This PR:
* adds support for G_SPLAT_VECTOR generic opcode that may be legally
generated instead of G_BUILD_VECTOR by previous passes of the translator
(see https://github.com/llvm/llvm-project/pull/80378 for the source of
breaking changes);
* improves deduction of types for opaque pointers.
This PR also fixes the following issues:
* if a function has ptr argument(s), two functions that have different
SPIR-V type definitions may get identical LLVM function types and break
agreements of global register and duplicate checker;
* checks for pointer types do not account for TypedPointerType.
Update of tests:
* A test case is added to cover the issue with function ptr parameters.
* The first case, that is support for G_SPLAT_VECTOR generic opcode, is
covered by existing test cases.
* Multiple additional checks by `spirv-val` is added to cover more
possibilities of generation of invalid code.
SPIR-V module typically contains some global entities that were not
global before made it to SPIR-V, e.g. types and constants are not usually
declared globally in LLVM. By design SPIR-V requires such stuff to be declared
once and in the module's global section. Since MIR is not able to represent
such things properly they were generated per-function, and then at the very end
of the backend's pipeline hoisted into some 'meta' function minding possible
duplicates.
New SPIRVDuplicatesTracker keeps mapping of the original LLVM entities such
as types, constant, global variables, etc to their MIR counterparts -
(MachineFunction, Register). Later SPIRVModuleAnalysis (apart from other
thing it's responsible for) performs topological sorting of the
tracker's entries to ensure proper ordering before the hoisting,
and actually performs the hoisting in a duplicates-free manner
by the tracker's nature.
Differential Revision: https://reviews.llvm.org/D128471
