diff --git a/llvm/utils/lit/lit/TestRunner.py b/llvm/utils/lit/lit/TestRunner.py
--- a/llvm/utils/lit/lit/TestRunner.py
+++ b/llvm/utils/lit/lit/TestRunner.py
@@ -971,7 +971,7 @@
                 out += "# redirected output from %r:\n" % (name,)
                 data = to_string(data.decode('utf-8', errors='replace'))
                 if len(data) > 1024:
-                    out += data[:1024] + "\n...\n"
+                    out += data[:512] + "\n...\n" + data[-512:]
                     out += "note: data was truncated\n"
                 else:
                     out += data