1 files changed, 138 insertions, 0 deletions
diff --git a/contrib/llvm/lib/ExecutionEngine/Orc/OrcTargetSupport.cpp b/contrib/llvm/lib/ExecutionEngine/Orc/OrcTargetSupport.cpp
new file mode 100644
index 0000000..258868a
--- /dev/null
+++ b/contrib/llvm/lib/ExecutionEngine/Orc/OrcTargetSupport.cpp
@@ -0,0 +1,138 @@
+#include "llvm/ADT/Triple.h"
+#include "llvm/ExecutionEngine/Orc/OrcTargetSupport.h"
+#include <array>
+
+using namespace llvm::orc;
+
+namespace {
+
+uint64_t executeCompileCallback(JITCompileCallbackManagerBase *JCBM,
+                                TargetAddress CallbackID) {
+  return JCBM->executeCompileCallback(CallbackID);
+}
+
+}
+
+namespace llvm {
+namespace orc {
+
+const char* OrcX86_64::ResolverBlockName = "orc_resolver_block";
+
+void OrcX86_64::insertResolverBlock(
+    Module &M, JITCompileCallbackManagerBase &JCBM) {
+
+  // Trampoline code-sequence length, used to get trampoline address from return
+  // address.
+  const unsigned X86_64_TrampolineLength = 6;
+
+  // List of x86-64 GPRs to save. Note - RBP saved separately below.
+  std::array<const char *, 14> GPRs = {{
+      "rax", "rbx", "rcx", "rdx",
+      "rsi", "rdi", "r8", "r9",
+      "r10", "r11", "r12", "r13",
+      "r14", "r15"
+    }};
+
+  // Address of the executeCompileCallback function.
+  uint64_t CallbackAddr =
+      static_cast<uint64_t>(
+        reinterpret_cast<uintptr_t>(executeCompileCallback));
+
+  std::ostringstream AsmStream;
+  Triple TT(M.getTargetTriple());
+
+  // Switch to text section.
+  if (TT.getOS() == Triple::Darwin)
+    AsmStream << ".section __TEXT,__text,regular,pure_instructions\n"
+              << ".align 4, 0x90\n";
+  else
+    AsmStream << ".text\n"
+              << ".align 16, 0x90\n";
+
+  // Bake in a pointer to the callback manager immediately before the
+  // start of the resolver function.
+  AsmStream << "jit_callback_manager_addr:\n"
+            << "  .quad " << &JCBM << "\n";
+
+  // Start the resolver function.
+  AsmStream << ResolverBlockName << ":\n"
+            << "  pushq     %rbp\n"
+            << "  movq      %rsp, %rbp\n";
+
+  // Store the GPRs.
+  for (const auto &GPR : GPRs)
+    AsmStream << "  pushq     %" << GPR << "\n";
+
+  // Store floating-point state with FXSAVE.
+  // Note: We need to keep the stack 16-byte aligned, so if we've emitted an odd
+  //       number of 64-bit pushes so far (GPRs.size() plus 1 for RBP) then add
+  //       an extra 64 bits of padding to the FXSave area.
+  unsigned Padding = (GPRs.size() + 1) % 2 ? 8 : 0;
+  unsigned FXSaveSize = 512 + Padding;
+  AsmStream << "  subq      $" << FXSaveSize << ", %rsp\n"
+            << "  fxsave64  (%rsp)\n"
+
+  // Load callback manager address, compute trampoline address, call JIT.
+            << "  lea       jit_callback_manager_addr(%rip), %rdi\n"
+            << "  movq      (%rdi), %rdi\n"
+            << "  movq      0x8(%rbp), %rsi\n"
+            << "  subq      $" << X86_64_TrampolineLength << ", %rsi\n"
+            << "  movabsq   $" << CallbackAddr << ", %rax\n"
+            << "  callq     *%rax\n"
+
+  // Replace the return to the trampoline with the return address of the
+  // compiled function body.
+            << "  movq      %rax, 0x8(%rbp)\n"
+
+  // Restore the floating point state.
+            << "  fxrstor64 (%rsp)\n"
+            << "  addq      $" << FXSaveSize << ", %rsp\n";
+
+  for (const auto &GPR : make_range(GPRs.rbegin(), GPRs.rend()))
+    AsmStream << "  popq      %" << GPR << "\n";
+
+  // Restore original RBP and return to compiled function body.
+  AsmStream << "  popq      %rbp\n"
+            << "  retq\n";
+
+  M.appendModuleInlineAsm(AsmStream.str());
+}
+
+OrcX86_64::LabelNameFtor
+OrcX86_64::insertCompileCallbackTrampolines(Module &M,
+                                            TargetAddress ResolverBlockAddr,
+                                            unsigned NumCalls,
+                                            unsigned StartIndex) {
+  const char *ResolverBlockPtrName = "Lorc_resolve_block_addr";
+
+  std::ostringstream AsmStream;
+  Triple TT(M.getTargetTriple());
+
+  if (TT.getOS() == Triple::Darwin)
+    AsmStream << ".section __TEXT,__text,regular,pure_instructions\n"
+              << ".align 4, 0x90\n";
+  else
+    AsmStream << ".text\n"
+              << ".align 16, 0x90\n";
+
+  AsmStream << ResolverBlockPtrName << ":\n"
+            << "  .quad " << ResolverBlockAddr << "\n";
+
+  auto GetLabelName =
+    [=](unsigned I) {
+      std::ostringstream LabelStream;
+      LabelStream << "orc_jcc_" << (StartIndex + I);
+      return LabelStream.str();
+  };
+
+  for (unsigned I = 0; I < NumCalls; ++I)
+    AsmStream << GetLabelName(I) << ":\n"
+              << "  callq *" << ResolverBlockPtrName << "(%rip)\n";
+
+  M.appendModuleInlineAsm(AsmStream.str());
+
+  return GetLabelName;
+}
+
+} // End namespace orc.
+} // End namespace llvm.