lib/ExecutionEngine/Orc/OrcTargetSupport.cpp

   1 #include "llvm/ADT/Triple.h"
   2 #include "llvm/ExecutionEngine/Orc/IndirectionUtils.h"
   3
   4 #include <array>
   5
   6 using namespace llvm;
   7
   8 namespace {
   9
  10 const char *JITCallbackFuncName = "call_jit_for_lazy_compile";
  11 const char *JITCallbackIndexLabelPrefix = "jit_resolve_";
  12
  13 std::array<const char *, 12> X86GPRsToSave = {{
  14     "rbp", "rbx", "r12", "r13", "r14", "r15", // Callee saved.
  15     "rdi", "rsi", "rdx", "rcx", "r8", "r9",   // Int args.
  16 }};
  17
  18 std::array<const char *, 8> X86XMMsToSave = {{
  19     "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6", "xmm7" // FP args
  20 }};
  21
  22 template <typename OStream> unsigned saveX86Regs(OStream &OS) {
  23   for (const auto &GPR : X86GPRsToSave)
  24     OS << "  pushq   %" << GPR << "\n";
  25
  26   OS << "  subq    $" << (16 * X86XMMsToSave.size()) << ", %rsp\n";
  27
  28   for (unsigned i = 0; i < X86XMMsToSave.size(); ++i)
  29     OS << "  movdqu  %" << X86XMMsToSave[i] << ", "
  30        << (16 * (X86XMMsToSave.size() - i - 1)) << "(%rsp)\n";
  31
  32   return (8 * X86GPRsToSave.size()) + (16 * X86XMMsToSave.size());
  33 }
  34
  35 template <typename OStream> void restoreX86Regs(OStream &OS) {
  36   for (unsigned i = 0; i < X86XMMsToSave.size(); ++i)
  37     OS << "  movdqu  " << (16 * i) << "(%rsp), %"
  38        << X86XMMsToSave[(X86XMMsToSave.size() - i - 1)] << "\n";
  39   OS << "  addq    $" << (16 * X86XMMsToSave.size()) << ", %rsp\n";
  40
  41   for (unsigned i = 0; i < X86GPRsToSave.size(); ++i)
  42     OS << "  popq    %" << X86GPRsToSave[X86GPRsToSave.size() - i - 1] << "\n";
  43 }
  44
  45 uint64_t call_jit_for_fn(JITResolveCallbackHandler *J, uint64_t FuncIdx) {
  46   return J->resolve(FuncIdx);
  47 }
  48 }
  49
  50 namespace llvm {
  51
  52 std::string getJITResolveCallbackIndexLabel(unsigned I) {
  53   std::ostringstream LabelStream;
  54   LabelStream << JITCallbackIndexLabelPrefix << I;
  55   return LabelStream.str();
  56 }
  57
  58 void insertX86CallbackAsm(Module &M, JITResolveCallbackHandler &J) {
  59   uint64_t CallbackAddr =
  60       static_cast<uint64_t>(reinterpret_cast<uintptr_t>(call_jit_for_fn));
  61
  62   std::ostringstream JITCallbackAsm;
  63   Triple TT(M.getTargetTriple());
  64
  65   if (TT.getOS() == Triple::Darwin)
  66     JITCallbackAsm << ".section __TEXT,__text,regular,pure_instructions\n"
  67                    << ".align 4, 0x90\n";
  68   else
  69     JITCallbackAsm << ".text\n"
  70                    << ".align 16, 0x90\n";
  71
  72   JITCallbackAsm << "jit_object_addr:\n"
  73                  << "  .quad " << &J << "\n" << JITCallbackFuncName << ":\n";
  74
  75   uint64_t ReturnAddrOffset = saveX86Regs(JITCallbackAsm);
  76
  77   // Compute index, load object address, and call JIT.
  78   JITCallbackAsm << "  movq    " << ReturnAddrOffset << "(%rsp), %rax\n"
  79                  << "  leaq    (jit_indices_start+5)(%rip), %rbx\n"
  80                  << "  subq    %rbx, %rax\n"
  81                  << "  xorq    %rdx, %rdx\n"
  82                  << "  movq    $5, %rbx\n"
  83                  << "  divq    %rbx\n"
  84                  << "  movq    %rax, %rsi\n"
  85                  << "  leaq    jit_object_addr(%rip), %rdi\n"
  86                  << "  movq    (%rdi), %rdi\n"
  87                  << "  movabsq $" << CallbackAddr << ", %rax\n"
  88                  << "  callq   *%rax\n"
  89                  << "  movq    %rax, " << ReturnAddrOffset << "(%rsp)\n";
  90
  91   restoreX86Regs(JITCallbackAsm);
  92
  93   JITCallbackAsm << "  retq\n"
  94                  << "jit_indices_start:\n";
  95
  96   for (JITResolveCallbackHandler::StubIndex I = 0; I < J.getNumFuncs(); ++I)
  97     JITCallbackAsm << getJITResolveCallbackIndexLabel(I) << ":\n"
  98                    << "  callq " << JITCallbackFuncName << "\n";
  99
 100   M.appendModuleInlineAsm(JITCallbackAsm.str());
 101 }
 102 }