Previously we use vectors of objects and move semantics to handle
ownership. That approach has the flaw that inserting an object into
the middle of a vector, which may trigger a vector reallocation,
can invalidate some addresses taken from instructions.
Now the in-memory representation internally uses vector of unique
pointers to handle ownership. Since objects are explicitly heap-
allocated now, pointers to them won't be invalidated by vector
resizing anymore.
The NEW behavior is to not dereference variables or interpret keywords
that have been quoted or bracketed.
For more information, see
https://cmake.org/cmake/help/v3.1/policy/CMP0054.html.
This is to suppress a warning when using CMake 3.1.3+.
- Find unreachable continue targets. Look for back edges
with a DFS traversal separate from the dominance traversals,
where we count the OpLoopMerge from the header to the continue
target as an edge in the graph.
- It's ok for a loop to have multiple back edges, provided
they are all from the same block, and we call that the latch block.
This may require a clarification/fix in the SPIR-V spec.
- Compute postdominance correctly for infinite loop:
Bias *predecessor* traversal root finding so that you use
a later block in the original list. This ensures that
for certain simple infinite loops in the CFG where neither
block branches to a node without successors, that we'll
compute the loop header as dominating the latch block, and the
latch block as postdominating the loop header.
Fixes dominance calculation when there is a forward arc from an
unreachable block A to a reachable block B. Before this fix, we would
say that B is not dominated by the graph entry node, and instead say
that the immediate dominator of B is the psuedo-entry node of the
augmented CFG.
The fix:
- Dominance is defined in terms of a traversal from the entry block
of the CFG. So the forward DFS should start from the function
entry block, not the pseudo-entry-block.
- When following edges backward during dominance calculations, only go to
nodes that are actually reachable in the forward traversal.
Important: the sense of reachability flips around when computing
post-dominance.
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/297
AssemblyBuilder contains boilplates.
Adds OpName instructions for all added defining instructions.
Adds OpDecorate SpecId for all spec constants added with OpSpecConstant,
OpSpecConstantTrue and OpSpecConstantFalse instructions.
The def-use dominance checker doesn't have enough info to know
that a particular use is in an OpPhi, so skip tracking those uses
for now. Add a TODO to do a proper OpPhi variable-argument check
in the future.
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/286
Ensure the dominance calculation visits all nodes in the CFG.
The successor list of the pseudo-entry node is augmented with
a single node in each cycle that otherwise would not be visited.
Similarly, the predecssors list of the pseduo-exit node is augmented
with the a single node in each cycle that otherwise would not
be visited.
Pulls DepthFirstSearch out so it's accessible outside of the dominator
calculation.
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/279
Add a pass to freeze spec constants to their default values. This pass does
not fold the frozen spec constants and does not handle SpecConstantOp
instructions and SpecConstantComposite instructions.
* Creates an ID class which manages definition and use of IDs
* Moved tracking code from validate.cpp to validate_id.cpp
* Rename and combine SsaPass and ProcessIds into IdPass
* Remove module dependency in Function
