[PATCH] D17946: Add a flag to the LLVMContext to disable name for Value other than GlobalValue

[Justin Bogner via llvm-commits]

Mehdi AMINI <mehdi.amini at apple.com> writes:
> joker.eph updated this revision to Diff 50104.
> joker.eph added a comment.
>
> Rename preserveNames() to preserveNonGlobalValueNames()

preserveNonGlobalValueNames is confusing and awkward. It's much worse
than preserveNames. I'm not convinced preservedNames is bad, but if
you're concerned that it's not precise enough I'd suggest
'preserveAllNames', 'preserveInconsequentialNames', or
'preserveDebugNames'.

>
> http://reviews.llvm.org/D17946
>
> Files:
>   include/llvm/IR/LLVMContext.h
>   lib/AsmParser/LLParser.cpp
>   lib/IR/LLVMContext.cpp
>   lib/IR/LLVMContextImpl.h
>   lib/IR/Value.cpp
>   lib/LTO/LTOCodeGenerator.cpp
>   test/Feature/strip_names.ll
>   tools/llc/llc.cpp
>   tools/opt/opt.cpp
>
> Index: tools/opt/opt.cpp
> ===================================================================
> --- tools/opt/opt.cpp
> +++ tools/opt/opt.cpp
> @@ -196,6 +196,11 @@
>               cl::desc("Run all passes twice, re-using the same pass manager."),
>               cl::init(false), cl::Hidden);
>  
> +static cl::opt<bool> DisableNamedValue(
> +    "disable-named-value",
> +    cl::desc("Strip name from Value (other than GlobalValue)."),
> +    cl::init(false), cl::Hidden);
> +
>  static inline void addPass(legacy::PassManagerBase &PM, Pass *P) {
>    // Add the pass to the pass manager...
>    PM.add(P);
> @@ -345,6 +350,9 @@
>  
>    SMDiagnostic Err;
>  
> +  // Honor "-disable-named-value" command line option
> +  Context.setPreserveNonGlobalValueNames(!DisableNamedValue);
> +
>    // Load the input module...
>    std::unique_ptr<Module> M = parseIRFile(InputFilename, Err, Context);
>  
> Index: tools/llc/llc.cpp
> ===================================================================
> --- tools/llc/llc.cpp
> +++ tools/llc/llc.cpp
> @@ -103,6 +103,11 @@
>                            "manager and verify the result is the same."),
>                   cl::init(false));
>  
> +static cl::opt<bool> DisableNamedValue(
> +    "disable-named-value",
> +    cl::desc("Strip name from Value (other than GlobalValue)."),
> +    cl::init(false), cl::Hidden);
> +
>  static int compileModule(char **, LLVMContext &);
>  
>  static std::unique_ptr<tool_output_file>
> @@ -205,6 +210,9 @@
>  
>    cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n");
>  
> +  // Honor "-disable-named-value" command line option
> +  Context.setPreserveNonGlobalValueNames(!DisableNamedValue);
> +
>    // Compile the module TimeCompilations times to give better compile time
>    // metrics.
>    for (unsigned I = TimeCompilations; I; --I)
> Index: test/Feature/strip_names.ll
> ===================================================================
> --- /dev/null
> +++ test/Feature/strip_names.ll
> @@ -0,0 +1,26 @@
> +; RUN: opt < %s -S | FileCheck %s
> +; RUN: opt < %s  | opt -S -disable-named-value | FileCheck --check-prefix=NONAME %s
> +
> +
> +; CHECK: @GlobalValueName
> +; CHECK: @foo(i32 %in)
> +; CHECK: somelabel:
> +; CHECK:  %GV = load i32, i32* @GlobalValueName
> +; CHECK:  %add = add i32 %in, %GV
> +; CHECK:  ret i32 %add
> +
> +; NONAME: @GlobalValueName
> +; NONAME: @foo(i32)
> +; NONAME-NOT: somelabel:
> +; NONAME:  %2 = load i32, i32* @GlobalValueName
> +; NONAME:  %3 = add i32 %0, %2
> +; NONAME:  ret i32 %3
> +
> + at GlobalValueName = global i32 0
> +
> +define i32 @foo(i32 %in) {
> +somelabel:
> +  %GV = load i32, i32* @GlobalValueName
> +  %add = add i32 %in, %GV
> +  ret i32 %add
> +}
> Index: lib/LTO/LTOCodeGenerator.cpp
> ===================================================================
> --- lib/LTO/LTOCodeGenerator.cpp
> +++ lib/LTO/LTOCodeGenerator.cpp
> @@ -76,6 +76,9 @@
>  LTOCodeGenerator::LTOCodeGenerator(LLVMContext &Context)
>      : Context(&Context), MergedModule(new Module("ld-temp.o", Context)),
>        TheLinker(new Linker(*MergedModule)) {
> +#ifdef NDEBUG
> +  Context.setPreserveNonGlobalValueNames(false);
> +#endif
>    initializeLTOPasses();
>  }
>  
> Index: lib/IR/Value.cpp
> ===================================================================
> --- lib/IR/Value.cpp
> +++ lib/IR/Value.cpp
> @@ -195,6 +195,10 @@
>  }
>  
>  void Value::setNameImpl(const Twine &NewName) {
> +  // Fast-path: LLVMContext can be set to strip out non-GlobalValue names
> +  if (!getContext().preserveNonGlobalValueNames() && !isa<GlobalValue>(this))
> +    return;
> +
>    // Fast path for common IRBuilder case of setName("") when there is no name.
>    if (NewName.isTriviallyEmpty() && !hasName())
>      return;
> Index: lib/IR/LLVMContextImpl.h
> ===================================================================
> --- lib/IR/LLVMContextImpl.h
> +++ lib/IR/LLVMContextImpl.h
> @@ -1034,6 +1034,10 @@
>    /// clients which do use GC.
>    DenseMap<const Function*, std::string> GCNames;
>  
> +  /// Flag to indicate if Value (other than GlobalValue) retains their name or
> +  /// not.
> +  bool PreserveNames = true;
> +
>    LLVMContextImpl(LLVMContext &C);
>    ~LLVMContextImpl();
>  
> Index: lib/IR/LLVMContext.cpp
> ===================================================================
> --- lib/IR/LLVMContext.cpp
> +++ lib/IR/LLVMContext.cpp
> @@ -320,3 +320,9 @@
>  void LLVMContext::deleteGC(const Function &Fn) {
>    pImpl->GCNames.erase(&Fn);
>  }
> +
> +bool LLVMContext::preserveNonGlobalValueNames() { return pImpl->PreserveNames; }
> +
> +void LLVMContext::setPreserveNonGlobalValueNames(bool Preserve) {
> +  pImpl->PreserveNames = Preserve;
> +}
> Index: lib/AsmParser/LLParser.cpp
> ===================================================================
> --- lib/AsmParser/LLParser.cpp
> +++ lib/AsmParser/LLParser.cpp
> @@ -45,6 +45,11 @@
>    // Prime the lexer.
>    Lex.Lex();
>  
> +  if (!Context.preserveNonGlobalValueNames())
> +    return Error(
> +        Lex.getLoc(),
> +        "Can read textual IR with a Context that doesn't support named Values");
> +
>    return ParseTopLevelEntities() ||
>           ValidateEndOfModule();
>  }
> Index: include/llvm/IR/LLVMContext.h
> ===================================================================
> --- include/llvm/IR/LLVMContext.h
> +++ include/llvm/IR/LLVMContext.h
> @@ -103,6 +103,15 @@
>    /// Remove the GC for a function
>    void deleteGC(const Function &Fn);
>  
> +  /// Return true if the Context runtime configuration is set to preserve all
> +  /// value name. When false, only GlobalValue names will be available in the
> +  /// IR.
> +  bool preserveNonGlobalValueNames();
> +
> +  /// Set the Context runtime configuration to preserve all value name (true,
> +  /// default) or only GlobalValue names (false). Clients can use this flag to
> +  /// save memory and runtime, especially in release mode.
> +  void setPreserveNonGlobalValueNames(bool Preserve);
>  
>    typedef void (*InlineAsmDiagHandlerTy)(const SMDiagnostic&, void *Context,
>                                           unsigned LocCookie);