README.md

---
pretty_name: "ComBack++"
language: 
  - code
pipeline_tag: Compiler Backend
tags:
  - C++/TableGen/Machine Description Code
  - Compiler Backend
license: "cc-by-4.0"
# configs:
# - config_name: Statement-Level Completion
#   data_files :
#     - split: train
#       path: Code_Completion/statement_level/train*
#     - split: validation
#       path: Code_Completion/statement_level/valid*
#     - split: test
#       path: Code_Completion/statement_level/test*
# - config_name: Next-Statement Suggestion
#   data_files :
#     - split: train
#       path: Code_Completion/next_statement/train*
#     - split: validation
#       path: Code_Completion/next_statement/valid*
#     - split: test
#       path: Code_Completion/next_statement/test*
# - config_name: Code Generation
#   data_files :
#     - split: train
#       path: Code_Generation/train*
#     - split: validation
#       path: Code_Generation/valid*
#     - split: test
#       path: Code_Generation/test*
---


# ComBack++: A Multi-Language Dataset Providing End-to-End Support for Compiler Backend Development

ComBack++ is a large-scale, multi-platform and multi-language compiler backend code dataset. It is sourced from GCC and LLVM backends corresponding to 183 target platforms.
  
## Dataset Information

- Source Data
  - GCC

  | Category | Target Platform | C++ Function | C++ KLoC | Machine Description KLoC |
  | ---- | ---- | ---- | ---- | ---- |
  | CPU | 30 | 56,211  | 858.2 | 228.5 |
  | MPU | 35 | 8,713   | 243.8 | 87.1 |
  | GPU | 2 | 731  | 12.7 | 3.0 |
  | VLIW | 5 | 1,323  | 32.8 | 17.8 |
  | DSP | 4 | 542  | 17.2 | 6.1 |
  | Virtual | 5 | 558 | 10.5 | 0.1 |
  | **SUM** | **81** | **68,078**  | **1175.2** | **342.6** |


  - LLVM

  | Category | Target Platform | C++ Function | C++ KLoC | TableGen KLoC |
  | ---- | ---- | ---- | ---- | ---- |
  | CPU | 43 | 97,972  | 3,768.4 | 1,157.7 |
  | MPU | 30 | 12,552   | 190.7  | 24.8 |
  | GPU | 5 | 28,267  | 886.8 | 168.5 |
  | VLIW | 5 | 2,386  | 27.4 | 0.8 |
  | DSP | 7 | 11,584  | 296.8 | 129.4 |
  | Virtual | 12 |  10,538  | 199.4 | 12.9 |
  | **SUM** | **102** | **163,299**  | **5,369.5** | **1,494.1** |


- Tasks
  - Statement-Level Completion: complete current statement.
  ```c++
  //Inputs:
  ...
  adjustReg(MBB,LastFrameDestroy, DL, SPReg, FPReg, -StackSize+RVFI->getVarArgsSaveSize() 
  //Ground Truth:
  MachineInstr::FrameDestroy);
  ```

  - Next-Statement Suggestion: predict the next statement.

   ```c++
  //Inputs:
  ...
  maxCallFrameSize = (maxCallFrameSize + AlignMask) & ~AlignMask;
  //Ground Truth:
  MFI -> setMaxCallFrameSize(maxCallFrameSize);
  ```


  - Code Generation: generate a function template with function description in natrual language.

   ```c++
  //Inputs:
  getPointerRegClass: Returns a TargetRegisterClass used for pointer values.
  //Ground Truth:
  TargetRegisterClass *RegisterInfo::getPointerRegClass(MachineFunction &MF ,unsigned Kind) {
      return Subtarget.is64Bit() ? <ISA_LIT> : <ISA_LIT>;
  }
  ```

  - Program Repair: automatically fixing bugs at identified locations.

   ```c++
  //Inputs:
  int64_t Imm; <BUGS> MCExpr::VariantKind VK; <BUGE> ...
  //Ground Truth:
  <FIXS> MCExpr::VariantKind VK = MCExpr::VK_None; <FIXE>
  ```

## Organization



- `./*.jsonl`: **Take data of RISC-V,ARC,NVPTX both in GCC and LLVM as test set, split train/valid set in the ratio of 90%:10% of other targets excluding RI5CY(RI5CY is custmoized based on RISCV)**



  | Task | Programming Language | Train | Valid | Test |
  |----------------------------  |----------------------  |------------------  |----------------  |---------------  |
  | Statement-Level Completion | C++ | 149,368 (16.41M) | 16,480 (1.84M) | 7,897 (0.82M) |
  | Statement-Level Completion | TableGen/MD | 120,460 (4.46M) | 13,295 (0.50M) | 7,090 (0.25M) |
  | Next-Statement Suggestion | C++ | 137,155 (20.55M) | 15,218 (2.32M) | 8,109 (1.09M) |
  | Next-Statement Suggestion | TableGen/MD | 124,528 (6.71M) | 14,009 (0.76M) | 2,726 (0.14M) |
  | Code Generation | C++ | 37,805 (10.69M) | 4,137 (1.16M) | 2,944 (0.73M) |
  | Program Repair | C++ | 40,578 (4.33M) | 4,539 (0.48M) | 2,623 (0.29M) |
  | Program Repair | TableGen/MD | 25,983 (2.95M) | 2,975 (0.33M) | 1,814 (0.24M) |



## Citation
```
@article{zhong2025bepilot,
author = {Zhong, Ming and Sun, Xin and Lv, Fang and Wang, Lulin and Geng, Hongna and Qiu, Lei and Cui, Huimin and Feng, Xiaobing},
title = {BePilot: An AI Programming Assistant for Compiler Backend Development},
year = {2025},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
issn = {1049-331X},
url = {https://doi.org/10.1145/3764585},
doi = {10.1145/3764585},
note = {Just Accepted},
journal = {ACM Trans. Softw. Eng. Methodol.}
}
```