Extend Range analysis to 64-bit range and mint operations

runtime/platform/utils.h

Index: runtime/platform/utils.h
diff --git a/runtime/platform/utils.h b/runtime/platform/utils.h
index f2025624ca6e76eb5c792ea2e1e0971ce0a4c685..ebecfeb9b5b73d1dfccdc2715d3344b86f3b5261 100644
--- a/runtime/platform/utils.h
+++ b/runtime/platform/utils.h
@@ -171,6 +171,19 @@ class Utils {
            count <= (length - offset);
   }
 
+  static inline bool DidAddOverflow(int64_t a, int64_t b, int64_t result) {
+    // a & b have same sign but result has a different sign.
+    return ((a < 0) && (b < 0) && (result > 0)) ||
+           ((a > 0) && (b > 0) && (result < 0));
+  }
+
+  static inline bool DidSubOverflow(int64_t a, int64_t b, int64_t result) {
+    // a & b have different signs and result has a different sign than a.
+    return ((a < 0) && (b > 0) && (result > 0)) ||
+           ((a > 0) && (b < 0) && (result < 0));
+  }
+
+
   // Utility functions for converting values from host endianess to
   // big or little endian values.
   static uint16_t HostToBigEndian16(uint16_t host_value);