To make the decoration manger available everywhere, and to reduce the
number of times it needs to be build, I add one the IRContext.
As the same time, I move code that modifies decoration instruction into
the IRContext from mempass and the decoration manager. This will make
it easier to keep everything up to date.
This should take care of issue #928.
This is the first step in replacing the std::vector of Instruction
pointers to using and intrusive linked list.
To this end, we created the InstructionList class. It inherites from
the IntrusiveList class, but add the extra concept of ownership. An
InstructionList owns the instruction that are in it. This is to be
consistent with the current ownership rules where the vector owns the
instruction that are in it.
The other larger change is that the inst_ member of the BasicBlock class
was changed to using the InstructionList class.
Added test for the InsertBefore functions, and making sure that the
InstructionList destructor will delete the elements that it contains.
I've also add extra comments to explain ownership a little better.
- Adds a new pass CFGCleanupPass. This serves as an umbrella pass to
remove unnecessary cruft from a CFG.
- Currently, the only cleanup operation done is the removal of
unreachable basic blocks.
- Adds unit tests.
- Adds a flag to spirvopt to execute the pass (--cfg-cleanup).
Also:
- Add const forms of ForEachInst
- Rewrite Module::ToBinary in terms of ForEachInst
- Add Instruction::ToBinaryWithoutAttachedDebugInsts
- Delete the ToBinary method on Function, BasicBlock, and Instruction
since it can now be implemented with ForEachInst in a less confusing
way, e.g. without recursion.
- Preserve debug line instructions on OpFunctionEnd (and store that
instruction as a unique-pointer, for regularity).