Add hybrid assembler concept to ARM assembler.

src/IceAssembler.h

 //===- subzero/src/IceAssembler.h - Integrated assembler --------*- C++ -*-===//
 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // Modified by the Subzero authors.
 //
 //===----------------------------------------------------------------------===//
 //
 //                        The Subzero Code Generator
@@ skipping 156 matching lines @@
     // Disable the actual check in non-debug mode.
     return true;
   }
 
   /// Returns the position in the instruction stream.
   intptr_t getPosition() const { return Cursor - Contents; }
 
   /// Create and track a fixup in the current function.
   AssemblerFixup *createFixup(FixupKind Kind, const Constant *Value);
 
+  /// Create and track a textual fixup in the current function.
+  AssemblerTextFixup *createTextFixup(const std::string &Text,
+                                      size_t BytesUsed);
+
+  /// Mark that an attempt was made to emit, but failed. Hence, in order to
+  /// continue, one must emit a text fixup.
+  void setNeedsTextFixup() { TextFixupNeeded = true; }
+
+  /// Returns true if last emit failed and needs a text fixup.
+  bool needsTextFixup() const { return TextFixupNeeded; }
+
+  /// Installs a created fixup, after it has been allocated.
+  void installFixup(AssemblerFixup *F);
+
   const FixupRefList &fixups() const { return Fixups; }
 
   void setSize(intptr_t NewSize) {
     assert(NewSize <= size());
     Cursor = Contents + NewSize;
   }
 
 private:
   /// The limit is set to kMinimumGap bytes before the end of the data area.
   /// This leaves enough space for the longest possible instruction and allows
   /// for a single, fast space check per instruction.
   static constexpr intptr_t kMinimumGap = 32;
 
   uintptr_t Contents;
   uintptr_t Cursor;
   uintptr_t Limit;
   // The member variable is named Assemblr to avoid hiding the class Assembler.
   Assembler &Assemblr;
   /// List of pool-allocated fixups relative to the current function.
   FixupRefList Fixups;
+  // True if a textual fixup is needed, because the assembler was unable to
+  // emit the last request.
+  bool TextFixupNeeded;
 
   uintptr_t cursor() const { return Cursor; }
   uintptr_t limit() const { return Limit; }
   intptr_t capacity() const {
     assert(Limit >= Contents);
     return (Limit - Contents) + kMinimumGap;
   }
 
   /// Compute the limit based on the data area and the capacity. See description
   /// of kMinimumGap for the reasoning behind the value.
@@ skipping 54 matching lines @@
   virtual Label *getCfgNodeLabel(SizeT NodeNumber) = 0;
   /// Mark the current text location as the start of a CFG node (represented by
   /// NodeNumber).
   virtual void bindCfgNodeLabel(SizeT NodeNumber) = 0;
 
   virtual bool fixupIsPCRel(FixupKind Kind) const = 0;
 
   // Return a view of all the bytes of code for the current function.
   llvm::StringRef getBufferView() const;
 
+  /// Emit a fixup at the current location.
+  void emitFixup(AssemblerFixup *Fixup) { Buffer.emitFixup(Fixup); }
+
   const FixupRefList &fixups() const { return Buffer.fixups(); }
 
   AssemblerFixup *createFixup(FixupKind Kind, const Constant *Value) {
     return Buffer.createFixup(Kind, Value);
   }
 
+  AssemblerTextFixup *createTextFixup(const std::string &Text,
+                                      size_t BytesUsed) {
+    return Buffer.createTextFixup(Text, BytesUsed);
+  }
+
+  void setNeedsTextFixup() { Buffer.setNeedsTextFixup(); }
+
+  bool needsTextFixup() const { return Buffer.needsTextFixup(); }
+
   void emitIASBytes() const;
   bool getInternal() const { return IsInternal; }
   void setInternal(bool Internal) { IsInternal = Internal; }
   const IceString &getFunctionName() { return FunctionName; }
   void setFunctionName(const IceString &NewName) { FunctionName = NewName; }
   intptr_t getBufferSize() const { return Buffer.size(); }
   /// Roll back to a (smaller) size.
   void setBufferSize(intptr_t NewSize) { Buffer.setSize(NewSize); }
   void setPreliminary(bool Value) { Preliminary = Value; }
   bool getPreliminary() const { return Preliminary; }
@@ skipping 12 matching lines @@
   /// since the Cfg object may be deleted by the time the assembler buffer is
   /// emitted.
   IceString FunctionName = "";
   bool IsInternal = false;
   /// Preliminary indicates whether a preliminary pass is being made for
   /// calculating bundle padding (Preliminary=true), versus the final pass where
   /// all changes to label bindings, label links, and relocation fixups are
   /// fully committed (Preliminary=false).
   bool Preliminary = false;
 
+  /// Installs a created fixup, after it has been allocated.
+  void installFixup(AssemblerFixup *F) { Buffer.installFixup(F); }
+
 protected:
   GlobalContext *Ctx;
   // Buffer's constructor uses the Allocator, so it needs to appear after it.
   // TODO(jpp): dependencies on construction order are a nice way of shooting
   // yourself in the foot. Fix this.
   AssemblerBuffer Buffer;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEASSEMBLER_H_