1 files changed, 102 insertions, 0 deletions
diff --git a/llvm/lib/ExecutionEngine/Orc/OrcTargetSupport.cpp b/llvm/lib/ExecutionEngine/Orc/OrcTargetSupport.cpp
new file mode 100644
index 00000000000..4a83a6c0b0c
--- /dev/null
+++ b/llvm/lib/ExecutionEngine/Orc/OrcTargetSupport.cpp
@@ -0,0 +1,102 @@
+#include "llvm/ADT/Triple.h"
+#include "llvm/ExecutionEngine/Orc/IndirectionUtils.h"
+
+#include <array>
+
+using namespace llvm;
+
+namespace {
+
+const char *JITCallbackFuncName = "call_jit_for_lazy_compile";
+const char *JITCallbackIndexLabelPrefix = "jit_resolve_";
+
+std::array<const char *, 12> X86GPRsToSave = {{
+    "rbp", "rbx", "r12", "r13", "r14", "r15", // Callee saved.
+    "rdi", "rsi", "rdx", "rcx", "r8", "r9",   // Int args.
+}};
+
+std::array<const char *, 8> X86XMMsToSave = {{
+    "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6", "xmm7" // FP args
+}};
+
+template <typename OStream> unsigned saveX86Regs(OStream &OS) {
+  for (const auto &GPR : X86GPRsToSave)
+    OS << "  pushq   %" << GPR << "\n";
+
+  OS << "  subq    $" << (16 * X86XMMsToSave.size()) << ", %rsp\n";
+
+  for (unsigned i = 0; i < X86XMMsToSave.size(); ++i)
+    OS << "  movdqu  %" << X86XMMsToSave[i] << ", "
+       << (16 * (X86XMMsToSave.size() - i - 1)) << "(%rsp)\n";
+
+  return (8 * X86GPRsToSave.size()) + (16 * X86XMMsToSave.size());
+}
+
+template <typename OStream> void restoreX86Regs(OStream &OS) {
+  for (unsigned i = 0; i < X86XMMsToSave.size(); ++i)
+    OS << "  movdqu  " << (16 * i) << "(%rsp), %"
+       << X86XMMsToSave[(X86XMMsToSave.size() - i - 1)] << "\n";
+  OS << "  addq    $" << (16 * X86XMMsToSave.size()) << ", %rsp\n";
+
+  for (unsigned i = 0; i < X86GPRsToSave.size(); ++i)
+    OS << "  popq    %" << X86GPRsToSave[X86GPRsToSave.size() - i - 1] << "\n";
+}
+
+uint64_t call_jit_for_fn(JITResolveCallbackHandler *J, uint64_t FuncIdx) {
+  return J->resolve(FuncIdx);
+}
+}
+
+namespace llvm {
+
+std::string getJITResolveCallbackIndexLabel(unsigned I) {
+  std::ostringstream LabelStream;
+  LabelStream << JITCallbackIndexLabelPrefix << I;
+  return LabelStream.str();
+}
+
+void insertX86CallbackAsm(Module &M, JITResolveCallbackHandler &J) {
+  uint64_t CallbackAddr =
+      static_cast<uint64_t>(reinterpret_cast<uintptr_t>(call_jit_for_fn));
+
+  std::ostringstream JITCallbackAsm;
+  Triple TT(M.getTargetTriple());
+
+  if (TT.getOS() == Triple::Darwin)
+    JITCallbackAsm << ".section __TEXT,__text,regular,pure_instructions\n"
+                   << ".align 4, 0x90\n";
+  else
+    JITCallbackAsm << ".text\n"
+                   << ".align 16, 0x90\n";
+
+  JITCallbackAsm << "jit_object_addr:\n"
+                 << "  .quad " << &J << "\n" << JITCallbackFuncName << ":\n";
+
+  uint64_t ReturnAddrOffset = saveX86Regs(JITCallbackAsm);
+
+  // Compute index, load object address, and call JIT.
+  JITCallbackAsm << "  movq    " << ReturnAddrOffset << "(%rsp), %rax\n"
+                 << "  leaq    (jit_indices_start+5)(%rip), %rbx\n"
+                 << "  subq    %rbx, %rax\n"
+                 << "  xorq    %rdx, %rdx\n"
+                 << "  movq    $5, %rbx\n"
+                 << "  divq    %rbx\n"
+                 << "  movq    %rax, %rsi\n"
+                 << "  leaq    jit_object_addr(%rip), %rdi\n"
+                 << "  movq    (%rdi), %rdi\n"
+                 << "  movabsq $" << CallbackAddr << ", %rax\n"
+                 << "  callq   *%rax\n"
+                 << "  movq    %rax, " << ReturnAddrOffset << "(%rsp)\n";
+
+  restoreX86Regs(JITCallbackAsm);
+
+  JITCallbackAsm << "  retq\n"
+                 << "jit_indices_start:\n";
+
+  for (JITResolveCallbackHandler::StubIndex I = 0; I < J.getNumFuncs(); ++I)
+    JITCallbackAsm << getJITResolveCallbackIndexLabel(I) << ":\n"
+                   << "  callq " << JITCallbackFuncName << "\n";
+
+  M.appendModuleInlineAsm(JITCallbackAsm.str());
+}
+}