Minimal MLIR binaries

This folder contains example of minimal MLIR setups that can showcase the intended binary footprint of the framework.

mlir-cat: This includes the Core IR, the builtin dialect, the textual parser/printer, the support for bytecode serialization.
mlir-minimal-opt: This adds all the tooling for an mlir-opt tool: the pass infrastructure and all the instrumentation associated with it.
mlir-miminal-opt-canonicalize: This add the canonicalizer pass, which pulls in all the pattern/rewrite machinery, including the PDL compiler and intepreter.

Below are some example measurements taken at the time of the LLVM 17 release, using clang-14 on a X86 Ubuntu and bloaty.

	Base	Os	Oz	Os LTO	Oz LTO
`mlir-cat`	1024KB	840KB	885KB	706KB	657KB
`mlir-minimal-opt`	1.62MB	1.32MB	1.36MB	1.17MB	1.07MB
`mlir-minimal-opt-canonicalize`	1.83MB	1.40MB	1.45MB	1.25MB	1.14MB

Base configuration:

cmake ../llvm/ -G Ninja \
   -DCMAKE_BUILD_TYPE=RelWithDebInfo \
   -DLLVM_CCACHE_BUILD=ON \
   -DLLVM_ENABLE_PROJECTS=mlir \
   -DLLVM_BUILD_EXAMPLES=ON \
   -DLLVM_TARGETS_TO_BUILD="Native" \
   -DCMAKE_C_COMPILER=clang \
   -DCMAKE_CXX_COMPILER=clang++ \
   -DLLVM_ENABLE_LLD=ON \
   -DLLVM_ENABLE_BACKTRACES=OFF \
   -DMLIR_ENABLE_PDL_IN_PATTERNMATCH=OFF \
   -DCMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO=-Wl,-icf=all

Note: to measure the on-disk size, you need to run strip bin/mlir-cat first to remove all the debug info (which are useful for bloaty though).

The optimization level can be tuned with -Os or -Oz:

-DCMAKE_C_FLAGS_RELWITHDEBINFO="-Os -g -DNDEBUG" -DCMAKE_CXX_FLAGS_RELWITHDEBINFO="-Os -g -DNDEBUG"
-DCMAKE_C_FLAGS_RELWITHDEBINFO="-Oz -g -DNDEBUG" -DCMAKE_CXX_FLAGS_RELWITHDEBINFO="-Oz -g -DNDEBUG"

Finally LTO can also be enabled with -DLLVM_ENABLE_LTO=FULL.

Bloaty can provide measurements using: bloaty bin/mlir-cat -d compileunits --domain=vm or bloaty bin/mlir-cat -d symbols --demangle=full --domain=vm