2 files changed, 20 insertions, 14 deletions
diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index 0bdc3506a30..88f359d4fd5 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -903,20 +903,7 @@ lltok::Kind LLLexer::LexDigitOrNegative() {
   if (CurPtr[0] != '.') {
     if (TokStart[0] == '0' && TokStart[1] == 'x')
       return Lex0x();
-    unsigned Len = CurPtr-TokStart;
-    uint32_t numBits = ((Len * 64) / 19) + 2;
-    APInt Tmp(numBits, StringRef(TokStart, Len), 10);
-    if (TokStart[0] == '-') {
-      uint32_t minBits = Tmp.getMinSignedBits();
-      if (minBits > 0 && minBits < numBits)
-        Tmp = Tmp.trunc(minBits);
-      APSIntVal = APSInt(Tmp, false);
-    } else {
-      uint32_t activeBits = Tmp.getActiveBits();
-      if (activeBits > 0 && activeBits < numBits)
-        Tmp = Tmp.trunc(activeBits);
-      APSIntVal = APSInt(Tmp, true);
-    }
+    APSIntVal = APSInt(StringRef(TokStart, CurPtr - TokStart));
     return lltok::APSInt;
   }
 
diff --git a/llvm/lib/Support/APSInt.cpp b/llvm/lib/Support/APSInt.cpp
index 73acafa690c..975457c070a 100644
--- a/llvm/lib/Support/APSInt.cpp
+++ b/llvm/lib/Support/APSInt.cpp
@@ -17,6 +17,25 @@
 
 using namespace llvm;
 
+APSInt::APSInt(StringRef Str) {
+  assert(!Str.empty() && "Invalid string length");
+
+  // (Over-)estimate the required number of bits.
+  unsigned NumBits = ((Str.size() * 64) / 19) + 2;
+  APInt Tmp(NumBits, Str, /*Radix=*/10);
+  if (Str[0] == '-') {
+    unsigned MinBits = Tmp.getMinSignedBits();
+    if (MinBits > 0 && MinBits < NumBits)
+      Tmp = Tmp.trunc(MinBits);
+    *this = APSInt(Tmp, /*IsUnsigned=*/false);
+    return;
+  }
+  unsigned ActiveBits = Tmp.getActiveBits();
+  if (ActiveBits > 0 && ActiveBits < NumBits)
+    Tmp = Tmp.trunc(ActiveBits);
+  *this = APSInt(Tmp, /*IsUnsigned=*/true);
+}
+
 void APSInt::Profile(FoldingSetNodeID& ID) const {
   ID.AddInteger((unsigned) (IsUnsigned ? 1 : 0));
   APInt::Profile(ID);