avoid undef behavior on minint, fixing PR7783.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110114 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Support/raw_ostream.cpp b/lib/Support/raw_ostream.cpp
index 8054ae63688c926b22e74c7d323ba637c3d5a1a3..ac118a91a3f6b19660d9002693dca3919a979d7c 100644 (file)
--- a/lib/Support/raw_ostream.cpp
+++ b/lib/Support/raw_ostream.cpp
@@ -143,9 +143,10 @@ raw_ostream &raw_ostream::operator<<(unsigned long long N) {
 }
 
 raw_ostream &raw_ostream::operator<<(long long N) {
-  if (N <  0) {
+  if (N < 0) {
     *this << '-';
-    N = -N;
+    // Avoid undefined behavior on INT64_MIN with a cast.
+    N = -(unsigned long long)N;
   }
 
   return this->operator<<(static_cast<unsigned long long>(N));