as live.
3) Any instruction that is not marked as live is removed.
4) If a terminator is to be removed, an OpUnreachable is added. This
happens when the entire block is dead, and the block will be removed.
The OpUnreachable is generated to make sure the block still has a
terminator, and is valid.
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/4509.
Having IsLocalVar work only sometimes is something that could easily
lead to an error. This change refactors the code so that the function
can be called at any point. The current implementation was used because
we did not want to do multiple searches to see if a function was an
entry point or if it had a call. This was maintained by added a cache
that will store of a given function is an entry point with no calls.
* Have ADCE use cfg struct analysis (NFC)
ADCE has a lot of code and variables to keep track of
information that is easily obtains using the Struct
cfg analysis. Most of this change is to refactor the
code to have small functions to get the information
from the struct cfg analysis.
A few other changes small refactoring changes are
done.
* Factor out work list initialization in ADCE (NFC)
We move the code that will initially populate the work list into its own
function. We also simplify the code by making use of the struct cfg
analysis. That way we can reduce the number of tables used to track
information as we traverse the CFG.
Debug[No]Line are tracked and optimized using the same mechanism that tracks
and optimizes Op[No]Line.
Also:
- Fix missing DebugScope at top of block.
- Allow scalar replacement of access chain in DebugDeclare
Includes:
- Shift to use of spirv-header extinst.nonsemantic.shader grammar.json
- Remove extinst.nonsemantic.vulkan.debuginfo.100.grammar.json
- Enable all optimizations for Shader.DebugInfo
Also fixes scalar replacement to only insert DebugValue after all
OpVariables. This is not necessary for OpenCL.DebugInfo, but it is
for Shader.DebugInfo.
Likewise, fixes Private-to-Local to insert DebugDeclare after all
OpVariables.
Also fixes inlining to handle FunctionDefinition which can show up
after first block if early return processing happens.
Co-authored-by: baldurk <baldurk@baldurk.org>
ADCE does not handle exported functions. This was an explicit decision
because we did not believe that the linkage attribute could be used in
shaders, but it can now. This change has been made.
While fixing this error, I noticed that the OpName for labels is
sometimes removed because the label instructions are not marked
explicitly marked as live. This has able been fixed.
* Initial support for SPV_KHR_integer_dot_product
- Adds new operand types for packed-vector-format
- Moves ray tracing enums to the end
- PackedVectorFormat is a new optional operand type, so it requires
special handling in grammar table generation.
- Add SPV_KHR_integer_dot_product to optimizer whitelists.
- Pass-through validation: valid cases pass validation
Validation errors are not checked.
- Update SPIRV-Headers
Patch by David Neto <dneto@google.com>
Rebase and minor tweaks by Kevin Petit <kevin.petit@arm.com>
Signed-off-by: David Neto <dneto@google.com>
Signed-off-by: Kevin Petit <kevin.petit@arm.com>
Change-Id: Icb41741cb7f0f1063e5541ce25e5ba6c02266d2c
* format fixes
Change-Id: I35c82ec27bded3d1b62373fa6daec3ffd91105a3
Similar to [1] DCE should be ran when this extension is enabled to
prevent unused bindings from showing up (in particular atomic counters
attached to buffers).
[1]: https://github.com/KhronosGroup/SPIRV-Tools/pull/4047
In the existing code, ADCE pass does not check DebugScope of an
instruction when it checks the users of each instruction, which results
in removing OpenCL.Debug.100 instructions that are only used by
DebugScope. This commit lets ADCE pass add DebugScope of an instruction
to the live instruction set when the instruction is added to the live
instruction set.
* 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
Essentially, it marks all DebugInfo instructions in functions (and their operands) as live. It treats DebugDeclare and DebugValue with Deref as loads and so marks Stores of their variables as live.
It marks each DebugGlobalVariables as live except for its variable. After closure, it rechecks if the variable is live. If not, the DebugGlobalVariable instruction's variable operand is set to DebugInfoNone, per the DebugInfo spec.
When there are multiple entries and the shader has a variable with
WorkGroup storage class, those multiple entry functions store values to
the variable. Since ADCE pass uses def-use chains to propagate the work
list, some of instructions in the work list are not actually a part of
the currently processed function. As a result, it adds instructions in
other functions and put them in |live_insts_|. However, it does not
have the control flow information for those instructions in other
functions i.e., |block2headerBranch_| and |header2nextHeaderBranch_|.
When it processes those instructions (they are added when it processes a
different function), it skips handling them because they are already in
|live_insts_| and does not check |block2headerBranch_| and
|header2nextHeaderBranch_|, which results in skipping some branches.
Even though those branches are live branches, it considers they are dead
branches.
This also fixes ADCE to not remove possibly needed OpTypeForwardPointer.
The bug, its fix and the corresponding test have a circular dependency
with the extension, so they are packaged together.
* Process OpDecorateId in ADCE
When there is an OpDecorateId instruction that is live,
the ids that is references must be kept live. This change
adds them to the worklist.
I've also updated a validator check to allow OpDecorateId
to be able to apply to decoration groups.
Fixes#1759.
* Remove dead code.
Fixes#2551
* Add support for 1.4 entry point interface lists
* only input and output variables are automatically live
* can clean up interfaces after DCE
* added tests
* allow opt tests to specify a target environment
* Check var pointer capability in ADCE.
* Check var ptr capability for common uniform.
* Check var ptr capability in access chain convert.
Since we want this pass to run even if there are variable pointer on
storage buffers, we had to remove asserts that assumed there were no
variable pointers. The functions with the asserts will now work, it
becomes the responsibility of the callers to deal with the output as
appropriate.
* Single block elimination and variable pointers.
It seems like the code in local single block elimination is able to
handle cases with variable pointers already. This is because the
function `HasOnlySupportedRefs` ensures that variables that feed a
variable pointer are not candidates.
* Single store elimination and variable pointers.
It seems like the code in local single stroe elimination is able to
handle cases with variable pointers already. This is because the
function `FindSingleStoreAndCheckUses` ensures that variables that feed
a variable pointer are not candidates.
* SSA rewriter and variable pointers.
It seems like the code in the two passes that call the SSA rewriter are
able to handle cases with variable pointers already. This is because the
function `HasOnlySupportedRefs` ensures that variables that feed
a variable pointer are not candidates.
Fixes#2458.
Fixes#2456
* When eliminating a structured construct that has an unreachable merge,
replace that unreachable terminator with an appropriate return
* New tests
* Invalidate the decoration manager at the start of ADCE.
If the decoration manager is kept live the the contex will try to keep
it up to date. ADCE deals with group decorations by changing the
operands in |OpGroupDecorate| instructions directly without informing
the decoration manager. This puts it in an invalid state, which will
cause an error when the context tries to update it. To Avoid this
problem, we will invalidate the decoration manager upfront.
At the same time, the decoration manager is now considered when checking
the consistency of the decoration manager.
* 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.
ADCE liveness algorithm should treat OpUnreachable at least like other
branch instructions. It was being treated as always live which was
preventing useless structured constructs from being eliminated.
OpUnreachable is generated by dead branch elimination which is now
being required by merge return, so this fix should accompany that
change.
Was removing control structures which didn't have data dependency
with enclosed live loop and otherwise did not contain live code.
An example is a counting loop around a live loop.
Fixes#1967.
Consider atomics that load when analyzing live stores in ADCE.
Previously it asserted that the base of an OpImageTexelPointer should
be an image. It is actually a pointer to an image, so IsValidBasePointer
should suffice.