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.
* Analyze uses for all instructions.
The def-use manager needs to fill in the `inst_to_used_ids_` field for
every instruction. This means we have to analyze the uses for every
instruction, even if they do not have any uses.
This mistake was not found earlier because there was a typo in the
equality check for def-use managers. No new tests are needed.
While looking into this I found redundant work in block merge. Cleaning
that up at the same time.
* Fix other transformations
Aggressive dead code elimination did not update the OpGroupDecorate
and the OpGroupMemberDecorate instructions properly when they are
updated. That is fixed.
Dead branch elimination did not analyze the OpUnreachable instructions
that is would add. That is taken care of.
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.
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.
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.
We currently register decorations in the first pass through the
instructions. This is a problem because the validator has not even
checked if the decoration instructions are valid yet. This can lead to
unexpected behaviour from these side table. For example, in
https://github.com/KhronosGroup/SPIRV-Tools/issues/1882, we use 5GB of
data to store 1 decoration for ids that are not even defined.
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/1882.
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.
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.
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.
