diff --git a/llvm/test/tools/llvm-exegesis/X86/latency-IN16rr.s b/llvm/test/tools/llvm-exegesis/X86/latency-IN16rr.s
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/llvm-exegesis/X86/latency-IN16rr.s
@@ -0,0 +1,12 @@
+# RUN: llvm-exegesis -mode=latency -opcode-name=IN16rr -repetition-mode=duplicate | FileCheck %s
+
+CHECK:      ---
+CHECK-NEXT: mode: latency
+CHECK-NEXT: key:
+CHECK-NEXT:   instructions:
+CHECK-NEXT:     - 'IN16rr'
+CHECK-NEXT:     - {{.*}}
+CHECK-NEXT: config: ''
+CHECK-NEXT: register_initial_values:
+CHECK-DAG: - '[[REG1:[A-Z0-9]+]]=0x0'
+CHECK-LAST: ...
diff --git a/llvm/tools/llvm-exegesis/lib/SerialSnippetGenerator.cpp b/llvm/tools/llvm-exegesis/lib/SerialSnippetGenerator.cpp
--- a/llvm/tools/llvm-exegesis/lib/SerialSnippetGenerator.cpp
+++ b/llvm/tools/llvm-exegesis/lib/SerialSnippetGenerator.cpp
@@ -140,7 +140,7 @@
       InstructionTemplate OtherIT(OtherInstr);
       if (!Forward.hasImplicitAliasing())
         setRandomAliasing(Forward, ThisIT, OtherIT);
-      if (!Back.hasImplicitAliasing())
+      else if (!Back.hasImplicitAliasing())
         setRandomAliasing(Back, OtherIT, ThisIT);
       CodeTemplate CT;
       CT.Execution = ExecutionModeBit;