We want to be able to apply scalar replacement on variables that have
the AliasPointer and RestrictPointer decorations.
This exposed a bug that needs to be fixed as well.
Scalar replacement sometimes uses the type manager to get the type id for the
variables it is creating. The variable type is a pointer to a pointee
type. Currently, scalar replacement uses the type manager when only if
the pointee type has to be unique in the module. This is done to try to avoid the case where two type hash to the same
value in the type manager, and it returns the wrong one.
However, this check is not the correct check. Pointer types still have to be
unique in the spir-v module. However, two unique pointer types can hash
to the same value if their pointee types are isomorphic. For example,
%s1 = OpTypeStruct %int
%s2 = OpTypeStruct %int
; %p1 and %p2 will hash to the same value even though they are still
; considered "unique".
%p1 = OpTypePointer Function %s1
%p2 = OpTypePointer Function %s2
To fix this, we now use FindPointerToType, and we modified TypeManager::IsUnique to refer to the whether or not a type will hash to a unique value and say that pointers are not unique.
Fixes#5196
Scalar replacement generates a null when there value for a member will
not be used. The null is used to make sure things are
deterministic in case there is an error.
However, some type cannot be null, so we will change that to use undef.
To keep the code simpler we will always use the undef.
Fixes#3996
Spirv-opt has not had to handle module with function declarations. This
lead many passes to assume that every function has a body. This is not
always true. This commit will modify a number of passes to handle
function declarations.
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/4443
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>
spirv-opt has a bug that `DebugInfoManager::AddDebugValueWithIndex()` does not
preserve `Indexes` operands of
[DebugValue](https://www.khronos.org/registry/spir-v/specs/unified1/OpenCL.DebugInfo.100.html#DebugValue).
It has to preserve all of those `Indexes` operands, but it preserves only the first index
operand.
This PR removes `DebugInfoManager::AddDebugValueWithIndex()` and lets the spirv-opt
use `DebugInfoManager::AddDebugValueForDecl()`.
`DebugInfoManager::AddDebugValueForDecl()` preserves the Indexes operand correctly.
1. Set the debug scope and line information for the new replacement
instructions.
2. Replace DebugDeclare and DebugValue if their OpVariable or value
operands are replaced by scalars. It uses 'Indexes' operand of
DebugValue. For example,
struct S { int a; int b;}
S foo; // before scalar replacement
int foo_a; // after scalar replacement
int foo_b;
DebugDeclare %dbg_foo %foo %null_expr // before
DebugValue %dbg_foo %foo_a %Deref_expr 0 // after
DebugValue %dbg_foo %foo_b %Deref_expr 1 // means Value(foo.members[1]) == Deref(%foo_b)
* Handle extract with no indexes
It is possible that OpCompositeExtract instructions will not have any
indexes. This is not handled well by scalar replacement and instruction
folding.
Fixes https://crbug.com/1006435
* Fix typo.
Now we need to handle id overflow when we overflow while replacing uses of the variable. While looking at this code, I noticed an error in the way we handle access chains that cannot be replaced because of overflow. Name it will make some change, and then give up by returning SuccessWithoutChange. But it was changed.
This is fixed up by returning Failure if we notice the error at the time of rewriting the users. This is for both id overflow or out-of-bounds accesses.
Code is added to "CheckUses" to remove variables that have out-of-bounds accesses from the candidate list, so we don't even try to rewrite its uses.
Fixes https://crbug.com/995032
If we run out of ids when creating a new variable, sroa does not recognize
the error, and continues doing work. This leads to segmentation faults.
Fixes https://crbug/969655
If a member of a struct has a relaxed precision, sroa will not split the
struct. This means we do not get all cases. This commit handles these
cases. The other part is that the decoration needs to be passed on to
the new variables.
Fixes#2786
Fixes#2768
* In scalar replacement, interpret access chain indexes as signed counts
* Use Constant::GetSignExtendedValue and Constant::GetZeroExtendedValue
where appropriate
* new tests
* Fix#2609 - Handle out-of-bounds scalar replacements.
When SROA tries to do a replacement for an OpAccessChain that is exactly
one element out of bounds, the code was trying to access its internal
array of replacements and segfaulting.
This protects the code from doing this, and it additionally fixes the
way SROA works by not returning failure when it refuses to do a
replacement. Instead of failing the optimization pass, SROA will now
simply refuse to do the replacement and keep going.
Additionally, this patch fixes the SROA logic to now return a proper status so we can
correctly state that the pass made no changes to the IR if it only found
invalid references.
There is a case where sroa is not handling id overflow gracefully. It
is handled and an error message is output when the ids overflow.
Fixes https://crbug.com/961030.
It is legal, but not generated by any SPIR-V producer: an OpAccessChain
with no indexes. This is essentially just a copy of the pointer.
I have decided to treat it like an OpCopyObject. In CheckUses, we
return that it is not okay.
When looking at this I realized that we had code in GetUsedComponents
that cannot be reached. If there is a use in an OpCopyObject the it
will not call GetUsedComponents. I removed that dead code.
Fixes https://crbug.com/918311.
We initially assumed that if the type manager returned the correct id
for the pointee type, that we would get the correct pointer type back,
but that is not true. See the unit test added with this commit. We
need to fall back to the linear search any time we are looking for a
pointer to a type that may not be unique.
At the same time, SROA considered an OpName on a variable to be a use of
the entire variable. That has been fixed.
Fixes#2209.
There are a few locations where we need to handle duplicate types. We
cannot merge them because they may be needed for reflection. When this
happens we need do some extra lookups in the type manager.
The specific fixes are:
1) When generating a constant through `GetDefiningInstruction` accept
and use an id for the desired type of the constant. This will make sure
you get the type that is needed.
2) In Private-to-local, make sure we to update the def-use chains when a
new pointer type is created.
3) In the type manager, make sure that `FindPointerToType` returns a
pointer that points to the given type and not a duplicate type.
4) In scalar replacment, make sure the null constants that are created
are the correct type.
Removes the limit on scalar replacement for the lagalization passes.
This is done by adding an option to the pass (and command line option)
to set the limit on maximum size of the composite that scalar
replacement is willing to divide.
Fixes#1494.
Currently in scalar replacement, we create a new variable for every
memeber of the composite being divided. It is often overkill, because
not all of those members will be used. This change will check which
elements are used and only create variable for the members that are
used.
This reduces the compile time for one set of shader from 248s to 165s.
Part of https://github.com/KhronosGroup/SPIRV-Tools/issues/1494.
Adds a scalar replacement pass. The pass considers all function scope
variables of composite type. If there are accesses to individual
elements (and it is legal) the pass replaces the variable with a
variable for each composite element and updates all the uses.
Added the pass to -O
Added NumUses and NumUsers to DefUseManager
Added some helper methods for the inst to block mapping in context
Added some helper methods for specific constant types
No longer generate duplicate pointer types.
* Now searches for an existing pointer of the appropriate type instead
of failing validation
* Fixed spec constant extracts
* Addressed changes for review
* Changed RunSinglePassAndMatch to be able to run validation
* current users do not enable it
Added handling of acceptable decorations.
* Decorations are also transfered where appropriate
Refactored extension checking into FeatureManager
* Context now owns a feature manager
* consciously NOT an analysis
* added some test
* fixed some minor issues related to decorates
* added some decorate related tests for scalar replacement
