Refactor of the llvm-tblgen source into:
- a "Basic" library, which contains the bare minimum utilities to build
`llvm-min-tablegen`
- a "Common" library which contains all of the helpers for TableGen
backends. Such helpers can be shared by more than one backend, and even
unit tested (e.g. CodeExpander is, maybe we can add more over time)
Fixes#80647
The output for the `checkPredicate` function was depending on a
`std::map` iteration that was non-deterministic from run to run, because
the keys were pointer values.
Make a change so that the keys are `StringRef`s so the ordering is
stable.
This patch is a straightfoward change based on the design in #77202.
It does not have any effect since we haven't supported compressing ND
to non-ND in X86CompressEVEX.cpp.
BTW, we relax the condition for EVEX compression from
ST.hasAVX512() to ST.hasEGPR() || ST.hasAVX512(). It does not have any
effect now b/c no APX instruction is in the EVEX compression table so
far.
This patch is to extract NFC in #77065 into a separate commit.
1. Simplify getValueFromBitsInit about cast and return type
2. Remove out-of-date comments and allow memory ops in function
object `IsMatch` so that we can reuse it for EVEX2Legacy compression.
This patch is to extract NFC in #77065 into a separate commit.
Remove these two classes and put all the entries in X86 EVEX compression tables
that need special handling in .def file.
PR #77065 tries to add entries that need special handling for APX in
.def file. Compared to setting fields in td files, that method looks
cleaner. This patch is to unify the addition of manual entries.
RFC: https://discourse.llvm.org/t/rfc-design-for-apx-feature-egpr-and-ndd-support/73031
APX introduces EGPR, NDD and NF instructions. In addition to compressing
EVEX encoded AVX512 instructions into VEX encoding, we also have several
more possible optimizations.
a. Promoted instruction (EVEX space) -> pre-promotion instruction (legacy space)
b. NDD (EVEX space) -> non-NDD (legacy space)
c. NF_ND (EVEX space) -> NF (EVEX space)
The first two types of compression can usually reduce code size, while
the third type of compression can help hardware decode although the
instruction length remains unchanged.
So we do the renaming for the upcoming APX optimizations.
BTW, I clang-format the code in X86CompressEVEX.cpp,
X86CompressEVEXTablesEmitter.cpp.
This patch also extracts the NFC in #77065 into a separate commit.
