cuobjdump_to_ptxplus — CUDA Binary Disassembly Tool

Bison/Flex Binary Translation PTXPlus SASS Parsing

Architecture

flowchart LR
  subgraph Inputs["Input Files"]
    I1[".ptx file\nPTX instructions"]
    I2[".elf file\nELF binary sections"]
    I3[".sass file\nSASS disassembly"]
  end
  subgraph Parsers["Bison/Flex Parsers"]
    P1["ptx.l / ptx.y\nptx_parse()"]
    P2["elf.l / elf.y\nelf_parse()"]
    P3["sass.l / sass.y\nsass_parse()"]
    P4["header.l / header.y\nHeader directives"]
  end
  subgraph Core["Merge Engine"]
    M1["cuobjdumpInstList\nsetRealTexList()"]
    M2["cuobjdumpInstList\nprintCuobjdumpPtxPlusList()"]
  end
  subgraph Output["Output"]
    O1[".ptxplus file\nPTX + native scheduling"]
  end
  I1 --> P1
  I2 --> P2
  I3 --> P3
  P1 --> M1
  P2 --> M1
  P4 --> M1
  P3 --> M1
  M1 --> M2
  M2 --> O1

Translation Pipeline

flowchart TD
  S1["main() opens 4 files:\nptx, sass, elf, ptxplus_out"] --> S2["elf_parse()\nExtract ELF structure and sections"]
  S2 --> S3["ptx_parse()\nParse PTX instructions and directives\nBuild g_headerList + g_instList"]
  S3 --> S4["setRealTexList()\nCopy texture refs from header to inst list"]
  S4 --> S5["sass_parse()\nParse SASS instructions and schedules"]
  S5 --> S6["printHeaderInstList()\nEmit //HEADER section"]
  S6 --> S7["printCuobjdumpPtxPlusList()\nMerge PTX ops + SASS scheduling"]
  S7 --> S8["Output: PTXPlus file\nPTX with native instruction ordering"]

Key Classes & Structures

Key Functions

Lex/Yacc Grammar Structure

Module Interactions

Code Snippets

Main Driver — cuobjdump_to_ptxplus.cc

// cuobjdump_to_ptxplus.cc — main translation driver
cuobjdumpInstList *g_instList = new cuobjdumpInstList();
cuobjdumpInstList *g_headerList = new cuobjdumpInstList();

int main(int argc, char* argv[]) {
    // Usage: cuobjdump_to_ptxplus ptx sass elf ptxplus_out
    sass_in  = fopen(argv[2], "r");
    ptx_in   = fopen(argv[1], "r");
    elf_in   = fopen(argv[3], "r");
    ptxplus_out = fopen(argv[4], "w");

    elf_parse();    // Parse ELF structure
    ptx_parse();    // Parse PTX → g_instList + g_headerList
    assert(!g_error_detected);

    // Map texture references from PTX header
    g_instList->setRealTexList(g_headerList->getRealTexList());

    sass_parse();   // Parse SASS + merge scheduling

    // Emit PTXPlus output
    output("//HEADER\n");
    g_headerList->printHeaderInstList();
    output("//END HEADER\n\n\n");
    output("//INSTRUCTIONS\n");
    g_instList->printCuobjdumpPtxPlusList(g_headerList);
    output("//END INSTRUCTIONS\n");
    return 0;
}

cuobjdumpInst — Instruction Data Structure

// cuobjdumpInst.h — single instruction representation
class cuobjdumpInst {
protected:
    std::string m_label;                      // instruction label
    std::list<std::string>* m_predicate;      // predicate register
    std::string m_base;                       // mnemonic (add, mov, ld, etc.)
    std::list<std::string>* m_baseModifiers;  // .rn, .ftz, .sat, etc.
    std::list<std::string>* m_typeModifiers;  // .f32, .u64, .s16, etc.
    std::list<std::string>* m_operands;       // destination + sources
    std::list<std::string>* m_predicateModifiers;
public:
    void setBase(const char* mnemonic);
    void addOperand(const char* operand);
    void printCuobjdumpPtxPlus();  // emit in PTXPlus format
};

Usage

# Manual invocation (normally called automatically by the simulator)
cuobjdump_to_ptxplus kernel.ptx kernel.sass kernel.elf output.ptxplus

# Enable in simulator config
-gpgpu_ptx_convert_to_ptxplus 1

# The simulator invokes this tool during __cudaRegisterFatBinary()
# when CUDA >= 4.0 and the config knob is enabled

Directory Map

cuobjdump_to_ptxplus/
├── cuobjdump_to_ptxplus.cc  ← 143 lines — main driver: open files, run parsers, emit output
├── cuobjdumpInst.h          ← cuobjdumpInst class declaration
├── cuobjdumpInst.cc         ← cuobjdumpInst methods: print, format, accessors
├── cuobjdumpInstList.h      ← cuobjdumpInstList class declaration
├── cuobjdumpInstList.cc     ← Container methods: merge, emit, texture mapping
├── ptx.l                    ← Flex lexer for PTX instruction tokenization
├── ptx.y                    ← Bison parser for PTX grammar
├── ptx_parser.h             ← Shared PTX parser declarations
├── elf.l                    ← Flex lexer for ELF section format
├── elf.y                    ← Bison parser for ELF binary structure
├── sass.l                   ← Flex lexer for SASS native disassembly
├── sass.y                   ← Bison parser for SASS instructions
├── header.l                 ← Flex lexer for PTX header directives
├── header.y                 ← Bison parser for header (.version, .target)
└── Makefile                 ← Builds cuobjdump_to_ptxplus executable

Glossary