1 files changed, 144 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/X86/X86AsmPrinter.h b/contrib/llvm/lib/Target/X86/X86AsmPrinter.h
new file mode 100644
index 000000000000..d7c3b74d3efb
--- /dev/null
+++ b/contrib/llvm/lib/Target/X86/X86AsmPrinter.h
@@ -0,0 +1,144 @@
+//===-- X86AsmPrinter.h - X86 implementation of AsmPrinter ------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_X86_X86ASMPRINTER_H
+#define LLVM_LIB_TARGET_X86_X86ASMPRINTER_H
+
+#include "X86Subtarget.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/FaultMaps.h"
+#include "llvm/CodeGen/StackMaps.h"
+#include "llvm/Target/TargetMachine.h"
+
+// Implemented in X86MCInstLower.cpp
+namespace {
+  class X86MCInstLower;
+}
+
+namespace llvm {
+class MCStreamer;
+class MCSymbol;
+
+class LLVM_LIBRARY_VISIBILITY X86AsmPrinter : public AsmPrinter {
+  const X86Subtarget *Subtarget;
+  StackMaps SM;
+  FaultMaps FM;
+  std::unique_ptr<MCCodeEmitter> CodeEmitter;
+
+  // This utility class tracks the length of a stackmap instruction's 'shadow'.
+  // It is used by the X86AsmPrinter to ensure that the stackmap shadow
+  // invariants (i.e. no other stackmaps, patchpoints, or control flow within
+  // the shadow) are met, while outputting a minimal number of NOPs for padding.
+  //
+  // To minimise the number of NOPs used, the shadow tracker counts the number
+  // of instruction bytes output since the last stackmap. Only if there are too
+  // few instruction bytes to cover the shadow are NOPs used for padding.
+  class StackMapShadowTracker {
+  public:
+    void startFunction(MachineFunction &MF) {
+      this->MF = &MF;
+    }
+    void count(MCInst &Inst, const MCSubtargetInfo &STI,
+               MCCodeEmitter *CodeEmitter);
+
+    // Called to signal the start of a shadow of RequiredSize bytes.
+    void reset(unsigned RequiredSize) {
+      RequiredShadowSize = RequiredSize;
+      CurrentShadowSize = 0;
+      InShadow = true;
+    }
+
+    // Called before every stackmap/patchpoint, and at the end of basic blocks,
+    // to emit any necessary padding-NOPs.
+    void emitShadowPadding(MCStreamer &OutStreamer, const MCSubtargetInfo &STI);
+  private:
+    const MachineFunction *MF;
+    bool InShadow = false;
+
+    // RequiredShadowSize holds the length of the shadow specified in the most
+    // recently encountered STACKMAP instruction.
+    // CurrentShadowSize counts the number of bytes encoded since the most
+    // recently encountered STACKMAP, stopping when that number is greater than
+    // or equal to RequiredShadowSize.
+    unsigned RequiredShadowSize = 0, CurrentShadowSize = 0;
+  };
+
+  StackMapShadowTracker SMShadowTracker;
+
+  // All instructions emitted by the X86AsmPrinter should use this helper
+  // method.
+  //
+  // This helper function invokes the SMShadowTracker on each instruction before
+  // outputting it to the OutStream. This allows the shadow tracker to minimise
+  // the number of NOPs used for stackmap padding.
+  void EmitAndCountInstruction(MCInst &Inst);
+  void LowerSTACKMAP(const MachineInstr &MI);
+  void LowerPATCHPOINT(const MachineInstr &MI, X86MCInstLower &MCIL);
+  void LowerSTATEPOINT(const MachineInstr &MI, X86MCInstLower &MCIL);
+  void LowerFAULTING_OP(const MachineInstr &MI, X86MCInstLower &MCIL);
+  void LowerPATCHABLE_OP(const MachineInstr &MI, X86MCInstLower &MCIL);
+
+  void LowerTlsAddr(X86MCInstLower &MCInstLowering, const MachineInstr &MI);
+
+  // XRay-specific lowering for X86.
+  void LowerPATCHABLE_FUNCTION_ENTER(const MachineInstr &MI,
+                                     X86MCInstLower &MCIL);
+  void LowerPATCHABLE_RET(const MachineInstr &MI, X86MCInstLower &MCIL);
+  void LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI, X86MCInstLower &MCIL);
+  void LowerPATCHABLE_EVENT_CALL(const MachineInstr &MI, X86MCInstLower &MCIL);
+
+  void LowerFENTRY_CALL(const MachineInstr &MI, X86MCInstLower &MCIL);
+
+  // Helper function that emits the XRay sleds we've collected for a particular
+  // function.
+  void EmitXRayTable();
+
+public:
+  explicit X86AsmPrinter(TargetMachine &TM,
+                         std::unique_ptr<MCStreamer> Streamer)
+      : AsmPrinter(TM, std::move(Streamer)), SM(*this), FM(*this) {}
+
+  StringRef getPassName() const override {
+    return "X86 Assembly Printer";
+  }
+
+  const X86Subtarget &getSubtarget() const { return *Subtarget; }
+
+  void EmitStartOfAsmFile(Module &M) override;
+
+  void EmitEndOfAsmFile(Module &M) override;
+
+  void EmitInstruction(const MachineInstr *MI) override;
+
+  void EmitBasicBlockEnd(const MachineBasicBlock &MBB) override {
+    SMShadowTracker.emitShadowPadding(*OutStreamer, getSubtargetInfo());
+  }
+
+  bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
+                       unsigned AsmVariant, const char *ExtraCode,
+                       raw_ostream &OS) override;
+  bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
+                             unsigned AsmVariant, const char *ExtraCode,
+                             raw_ostream &OS) override;
+
+  /// \brief Return the symbol for the specified constant pool entry.
+  MCSymbol *GetCPISymbol(unsigned CPID) const override;
+
+  bool doInitialization(Module &M) override {
+    SMShadowTracker.reset(0);
+    SM.reset();
+    return AsmPrinter::doInitialization(M);
+  }
+
+  bool runOnMachineFunction(MachineFunction &F) override;
+};
+
+} // end namespace llvm
+
+#endif