Replace uses of getAllocatedType() in PromoteMemoryToRegister.cpp with
type tracking from actual loads and stores. This makes the promotion
logic more semantic - it now checks that all loads/stores use a
consistent type rather than requiring them to match the alloca's
declared type.
Changes:
- isAllocaPromotable() now tracks the first load/store type seen and
ensures all subsequent accesses use the same type
- AllocaInfo gains a ValueType field populated during AnalyzeAlloca()
- PromoteMem2Reg tracks AllocaValueTypes alongside other per-alloca info
- PHI nodes and UndefValues are created using the tracked type
This is semantically more permissive - an alloca declared as i64 but
only accessed as i32 is now promotable. This is correct because the
alloca is just a blob of memory; what matters for Mem2Reg is consistent
access patterns.
Test changes:
- asan-stack-safety.ll: Changed loads/stores to volatile to prevent
promotion while preserving ASAN stack safety analysis behavior
- SPIRV pointer tests (array-skips-gep.ll, load-struct.ll,
store-struct.ll, store-to-array-first-element.ll): Added escape calls to
prevent alloca promotion, as these tests verify SPIRV backend handling
of Function-storage-class pointers
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
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.
OpenCL is allowed to cast pointers, meaning they can resolve some type
mismatches this way. In logical SPIR-V, those are restricted. This new
pass legalizes such pointer cast when targeting logical SPIR-V.
For now, this pass supports 3 cases we witnessed:
- loading a vec3 from a vec4*.
- loading a scalar from a vec*.
- loading the 1st element of an array.
---------
Co-authored-by: Steven Perron <stevenperron@google.com>
