DXC does not do a good job of recognizing which variables need to be
on the entry point for which functions. This is because it does not
want to have to walk the call tree to determine which instructions
are reachable from which entry points.
This is also useful if the same input variable gets used from two
different shader, but the uses in one get optimized away.
Will parially fix
https://github.com/microsoft/DirectXShaderCompiler/issues/4621. Will not
fix code compiled with -fcgl.
The optimizer is able to preserve the interface variables of the
shaders, but that feature has not been exposed to the command line
tool.
This commit adds an option `--preserve-interface` to spirv-opt that will
cause all calls to ADCE to leave the input and output variables, even if
the variable is unused. It will apply regardless of where the option
appears on the command line.
Fixes#5522
Certain versions of GCC warn about these variables being potentially uninitialized when used.
I believe this is a false-positive, but zero-init'ing them is a safe way to fix this.
spirv-link requires that memory models match between its input files.
Ensure this is the case by always returning SuccessWithChange and
always changing the memory model to match the instrumentation
code in Vulkan-ValidationLayers.
Also, disable the DCE pass in the --inst-* command line options, since
it will only work after linking.
Add a new legalization pass to dedupe invocation interlock instructions
DXC will be adding support for HLSL's rasterizer ordered views by using
the SPV_EXT_fragment_shader_interlock_extension. That extension
stipulates that if an entry point has an interlock ordering execution
mode, it must dynamically execute OpBeginInvocationInterlockEXT and
OpEndInvocationInterlockEXT, in that order, exactly once. This would be
difficult to determine in DXC's SPIR-V backend, so instead we will emit
these instructions potentially multiple times, and use this legalization
pass to ensure that the final SPIR-V follows the specification.
This PR uses data-flow analysis to determine where to place begin and
end instructions; in essence, determining whether a block contains or is
preceded by a begin instruction is similar to a specialized case of a
reaching definitions analysis, where we have only a single definition,
such as `bool has_begun = false`. For this simpler case, we can compute
the set of blocks using BFS to determine the reachability of the begin
instruction.
We need to do this for both begin and end instructions, so I have
generalized portions of the code to run both forward and backward over
the CFG for each respective case.
These functions are getting far too complicated to code in SPIRV-Tools
C++. Replace them with import stubs so that the real implementations
can live in Vulkan-ValidationLayers where they belong.
VVL will need to define these functions in spirv and link them to the
instrumented version of the user's shader.
From here on out, VVL can redefine the functions and any data they use
without updating SPIRV-Tools. Changing the function declarations will
still require both VVL and SPIRV-Tools to be updated in lock step.
Simplify what we add to user code by moving most of it into a function
that checks both that the descriptor index is in bounds and the
initialization state. Move error logging into this function as
well.
Remove many options to turn off parts of the instrumentation,
because there were far too many permutations to keep working and
test properly.
Combine Buffer and TexBuffer error checking. This requires that VVL
set the length of TexBuffers in the descriptor input state, rather
than relying on the instrumentation code to call OpImageQuerySize.
Since the error log includes the descriptor set and binding numbers
we can use a single OOB error code rather than having 4 per-type
error codes.
Since the error codes are getting renumbered, make them start at 1
rather than 0 so it is easier to determine if the error code was
actually set by the instrumentation.
This can cause interface incompatibility and should only be done
if ADCE has been applied to the following shader in the pipeline.
For this reason this capability is not available through the CLI
but rather only non-default through the API. This functionality is
intended as part of a larger cross-shader dead code elimination
sequence.
Safe version will only optimize vertex shaders. All other shaders will
succeed without change.
Change --eliminate-dead-input-components to use new safe version.
Unsafe version (allowing non-vertex shaders) currently only available
through API. Should only be used in combination with other optimizations
to keep interfaces consistent. See optimizer.hpp for more details.
This pass eliminates components of output variables that are not stored
to. Currently this just eliminates trailing components of arrays and
structs, all of which are dead.
WARNING: This pass is not designed to be a standalone pass as it can
cause interface incompatibiliies with the following shader in the
pipeline. See the comment in optimizer.hpp for best usage. This pass is
currently available only through the API; it is not available in the CLI.
This commit also fixes a bug in CreateDecoration() which is part of the
system of generating SPIR-V from the Type manager.
This adds two passes to accomplish this: one pass to analyze a shader
to determine the input slots that are live. The second pass is run on
the preceding shader to eliminate any stores to output slots that are
not consumed by the following shader.
These passes support vert, tesc, tese, geom, and frag shaders.
These passes are currently only available through the API.
These passes together with dead code elimination, and elimination of
dead input and output components and variables (WIP), will allow users
to do dead code elimination across shader boundaries.
There is an assert that verifies that the binary did not change when the
optimizer said that it did not. However, if the input binary is in big endian
format, the optimizer will encode the optimized binary in little endian. This
causes the assert to fail. Since we do not believe that anybody cares about a
big endien formate, we will disable the assert in that case.
Fixes#4722
spirv validation require OpFunctionCall with memory object, usually this
is non issue as all the functions are inlined.
This pass deal with some case for
DontInline function. accesschain input operand would be replaced new
created variable
Swift shader needs a way to inline all functions, even those marked as
DontInline. See https://github.com/KhronosGroup/SPIRV-Tools/pull/4471.
This implements the suggestion I made in the PR. We add a pass that
will remove the DontInline function control, so that the inlining passes
will inline them.
SwiftShader will still have to modify their code to add this pass before
the other passes are run.
Add a pass to spread Volatile semantics to variables with SMIDNV,
WarpIDNV, SubgroupSize, SubgroupLocalInvocationId, SubgroupEqMask,
SubgroupGeMask, SubgroupGtMask, SubgroupLeMask, or SubgroupLtMask BuiltIn
decorations or OpLoad for them when the shader model is the ray
generation, closest hit, miss, intersection, or callable shaders. This
pass can be used for VUID-StandaloneSpirv-VulkanMemoryModel-04678 and
VUID-StandaloneSpirv-VulkanMemoryModel-04679 (See "Standalone SPIR-V
Validation" section of Vulkan spec "Appendix A: Vulkan Environment for
SPIR-V").
Handle variables used by multiple entry points:
1. Update error check to make it working regardless of the order of
entry points.
2. For a variable, if it is used by two entry points E1 and E2 and
it needs the Volatile semantics for E1 while it does not for E2
- If VulkanMemoryModel capability is enabled, which means we have to
set memory operation of load instructions for the variable, we
update load instructions in E1, but do not update the ones in E2.
- If VulkanMemoryModel capability is disabled, which means we have
to add Volatile decoration for the variable, we report an error
because E1 needs to add Volatile decoration for the variable while
E2 does not.
For the simplicity of the implementation, we assume that all functions
other than entry point functions are inlined.
In https://github.com/KhronosGroup/SPIRV-Tools/pull/3110, the strip reflect
pass was changed to also remove all explicitly nonsemantic instructions. This
makes it so that the name of the pass no longer reflects what the pass actually
does. This change renames the pass so that it reflects what the pass actaully does.
The change in
commit 4ac8e5e541
Author: Greg Fischer <greg@lunarg.com>
Date: Wed Sep 15 12:38:34 2021 -0600
Add preserve_interface mode to aggressive_dead_code_elim (#4520)
Broke the C++ ABI for spirv-tools shared libraries on Linux, for not a great reason.
Restore the previous ABI.
convert-to-sampled-image pass converts images and/or samplers with
given pairs of descriptor set and binding to sampled image.
If a pair of an image and a sampler have the same pair of descriptor
set and binding that is one of the given pairs, they will be
converted to a sampled image. In addition, if only an image has the
descriptor set and binding that is one of the given pairs, it will
be converted to a sampled image as well.
For example, when we have
%a = OpLoad %type_2d_image %texture
%b = OpLoad %type_sampler %sampler
%combined = OpSampledImage %type_sampled_image %a %b
%value = OpImageSampleExplicitLod %v4float %combined ...
1. If %texture and %sampler have the same descriptor set and binding
%combine_texture_and_sampler = OpVaraible %ptr_type_sampled_image_Uniform
...
%combined = OpLoad %type_sampled_image %combine_texture_and_sampler
%value = OpImageSampleExplicitLod %v4float %combined ...
2. If %texture and %sampler have different pairs of descriptor set and binding
%a = OpLoad %type_sampled_image %texture
%extracted_image = OpImage %type_2d_image %a
%b = OpLoad %type_sampler %sampler
%combined = OpSampledImage %type_sampled_image %extracted_image %b
%value = OpImageSampleExplicitLod %v4float %combined ...
The new pass will removed interface variable on the OpEntryPoint instruction when they are not statically referenced in the call tree of the entry point.
It can be enabled on the command line using the options `remove-unused-interface-variables`.
This pass converts an internal form of GLSLstd450 Interpolate ops
to the externally valid form. The external form takes the lvalue
of the interpolant. The internal form can do a load of the interpolant.
The pass replaces the load with its pointer. The internal form is
generated by glslang and possibly other frontends for HLSL shaders.
The new pass is called as part of HLSL legalization after all
propagation is complete.
Also adds internal interpolate form to pre-legalization validation
Propagating the OpLine/OpNoLine to preserve the debug information
through transformations results in integrity check failures because of
the extra line instructions. This commit lets spirv-opt skip the
integrity check when the code contains OpLine or OpNoLine.
This instruments ImageRead, ImageWrite and ImageFetch when applied to
texel buffers.
Also add new (but not yet generated) buffer OOB error codes differentiated
for VUID classification.
Removing PropagateLineInfoPass and RedundantLineInfoElimPass from
56d0f5035 makes unit tests of many open source projects fail.
It will happen before submitting this glslang PR
https://github.com/KhronosGroup/glslang/pull/2440. This commit will be
git-reverted after merging the glslang PR.
Based on the OpLine spec, an OpLine instruction must be applied to
the instructions physically following it up to the first occurrence
of the next end of block, the next OpLine instruction, or the next
OpNoLine instruction.
```
OpLine %file 0 0
OpNoLine
OpLine %file 1 1
OpStore %foo %int_1
%value = OpLoad %int %foo
OpLine %file 2 2
```
For the above code, the current spirv-opt keeps three line
instructions `OpLine %file 0 0`, `OpNoLine`, and `OpLine %file 1 1`
in `std::vector<Instruction> dbg_line_insts_` of Instruction class
for `OpStore %foo %int_1`. It does not put any line instruction to
`std::vector<Instruction> dbg_line_insts_` of
`%value = OpLoad %int %foo` even though `OpLine %file 1 1` must be
applied to `%value = OpLoad %int %foo` based on the spec.
This results in the missing line information for
`%value = OpLoad %int %foo` while each spirv-opt pass optimizes the
code. We have to put `OpLine %file 1 1` to
`std::vector<Instruction> dbg_line_insts_` of
both `%value = OpLoad %int %foo` and `OpStore %foo %int_1`.
This commit conducts the line instruction propagation and skips
emitting the eliminated line instructions at the end, which are the same
with PropagateLineInfoPass and RedundantLineInfoElimPass. This
commit removes PropagateLineInfoPass and RedundantLineInfoElimPass.
KhronosGroup/glslang#2440 is a related PR that stop using
PropagateLineInfoPass and RedundantLineInfoElimPass from glslang.
When the code in this PR applied, the glslang tests will pass.
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.
Create a pass to instrument OpDebugPrintf instructions. This pass replaces all OpDebugPrintf instructions with instructions to write a record containing the string id and the all specified values into a special printf output buffer (if space allows). This pass is designed to support the printf validation in the Vulkan validation layers.
Fixes#3210
