mlir/examples/minimal-opt/README.md

   1 # Minimal MLIR binaries
   2
   3 This folder contains example of minimal MLIR setups that can showcase the
   4 intended binary footprint of the framework.
   5
   6 - mlir-cat: This includes the Core IR, the builtin dialect, the textual
   7   parser/printer, the support for bytecode serialization.
   8 - mlir-minimal-opt: This adds all the tooling for an mlir-opt tool: the pass
   9   infrastructure and all the instrumentation associated with it.
  10 - mlir-miminal-opt-canonicalize: This add the canonicalizer pass, which pulls in
  11   all the pattern/rewrite machinery, including the PDL compiler and intepreter.
  12
  13 Below are some example measurements taken at the time of the LLVM 17 release,
  14 using clang-14 on a X86 Ubuntu and [bloaty](https://github.com/google/bloaty).
  15
  16 |                                  | Base   | Os     | Oz     | Os LTO | Oz LTO |
  17 | :------------------------------: | ------ | ------ | ------ | ------ | ------ |
  18 | `mlir-cat`                       | 1024KB |  840KB |  885KB |  706KB |  657KB |
  19 | `mlir-minimal-opt`               | 1.62MB | 1.32MB | 1.36MB | 1.17MB | 1.07MB |
  20 | `mlir-minimal-opt-canonicalize`  | 1.83MB | 1.40MB | 1.45MB | 1.25MB | 1.14MB |
  21
  22 Base configuration:
  23
  24 ```
  25 cmake ../llvm/ -G Ninja \
  26    -DCMAKE_BUILD_TYPE=RelWithDebInfo \
  27    -DLLVM_CCACHE_BUILD=ON \
  28    -DLLVM_ENABLE_PROJECTS=mlir \
  29    -DLLVM_BUILD_EXAMPLES=ON \
  30    -DLLVM_TARGETS_TO_BUILD="Native" \
  31    -DCMAKE_C_COMPILER=clang \
  32    -DCMAKE_CXX_COMPILER=clang++ \
  33    -DLLVM_ENABLE_LLD=ON \
  34    -DLLVM_ENABLE_BACKTRACES=OFF \
  35    -DMLIR_ENABLE_PDL_IN_PATTERNMATCH=OFF \
  36    -DCMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO=-Wl,-icf=all
  37 ```
  38
  39 Note: to measure the on-disk size, you need to run `strip bin/mlir-cat` first to
  40 remove all the debug info (which are useful for `bloaty` though).
  41
  42 The optimization level can be tuned with `-Os` or `-Oz`:
  43
  44 - `-DCMAKE_C_FLAGS_RELWITHDEBINFO="-Os -g -DNDEBUG" -DCMAKE_CXX_FLAGS_RELWITHDEBINFO="-Os -g -DNDEBUG"`
  45 - `-DCMAKE_C_FLAGS_RELWITHDEBINFO="-Oz -g -DNDEBUG" -DCMAKE_CXX_FLAGS_RELWITHDEBINFO="-Oz -g -DNDEBUG"`
  46
  47 Finally LTO can also be enabled with `-DLLVM_ENABLE_LTO=FULL`.
  48
  49 Bloaty can provide measurements using:
  50 `bloaty bin/mlir-cat -d compileunits --domain=vm` or
  51 `bloaty bin/mlir-cat -d symbols --demangle=full --domain=vm`