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.
We currently run merge-return on all functions, but
dead-branch-elimination only runs on function reachable from an entry
point or exported function. Since dead-branch-elimination is needed for
merge-return, they have to match.
Fixes#1976.
In logical addressing mode, we are not allowed to generate variables
pointers. There is already a check for OpSelect. However, OpPhi
and OpPtrAccessChain are not checked to make sure it does not
generate an variable pointer. I've added those checks.
Fixes#1957.
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.
* MakePointerVisibleKHR cannot be used with OpStore
* MakePointerAvailableKHR cannot be used with OpLoad
* MakePointerAvailableKHR and MakePointerVisibleKHR both require
NonPrivatePointerKHR
* NonPrivatePointerKHR is limited to a subset of storage classes
* many tests
* Validation checks for new image operands MakeTexelAvailableKHR and
MakeTexelVisibleKHR
* added tests
* Tests that NonPrivateTexelKHR is accepted for all image operands
Updating test environments
* fixed build errors
* changed image types for *FetchSuccess tests to use a type defined in
1.3 shader body
Merge return assumes that the only unreachable blocks are those needed
to keep the structured cfg valid. Even those must be essentially empty
blocks.
If this is not the case, we get unpredictable behaviour. This commit
add a check in merge return, and emits an error if it is not the case.
Added a pass of dead branch elimination before merge return in both the
performance and size passes. It is a precondition of merge return.
Fixes#1962.
The current implementation in the folder when seeing a division by zero
is to assert. In the release build, the compiler will attempt to
compute the value, which causes its own problems.
The solution I will go with is to fold the division, and just give it
the value of 0. The same goes for remainder and mod operations.
Fixes#1961.
This commit checks the following when Shader capability exists:
"The FPRoundingMode decoration can be applied only to a width-only
conversion instruction that is used as the Object operand of an
OpStore storing through a pointer to a 16-bit floating-point object
in the StorageBuffer, Uniform, PushConstant, Input, or Output
Storage Classes.".
The HlslCounterBufferGOOGLE that was introduced changed the OpDecorateId
so that is can now reference an id other than the target. If that other
id is used only in the decoration, then the definition of the id will be
removed because decoration do not count as real uses.
However, if the target of the decoration is still live the decoration
will not be removed. This leaves a reference to an id that is not
defined.
There are two solutions to consider. The first is that is the decoration
is kept, then the definition of the id should be kept live. Implementing
this change would be involved because the way ADCE handles decorations
will have to be reimplemented.
The other solution is to remove the decoration the id is otherwise dead.
This works for this specific case. Also this is the more desirable
behaviour in this case. The id will always be the id of a variable that
belongs to a descriptor set. If that variable is not bound and we do
not remove it, the driver will complain.
I chose to implement the second solution. The first will be left to when
a case for it comes up.
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/1885.
This commit will change the message for unknown extensions from an error
to a warning.
Code was added to limit the number of warning messages so that consummer
of the messages are not overwhelmed. This is standard practice in
compilers.
Many other issues were found at while looking into this. They have been
documented in #1950.
Fixes http://crbug.com/875547.
* Check rules from Execution Mode tables, 2.16.2 and the Vulkan
environment spec
* Allows MeshNV execution model with the following execution modes
* LocalSize, LocalSizeId, OutputPoints and OutputVertices
* Done to not break their validation
There are a few spots where copy propagate arrays is trying
to go from a Type to an id, but the type is not unique. When generating
code this pass needs specific ids, otherwise we get type mismatches.
However, the ambigous types means we can sometimes get the wrong type
and generate invalid code.
That code has been rewritten to not rely on the type manager, and just
look at the instructions instead.
I have opened https://github.com/KhronosGroup/SPIRV-Tools/issues/1939 to
try to get a way to make this more robust.
In DecorationManager::RemoveDecorationsFrom, we do not remove the id
from a decoration group if the group has no decorations. This causes
problems because KillNamesAndDecorates is suppose to remove all
references to the id, but in this case, there is still a reference.
This is fixed by adding a special case.
Also, there is the possibility of a double free because
RemoveDecorationsFrom will delete the instructions defining |id| when
|id| is a decoration group. Later, KillInst would later write to memory
that has been deleted when trying to turn it into a Nop. To fix this,
we will only remove the decorations that use |id| and not its definition
in RemoveDecorationsFrom.
OpPhi instruction must appear before all non-OpPhi instructions
except for OpLine. Without this commit, Validator does not check
the case that an OpPhi is preceeded by an OpLine and the OpLine is
preceeded by a non-OpPhi instruction that is not OpLine.
Checked all instructions whose object is OpTypeSampledImage or
OpTypeImage as suggested in #487. OpImageTexelPointer instruction
is missing and others look good. This commit adds only
OpImageTexelPointer.
This CL removes the use of SetContextMessageConsumer from the
binary_parse_test tests and creates a Context object and uses
SetMessageConsumer instead.
Instead of using the source/table.h methods, this CL switches the stats
tool to use the spvtools::Context class and assign the message consumer
through the public API.
A limit of 0 for the scalar replacement options it used to indicate that
there is no limit. The current implementation does not allow 0. This
should be fixed.
It seems like the current implementation of KillNameAndDecorates does
not handle group decorations correctly. The id being removed is not
removed from the OpGroupDecorate instructions. Even worst, any
decorations that apply to that group are removed.
The solution is to use the function in the decoration manager that will
remove the decorations and update the instructions instead of doing the
work itself.
Adds unrolling to the legalization passes.
After enabling unrolling I found a bug when there is a self-referencing
phi node. That has been fixed.
The test that checks for that the order of optimizations is correct also
needed to be updated.
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.
* Create structed cfg analysis.
There are lots of optimization that have to traverse the CFG in a
structured order just because it wants to know which constructs a
basic block in contained in. This adds extra complexity to these
optimizations, for causes too much refactoring of older optimizations.
To help with this problem, I have written an analysis that can give this
information.
* Identify branches breaking from loops.
Dead branch elimination does a search for a conditional branch to the
end of the current selection construct. This search assumes that the
only way to leave the construct is through the merge node. But that is
not true. The code can jump to the merge node of a loop that contains
the construct.
The search needs to take this into consideration.
In merge blocks, we do not allow the merging of two blocks with merge
instructions. This is because if the two block are merged only 1 of
those instructions can exists. However, if the successor block is the
merge block of the predecessor, then we can delete the merge instruction
in the predecessor. In this case, we are able to merge the blocks.
* Create a new entry point for the optimizer
Creates a new struct to hold the options for the optimizer, and creates
an entry point that take the optimizer options as a parameter.
The old entry point that takes validator options are now deprecated.
The validator options will be one of the optimizer options.
Part of the optimizer options will also be the upper bound on the id bound.
* Add a command line option to set the max value for the id bound. The default is 0x3FFFFF.
* Modify `TakeNextIdBound` to return 0 when the limit is reached.
