This PR is to thoroughly rework duplicate tracker implementation and
tracking of IR entities and types. These are legacy parts of the project
resulting in an extremely bloated intermediate representation and
computational delays due to inefficient data flow and structure choices.
Main results of the rework:
1) Improved compile-time performance. The reference binary LLVM IR used
to measure speed gains in
https://github.com/llvm/llvm-project/pull/120415 shows ~x5 speed up also
after this PR. The timing before this PR is ~42s and after this PR it's
~7.5s. In total this PR and the previous overhaul of the module analysis
in https://github.com/llvm/llvm-project/pull/120415 results in ~x25
speed improvement.
```
$ time llc -O0 -mtriple=spirv64v1.6-unknown-unknown _group_barrier_phi.bc -o 1 --filetype=obj
real 0m7.545s
user 0m6.685s
sys 0m0.859s
```
2) Less bloated intermediate representation of internal translation
steps. Elimination of `spv_track_constant` intrinsic usage for scalar
constants, rework of `spv_assign_name`, removal of the gMIR `GET_XXX`
pseudo code and a smaller number of generated `ASSIGN_TYPE` pseudo codes
substantially decrease volume of data generated during translation.
3) Simpler code and easier maintenance. The duplicate tracker
implementation is simplified, as well as other features.
4) Numerous fixes of issues and logical flaws in different passes. The
main achievement is rework of the duplicate tracker itself that had
never guaranteed a correct caching of LLVM IR entities, rarely and
randomly returning stale/incorrect records (like, remove an instruction
from gMIR but still refer to it). Other fixes comprise consistent
generation of OpConstantNull, assigning types to newly created
registers, creation of integer/bool types, and other minor fixes.
5) Numerous fixes of LIT tests: mainly CHECK-DAG to properly reflect
SPIR-V spec guarantees, `{{$}}` at the end of constants to avoid
matching of substrings, and XFAILS for `SPV_INTEL_long_composites` test
cases, because the feature is not completed in full yet and doesn't
generate a requested by the extension sequence of instructions.
6) New test cases are added.
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.
This pull request aims to remove any dependency on OpenCL/SPIR-V type
information in LLVM IR metadata. While, using metadata might simplify
and prettify the resulting SPIR-V output (and restore some of the
information missed in the transformation to opaque pointers), the
overall methodology for resolving kernel parameter types is highly
inefficient.
The high-level strategy is to assign kernel parameter types in this order:
1. Resolving the types using builtin function calls as mangled names
must contain type information or by looking up builtin definition in
SPIRVBuiltins.td. Then:
- Assigning the type temporarily using an intrinsic and later setting
the right SPIR-V type in SPIRVGlobalRegistry after IRTranslation
- Inserting a bitcast
2. Defaulting to LLVM IR types (in case of pointers the generic i8*
type or types from byval/byref attributes)
In case of type incompatibility (e.g. parameter defined initially as
sampler_t and later used as image_t) the error will be found early on
before IRTranslation (in the SPIRVEmitIntrinsics pass).
