Assembly and Bitcode support for unsigned/signed overflow flags and

exact sdiv flags.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76475 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 61 insertions, 4 deletions

diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index bc1eba01e2..95276b1aec 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -20,6 +20,7 @@
 #include "llvm/LLVMContext.h"
 #include "llvm/MDNode.h"
 #include "llvm/Module.h"
+#include "llvm/Operator.h"
 #include "llvm/AutoUpgrade.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
@@ -747,6 +748,18 @@ bool BitcodeReader::ResolveGlobalAndAliasInits() {
   return false;
 }
 
+static void SetOptimizationFlags(Value *V, uint64_t Flags) {
+  if (OverflowingBinaryOperator *OBO =
+        dyn_cast<OverflowingBinaryOperator>(V)) {
+    if (Flags & (1 << bitc::OBO_NO_SIGNED_OVERFLOW))
+      OBO->setHasNoSignedOverflow(true);
+    if (Flags & (1 << bitc::OBO_NO_UNSIGNED_OVERFLOW))
+      OBO->setHasNoUnsignedOverflow(true);
+  } else if (SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
+    if (Flags & (1 << bitc::SDIV_EXACT))
+      Div->setIsExact(true);
+  }
+}
 
 bool BitcodeReader::ParseConstants() {
   if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
@@ -778,7 +791,8 @@ bool BitcodeReader::ParseConstants() {
     // Read a record.
     Record.clear();
     Value *V = 0;
-    switch (Stream.ReadRecord(Code, Record)) {
+    unsigned BitCode = Stream.ReadRecord(Code, Record);
+    switch (BitCode) {
     default:  // Default behavior: unknown constant
     case bitc::CST_CODE_UNDEF:     // UNDEF
       V = Context.getUndef(CurTy);
@@ -899,6 +913,8 @@ bool BitcodeReader::ParseConstants() {
         Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
         V = Context.getConstantExpr(Opc, LHS, RHS);
       }
+      if (Record.size() >= 4)
+        SetOptimizationFlags(V, Record[3]);
       break;
     }  
     case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
@@ -1451,7 +1467,8 @@ bool BitcodeReader::ParseFunctionBody(Function *F) {
     // Read a record.
     Record.clear();
     Instruction *I = 0;
-    switch (Stream.ReadRecord(Code, Record)) {
+    unsigned BitCode = Stream.ReadRecord(Code, Record);
+    switch (BitCode) {
     default: // Default behavior: reject
       return Error("Unknown instruction");
     case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
@@ -1469,12 +1486,14 @@ bool BitcodeReader::ParseFunctionBody(Function *F) {
       Value *LHS, *RHS;
       if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
           getValue(Record, OpNum, LHS->getType(), RHS) ||
-          OpNum+1 != Record.size())
+          OpNum+1 > Record.size())
         return Error("Invalid BINOP record");
       
-      int Opc = GetDecodedBinaryOpcode(Record[OpNum], LHS->getType());
+      int Opc = GetDecodedBinaryOpcode(Record[OpNum++], LHS->getType());
       if (Opc == -1) return Error("Invalid BINOP record");
       I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
+      if (OpNum < Record.size())
+        SetOptimizationFlags(I, Record[3]);
       break;
     }
     case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index d7acd14a80..d245e5bcb1 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -21,6 +21,7 @@
 #include "llvm/Instructions.h"
 #include "llvm/MDNode.h"
 #include "llvm/Module.h"
+#include "llvm/Operator.h"
 #include "llvm/TypeSymbolTable.h"
 #include "llvm/ValueSymbolTable.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -50,6 +51,7 @@ enum {
   // FUNCTION_BLOCK abbrev id's.
   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
   FUNCTION_INST_BINOP_ABBREV,
+  FUNCTION_INST_BINOP_FLAGS_ABBREV,
   FUNCTION_INST_CAST_ABBREV,
   FUNCTION_INST_RET_VOID_ABBREV,
   FUNCTION_INST_RET_VAL_ABBREV,
@@ -454,6 +456,22 @@ static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
   }
 }
 
+static uint64_t GetOptimizationFlags(const Value *V) {
+  uint64_t Flags = 0;
+
+  if (const OverflowingBinaryOperator *OBO =
+        dyn_cast<OverflowingBinaryOperator>(V)) {
+    if (OBO->hasNoSignedOverflow())
+      Flags |= 1 << bitc::OBO_NO_SIGNED_OVERFLOW;
+    if (OBO->hasNoUnsignedOverflow())
+      Flags |= 1 << bitc::OBO_NO_UNSIGNED_OVERFLOW;
+  } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
+    if (Div->isExact())
+      Flags |= 1 << bitc::SDIV_EXACT;
+  }
+
+  return Flags;
+}
 
 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
                            const ValueEnumerator &VE,
@@ -641,6 +659,9 @@ static void WriteConstants(unsigned FirstVal, unsigned LastVal,
           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
           Record.push_back(VE.getValueID(C->getOperand(0)));
           Record.push_back(VE.getValueID(C->getOperand(1)));
+          uint64_t Flags = GetOptimizationFlags(CE);
+          if (Flags != 0)
+            Record.push_back(Flags);
         }
         break;
       case Instruction::GetElementPtr:
@@ -778,6 +799,12 @@ static void WriteInstruction(const Instruction &I, unsigned InstID,
         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
       Vals.push_back(VE.getValueID(I.getOperand(1)));
       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
+      uint64_t Flags = GetOptimizationFlags(&I);
+      if (Flags != 0) {
+        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
+          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
+        Vals.push_back(Flags);
+      }
     }
     break;
 
@@ -1225,6 +1252,17 @@ static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
       llvm_unreachable("Unexpected abbrev ordering!");
   }
+  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
+    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
+                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
   { // INST_CAST abbrev for FUNCTION_BLOCK.
     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));