diff --git a/llvm/lib/BinaryFormat/XCOFF.cpp b/llvm/lib/BinaryFormat/XCOFF.cpp
--- a/llvm/lib/BinaryFormat/XCOFF.cpp
+++ b/llvm/lib/BinaryFormat/XCOFF.cpp
@@ -117,7 +117,7 @@
   unsigned ParsedNum = 0;
   unsigned ParmsNum = FixedParmsNum + FloatingParmsNum;
 
-  while (Bits < 32 && ParsedNum < ParmsNum) {
+  while (Bits < 31 && ParsedNum < ParmsNum) {
     if (++ParsedNum > 1)
       ParmsType += ", ";
     if ((Value & TracebackTable::ParmTypeIsFloatingBit) == 0) {