lib/ExecutionEngine/Orc/OrcTargetSupport.cpp

   1 #include "llvm/ADT/Triple.h"
   2 #include "llvm/ExecutionEngine/Orc/OrcTargetSupport.h"
   3 #include <array>
   4
   5 using namespace llvm::orc;
   6
   7 namespace {
   8
   9 uint64_t executeCompileCallback(JITCompileCallbackManagerBase *JCBM,
  10                                 TargetAddress CallbackID) {
  11   return JCBM->executeCompileCallback(CallbackID);
  12 }
  13
  14 }
  15
  16 namespace llvm {
  17 namespace orc {
  18
  19 const char* OrcX86_64::ResolverBlockName = "orc_resolver_block";
  20
  21 void OrcX86_64::insertResolverBlock(
  22     Module &M, JITCompileCallbackManagerBase &JCBM) {
  23
  24   // Trampoline code-sequence length, used to get trampoline address from return
  25   // address.
  26   const unsigned X86_64_TrampolineLength = 6;
  27
  28   // List of x86-64 GPRs to save.
  29   std::array<const char *, 11> GPRs = {{
  30       "rbx", "r12", "r13", "r14", "r15", // Callee saved (rbp preserved below).
  31       "rdi", "rsi", "rdx", "rcx", "r8", "r9",   // Int args.
  32     }};
  33
  34   // Address of the executeCompileCallback function.
  35   uint64_t CallbackAddr =
  36       static_cast<uint64_t>(
  37         reinterpret_cast<uintptr_t>(executeCompileCallback));
  38
  39   std::ostringstream AsmStream;
  40   Triple TT(M.getTargetTriple());
  41
  42   // Switch to text section.
  43   if (TT.getOS() == Triple::Darwin)
  44     AsmStream << ".section __TEXT,__text,regular,pure_instructions\n"
  45               << ".align 4, 0x90\n";
  46   else
  47     AsmStream << ".text\n"
  48               << ".align 16, 0x90\n";
  49
  50   // Bake in a pointer to the callback manager immediately before the
  51   // start of the resolver function.
  52   AsmStream << "jit_callback_manager_addr:\n"
  53             << "  .quad " << &JCBM << "\n";
  54
  55   // Start the resolver function.
  56   AsmStream << ResolverBlockName << ":\n"
  57             << "  pushq   %rbp\n"
  58             << "  movq    %rsp, %rbp\n";
  59
  60   // Store the GPRs.
  61   for (const auto &GPR : GPRs)
  62     AsmStream << "  pushq   %" << GPR << "\n";
  63
  64   // Store floating-point state with FXSAVE.
  65   AsmStream << "  subq    $512, %rsp\n"
  66             << "  fxsave  (%rsp)\n"
  67
  68   // Load callback manager address, compute trampoline address, call JIT.
  69             << "  lea     jit_callback_manager_addr(%rip), %rdi\n"
  70             << "  movq    (%rdi), %rdi\n"
  71             << "  movq    0x8(%rbp), %rsi\n"
  72             << "  subq    $" << X86_64_TrampolineLength << ", %rsi\n"
  73             << "  movabsq $" << CallbackAddr << ", %rax\n"
  74             << "  callq   *%rax\n"
  75
  76   // Replace the return to the trampoline with the return address of the
  77   // compiled function body.
  78             << "  movq    %rax, 0x8(%rbp)\n"
  79
  80   // Restore the floating point state.
  81             << "  fxrstor (%rsp)\n"
  82             << "  addq    $512, %rsp\n";
  83
  84   for (const auto &GPR : make_range(GPRs.rbegin(), GPRs.rend()))
  85     AsmStream << "  popq    %" << GPR << "\n";
  86
  87   // Restore original RBP and return to compiled function body.
  88   AsmStream << "  popq    %rbp\n"
  89             << "  retq\n";
  90
  91   M.appendModuleInlineAsm(AsmStream.str());
  92 }
  93
  94 OrcX86_64::LabelNameFtor
  95 OrcX86_64::insertCompileCallbackTrampolines(Module &M,
  96                                             TargetAddress ResolverBlockAddr,
  97                                             unsigned NumCalls,
  98                                             unsigned StartIndex) {
  99   const char *ResolverBlockPtrName = "Lorc_resolve_block_addr";
 100
 101   std::ostringstream AsmStream;
 102   Triple TT(M.getTargetTriple());
 103
 104   if (TT.getOS() == Triple::Darwin)
 105     AsmStream << ".section __TEXT,__text,regular,pure_instructions\n"
 106               << ".align 4, 0x90\n";
 107   else
 108     AsmStream << ".text\n"
 109               << ".align 16, 0x90\n";
 110
 111   AsmStream << ResolverBlockPtrName << ":\n"
 112             << "  .quad " << ResolverBlockAddr << "\n";
 113
 114   auto GetLabelName =
 115     [=](unsigned I) {
 116       std::ostringstream LabelStream;
 117       LabelStream << "orc_jcc_" << (StartIndex + I);
 118       return LabelStream.str();
 119   };
 120
 121   for (unsigned I = 0; I < NumCalls; ++I)
 122     AsmStream << GetLabelName(I) << ":\n"
 123               << "  callq *" << ResolverBlockPtrName << "(%rip)\n";
 124
 125   M.appendModuleInlineAsm(AsmStream.str());
 126
 127   return GetLabelName;
 128 }
 129
 130 } // End namespace orc.
 131 } // End namespace llvm.