Recommited r156374 with critical fixes in BitcodeReader/Writer:

Ordinary patch for PR1255.
Added new case-ranges orientated methods for adding/removing cases in SwitchInst. After this patch cases will internally representated as ConstantArray-s instead of ConstantInt, externally cases wrapped within the ConstantRangesSet object.
Old methods of SwitchInst are also works well, but marked as deprecated. So on this stage we have no side effects except that I added support for case ranges in BitcodeReader/Writer, of course test for Bitcode is also added. Old "switch" format is also supported.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156704 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 149 insertions, 37 deletions

diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 040f3438fe..49b6e4f42a 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -28,6 +28,10 @@
 #include "llvm/OperandTraits.h"
 using namespace llvm;
 
+enum {
+  SWITCH_INST_MAGIC = 0x4B5 // May 2012 => 1205 => Hex
+};
+
 void BitcodeReader::materializeForwardReferencedFunctions() {
   while (!BlockAddrFwdRefs.empty()) {
     Function *F = BlockAddrFwdRefs.begin()->first;
@@ -927,6 +931,16 @@ bool BitcodeReader::ResolveGlobalAndAliasInits() {
   return false;
 }
 
+APInt ReadWideAPInt(const uint64_t *Vals, unsigned ActiveWords,
+                    unsigned TypeBits) {
+  SmallVector<uint64_t, 8> Words;
+  Words.resize(ActiveWords);
+  for (unsigned i = 0; i != ActiveWords; ++i)
+    Words[i] = DecodeSignRotatedValue(Vals[i]);
+  
+  return APInt(TypeBits, Words);
+}
+
 bool BitcodeReader::ParseConstants() {
   if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
     return Error("Malformed block record");
@@ -983,13 +997,11 @@ bool BitcodeReader::ParseConstants() {
         return Error("Invalid WIDE_INTEGER record");
 
       unsigned NumWords = Record.size();
-      SmallVector<uint64_t, 8> Words;
-      Words.resize(NumWords);
-      for (unsigned i = 0; i != NumWords; ++i)
-        Words[i] = DecodeSignRotatedValue(Record[i]);
-      V = ConstantInt::get(Context,
-                           APInt(cast<IntegerType>(CurTy)->getBitWidth(),
-                                 Words));
+      
+      APInt VInt = ReadWideAPInt(&Record[0], NumWords,
+          cast<IntegerType>(CurTy)->getBitWidth());
+      V = ConstantInt::get(Context, VInt);
+      
       break;
     }
     case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
@@ -2221,6 +2233,62 @@ bool BitcodeReader::ParseFunctionBody(Function *F) {
       break;
     }
     case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, op0, op1, ...]
+      // Check magic 
+      if ((Record[0] >> 16) == SWITCH_INST_MAGIC) {
+        // New SwitchInst format with case ranges.
+        
+        Type *OpTy = getTypeByID(Record[1]);
+        unsigned ValueBitWidth = cast<IntegerType>(OpTy)->getBitWidth();
+
+        Value *Cond = getFnValueByID(Record[2], OpTy);
+        BasicBlock *Default = getBasicBlock(Record[3]);
+        if (OpTy == 0 || Cond == 0 || Default == 0)
+          return Error("Invalid SWITCH record");
+
+        unsigned NumCases = Record[4];
+        
+        SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
+        InstructionList.push_back(SI);
+        
+        unsigned CurIdx = 5;
+        for (unsigned i = 0; i != NumCases; ++i) {
+          CRSBuilder CaseBuilder;
+          unsigned NumItems = Record[CurIdx++];
+          for (unsigned ci = 0; ci != NumItems; ++ci) {
+            bool isSingleNumber = Record[CurIdx++];
+            
+            APInt Low;
+            unsigned ActiveWords = 1;
+            if (ValueBitWidth > 64)
+              ActiveWords = Record[CurIdx++];
+            Low = ReadWideAPInt(&Record[CurIdx], ActiveWords, ValueBitWidth);
+            CurIdx += ActiveWords;
+            
+            if (!isSingleNumber) {
+              ActiveWords = 1;
+              if (ValueBitWidth > 64)
+                ActiveWords = Record[CurIdx++];
+              APInt High =
+                  ReadWideAPInt(&Record[CurIdx], ActiveWords, ValueBitWidth);
+              CaseBuilder.add(cast<ConstantInt>(ConstantInt::get(OpTy, Low)),
+                              cast<ConstantInt>(ConstantInt::get(OpTy, High)));
+              CurIdx += ActiveWords;
+            } else
+              CaseBuilder.add(cast<ConstantInt>(ConstantInt::get(OpTy, Low)));
+          }
+          BasicBlock *DestBB = getBasicBlock(Record[CurIdx++]);
+          ConstantRangesSet Case = CaseBuilder.getCase(); 
+          SI->addCase(Case, DestBB);
+        }
+        uint16_t Hash = SI->Hash();
+        if (Hash != (Record[0] & 0xFFFF))
+          return Error("Invalid SWITCH record");
+        I = SI;
+        break;
+      }
+      
+      // Old SwitchInst format without case ranges.
+      
       if (Record.size() < 3 || (Record.size() & 1) == 0)
         return Error("Invalid SWITCH record");
       Type *OpTy = getTypeByID(Record[0]);
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index b25d2e96d5..ae250ebe16 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -62,7 +62,10 @@ enum {
   FUNCTION_INST_CAST_ABBREV,
   FUNCTION_INST_RET_VOID_ABBREV,
   FUNCTION_INST_RET_VAL_ABBREV,
-  FUNCTION_INST_UNREACHABLE_ABBREV
+  FUNCTION_INST_UNREACHABLE_ABBREV,
+  
+  // SwitchInst Magic
+  SWITCH_INST_MAGIC = 0x4B5 // May 2012 => 1205 => Hex
 };
 
 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
@@ -719,6 +722,41 @@ static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
   Stream.ExitBlock();
 }
 
+static void EmitAPInt(SmallVectorImpl<uint64_t> &Vals,
+                      unsigned &Code, unsigned &AbbrevToUse, const APInt &Val,
+                      bool EmitSizeForWideNumbers = false
+                      ) {
+  if (Val.getBitWidth() <= 64) {
+    uint64_t V = Val.getSExtValue();
+    if ((int64_t)V >= 0)
+      Vals.push_back(V << 1);
+    else
+      Vals.push_back((-V << 1) | 1);
+    Code = bitc::CST_CODE_INTEGER;
+    AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
+  } else {
+    // Wide integers, > 64 bits in size.
+    // We have an arbitrary precision integer value to write whose
+    // bit width is > 64. However, in canonical unsigned integer
+    // format it is likely that the high bits are going to be zero.
+    // So, we only write the number of active words.
+    unsigned NWords = Val.getActiveWords();
+    
+    if (EmitSizeForWideNumbers)
+      Vals.push_back(NWords);
+    
+    const uint64_t *RawWords = Val.getRawData();
+    for (unsigned i = 0; i != NWords; ++i) {
+      int64_t V = RawWords[i];
+      if (V >= 0)
+        Vals.push_back(V << 1);
+      else
+        Vals.push_back((-V << 1) | 1);
+    }
+    Code = bitc::CST_CODE_WIDE_INTEGER;
+  }
+}
+
 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
                            const ValueEnumerator &VE,
                            BitstreamWriter &Stream, bool isGlobal) {
@@ -801,30 +839,7 @@ static void WriteConstants(unsigned FirstVal, unsigned LastVal,
     } else if (isa<UndefValue>(C)) {
       Code = bitc::CST_CODE_UNDEF;
     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
-      if (IV->getBitWidth() <= 64) {
-        uint64_t V = IV->getSExtValue();
-        if ((int64_t)V >= 0)
-          Record.push_back(V << 1);
-        else
-          Record.push_back((-V << 1) | 1);
-        Code = bitc::CST_CODE_INTEGER;
-        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
-      } else {                             // Wide integers, > 64 bits in size.
-        // We have an arbitrary precision integer value to write whose
-        // bit width is > 64. However, in canonical unsigned integer
-        // format it is likely that the high bits are going to be zero.
-        // So, we only write the number of active words.
-        unsigned NWords = IV->getValue().getActiveWords();
-        const uint64_t *RawWords = IV->getValue().getRawData();
-        for (unsigned i = 0; i != NWords; ++i) {
-          int64_t V = RawWords[i];
-          if (V >= 0)
-            Record.push_back(V << 1);
-          else
-            Record.push_back((-V << 1) | 1);
-        }
-        Code = bitc::CST_CODE_WIDE_INTEGER;
-      }
+      EmitAPInt(Record, Code, AbbrevToUse, IV->getValue());
     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
       Code = bitc::CST_CODE_FLOAT;
       Type *Ty = CFP->getType();
@@ -1137,16 +1152,45 @@ static void WriteInstruction(const Instruction &I, unsigned InstID,
     break;
   case Instruction::Switch:
     {
+      // Redefine Vals, since here we need to use 64 bit values
+      // explicitly to store large APInt numbers.
+      SmallVector<uint64_t, 128> Vals64;
+      
       Code = bitc::FUNC_CODE_INST_SWITCH;
       SwitchInst &SI = cast<SwitchInst>(I);
-      Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
-      Vals.push_back(VE.getValueID(SI.getCondition()));
-      Vals.push_back(VE.getValueID(SI.getDefaultDest()));
+      
+      uint32_t SwitchRecordHeader = SI.Hash() | (SWITCH_INST_MAGIC << 16); 
+      Vals64.push_back(SwitchRecordHeader);      
+      
+      Vals64.push_back(VE.getTypeID(SI.getCondition()->getType()));
+      Vals64.push_back(VE.getValueID(SI.getCondition()));
+      Vals64.push_back(VE.getValueID(SI.getDefaultDest()));
+      Vals64.push_back(SI.getNumCases());
       for (SwitchInst::CaseIt i = SI.case_begin(), e = SI.case_end();
            i != e; ++i) {
-        Vals.push_back(VE.getValueID(i.getCaseValue()));
-        Vals.push_back(VE.getValueID(i.getCaseSuccessor()));
+        ConstantRangesSet CRS = i.getCaseValueEx();
+        Vals64.push_back(CRS.getNumItems());
+        for (unsigned ri = 0, rn = CRS.getNumItems(); ri != rn; ++ri) {
+          ConstantRangesSet::Range r = CRS.getItem(ri);
+
+          Vals64.push_back(CRS.isSingleNumber(ri));
+
+          const APInt &Low = r.Low->getValue();
+          const APInt &High = r.High->getValue();
+          unsigned Code, Abbrev; // will unused.
+          
+          EmitAPInt(Vals64, Code, Abbrev, Low, true);
+          if (r.Low != r.High)
+            EmitAPInt(Vals64, Code, Abbrev, High, true);
+        }
+        Vals64.push_back(VE.getValueID(i.getCaseSuccessor()));
       }
+      
+      Stream.EmitRecord(Code, Vals64, AbbrevToUse);
+      
+      // Also do expected action - clear external Vals collection:
+      Vals.clear();
+      return;
     }
     break;
   case Instruction::IndirectBr: