MaskRay added a comment. In D104556#2836900 <https://reviews.llvm.org/D104556#2836900>, @rnk wrote:
> In D104556#2831787 <https://reviews.llvm.org/D104556#2831787>, @MaskRay wrote: > >> Hmm, IMGREL (`IMAGE_REL_AMD64_ADDR32NB`) looks useful and is an alternative >> solution to PC-relative relocations in ELF / relocation subtraction in >> Mach-O. >> But leveraging it seems to need more code in the runtime and will make COFF >> vs non-COFF different in IR, runtime, and llvm-profdata.... > > We can go forward with what we have, but the `signextIfWin64` helper is > pretty subtle. In some ways, I think adding `__ImageBase` is clearer: > > #ifdef _WIN32 > extern "C" char __ImageBase; > #endif > uintptr_t rebaseRelativePtr(void *D, void *P) { > #ifdef _WIN32 > return (uintptr_t)&__ImageBase + (uintptr_t)P; > #else > return (uintptr_t)D + (uintptr_t)P; > #endif > } > > It's not quite this easy, and the instrumentation side changes have to > basically copy or refactor this code: > https://github.com/llvm/llvm-project/blob/main/clang/lib/CodeGen/MicrosoftCXXABI.cpp#L548 > > We aren't worried about profraw format compatibility on Windows, so I think > we can change this later at any time if we like. I think you mean that `INSTR_PROF_RAW_HEADER(uint64_t, CountersDelta, (uintptr_t)CountersBegin - (uintptr_t)DataBegin)` (in InstrProfiling.cpp, so used by both -fprofile-generate and -fprofile-instr-generate) needs to adopt the scheme in https://github.com/llvm/llvm-project/blob/main/clang/lib/CodeGen/MicrosoftCXXABI.cpp#L548 Yes, seems quite a bit of complexity. Is it possible to ask MSVC to add the 64-bit `IMAGE_REL_AMD64_REL64` and `IMAGE_REL_ARM64_REL64`? Newer compiler metadata techniques can benefit from using the same mechanism for all three major binary formats (PE-COFF/ELF/Mach-O). Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D104556/new/ https://reviews.llvm.org/D104556 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
