Goals of the PR are:
* to ensure that correct types are applied to virtual registers which
were used as return values in call lowering. A reproducer is attached as
a new test case, before the PR it fails because spirv-val considers
output invalid due to wrong result/operand types in OpPhi's;
* improve type inference by speeding up postprocessing of types: by
limiting iterations by checking what remains to process, and processing
each instruction just once for any number of operands with uncomplete
types;
* improve type inference by more accurate work with uncomplete types
(pass uncomplete property to dependent operands, ensure consistency of
uncomplete-types data structure);
* change processing order and add traversing of PHI nodes when type
inference apply instructions results to specify/update/cast operands
type (fixes an issue with OpPhi's result type mismatch with operand
types).
This PR improves type inference of operand presented by opaque pointers
and aggregate types:
* tries to restore original function return type for aggregate types so
that it's possible to deduce a correct type during emit-intrinsics step
(see llvm/test/CodeGen/SPIRV/SpecConstants/restore-spec-type.ll for the
reproducer of the previously existed issue when spirv-val found a
mismatch between object and ptr types in OpStore due to the incorrect
aggregate types tracing),
* explores untyped pointer operands of store to deduce correct pointee
types,
* creates an extension type to track pointee types from emit-intrinsics
step and further instead of direct and naive usage of TypePointerType
that led previously to crashes due to ban of creation of Value of
TypePointerType type,
* tracks instructions with uncomplete type information and tries to
improve their type info after pass calculated types for all machine
functions (it doesn't traverse a code but rather checks only those
instructions which were tracked as uncompleted),
* address more cases of removing unnecessary bitcasts (see, for example,
changes in test/CodeGen/SPIRV/transcoding/OpGenericCastToPtr.ll where
`CHECK-SPIRV-NEXT` in LIT checks show absence of unneeded bitcasts and
unmangled/mangled versions have proper typing now with equivalent type
info),
* address more cases of well known types or relations between types
within instructions (see, for example, atomic*.ll test cases and
Event-related test cases for improved SPIR-V code generated by the
Backend),
* fix the issue of removing unneeded ptrcast instructions in
pre-legalizer pass that led to creation of new assign-type instructions
with the same argument as source in ptrcast and caused errors in type
inference (the reproducer `complex.ll` test case is added to the PR).
This PR completes implementation of insertion of OpGenericCastToPtr
using builtin functions started by
https://github.com/llvm/llvm-project/pull/95055 by:
* fixing errors in Tablegen definition,
* adding type inference info for `__spirv_GenericCastToPtrExplicit` kind
of wrappers, and
* hardening the test case to check correct translation of
`__spirv_GenericCastToPtrExplicit` kind of wrappers.
This PR implements insertion of OpGenericCastToPtr using builtin
functions (both opencl `to_global|local|private` and `__spirv_`
wrappers), and improves type inference.
