MC: Tweak MCInstFragment to include the encoded data and fixups, so that we don't need to recompute them during relaxation. I will revisit this once all the other pieces of fast relaxation are in place.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99244 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 42 insertions, 21 deletions

diff --git a/include/llvm/MC/MCAssembler.h b/include/llvm/MC/MCAssembler.h
index ff32eb26fc..d7f1acea35 100644
--- a/include/llvm/MC/MCAssembler.h
+++ b/include/llvm/MC/MCAssembler.h
@@ -180,28 +180,57 @@ public:
   virtual void dump();
 };
 
+// FIXME: This current incarnation of MCInstFragment doesn't make much sense, as
+// it is almost entirely a duplicate of MCDataFragment. If we decide to stick
+// with this approach (as opposed to making MCInstFragment a very light weight
+// object with just the MCInst and a code size, then we should just change
+// MCDataFragment to have an optional MCInst at its end.
 class MCInstFragment : public MCFragment {
   /// Inst - The instruction this is a fragment for.
   MCInst Inst;
 
   /// InstSize - The size of the currently encoded instruction.
-  unsigned InstSize;
+  SmallString<8> Code;
+
+  /// Fixups - The list of fixups in this fragment.
+  SmallVector<MCAsmFixup, 1> Fixups;
 
 public:
-  MCInstFragment(MCInst _Inst, unsigned _InstSize, MCSectionData *SD = 0)
-    : MCFragment(FT_Inst, SD), Inst(_Inst), InstSize(_InstSize) {}
+  typedef SmallVectorImpl<MCAsmFixup>::const_iterator const_fixup_iterator;
+  typedef SmallVectorImpl<MCAsmFixup>::iterator fixup_iterator;
+
+public:
+  MCInstFragment(MCInst _Inst, MCSectionData *SD = 0)
+    : MCFragment(FT_Inst, SD), Inst(_Inst) {
+  }
 
   /// @name Accessors
   /// @{
 
-  unsigned getInstSize() const { return InstSize; }
+  SmallVectorImpl<char> &getCode() { return Code; }
+  const SmallVectorImpl<char> &getCode() const { return Code; }
 
+  unsigned getInstSize() const { return Code.size(); }
+
+  MCInst &getInst() { return Inst; }
   const MCInst &getInst() const { return Inst; }
 
-  void setInst(MCInst Inst, unsigned InstSize) {
-    this->Inst = Inst;
-    this->InstSize = InstSize;
-  }
+  void setInst(MCInst Value) { Inst = Value; }
+
+  /// @}
+  /// @name Fixup Access
+  /// @{
+
+  SmallVectorImpl<MCAsmFixup> &getFixups() { return Fixups; }
+  const SmallVectorImpl<MCAsmFixup> &getFixups() const { return Fixups; }
+
+  fixup_iterator fixup_begin() { return Fixups.begin(); }
+  const_fixup_iterator fixup_begin() const { return Fixups.begin(); }
+
+  fixup_iterator fixup_end() {return Fixups.end();}
+  const_fixup_iterator fixup_end() const {return Fixups.end();}
+
+  size_t fixup_size() const { return Fixups.size(); }
 
   /// @}
 
diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index ba2e5de73e..39bad6dea4 100644
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -773,22 +773,14 @@ void MCAssembler::FinishLayout(MCAsmLayout &Layout) {
       SD.getFragmentList().insert(it2, DF);
 
       // Update the data fragments layout data.
+      DF->setParent(IF->getParent());
       DF->setOffset(IF->getOffset());
       DF->setFileSize(IF->getInstSize());
 
-      // Encode the final instruction.
-      SmallVector<MCFixup, 4> Fixups;
-      raw_svector_ostream VecOS(DF->getContents());
-      getEmitter().EncodeInstruction(IF->getInst(), VecOS, Fixups);
-
-      // Copy over the fixups.
-      //
-      // FIXME-PERF: Encode fixups directly into the data fragment as well.
-      for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
-        MCFixup &F = Fixups[i];
-        DF->addFixup(MCAsmFixup(DF->getContents().size()+F.getOffset(),
-                                *F.getValue(), F.getKind()));
-      }
+      // Copy in the data and the fixups.
+      DF->getContents().append(IF->getCode().begin(), IF->getCode().end());
+      for (unsigned i = 0, e = IF->getFixups().size(); i != e; ++i)
+        DF->getFixups().push_back(IF->getFixups()[i]);
 
       // Delete the instruction fragment and update the iterator.
       SD.getFragmentList().erase(IF);