1 files changed, 26 insertions, 0 deletions
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 50c990a670..d58f7cf73d 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -845,6 +845,32 @@ static void WriteConstants(unsigned FirstVal, unsigned LastVal,
       } else {
         assert (0 && "Unknown FP type!");
       }
+    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
+      const ConstantArray *CA = cast<ConstantArray>(C);
+      // Emit constant strings specially.
+      unsigned NumOps = CA->getNumOperands();
+      // If this is a null-terminated string, use the denser CSTRING encoding.
+      if (CA->getOperand(NumOps-1)->isNullValue()) {
+        Code = bitc::CST_CODE_CSTRING;
+        --NumOps;  // Don't encode the null, which isn't allowed by char6.
+      } else {
+        Code = bitc::CST_CODE_STRING;
+        AbbrevToUse = String8Abbrev;
+      }
+      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
+      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
+      for (unsigned i = 0; i != NumOps; ++i) {
+        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
+        Record.push_back(V);
+        isCStr7 &= (V & 128) == 0;
+        if (isCStrChar6)
+          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
+      }
+
+      if (isCStrChar6)
+        AbbrevToUse = CString6Abbrev;
+      else if (isCStr7)
+        AbbrevToUse = CString7Abbrev;
     } else if (isa<ConstantDataSequential>(C) &&
                cast<ConstantDataSequential>(C)->isString()) {
       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);