1 files changed, 6 insertions, 8 deletions
diff --git a/lib/DebugInfo/MSF/MSFCommon.cpp b/lib/DebugInfo/MSF/MSFCommon.cpp
index d7e1dcf31a3a..d398304375ac 100644
--- a/lib/DebugInfo/MSF/MSFCommon.cpp
+++ b/lib/DebugInfo/MSF/MSFCommon.cpp
@@ -64,15 +64,13 @@ MSFStreamLayout llvm::msf::getFpmStreamLayout(const MSFLayout &Msf,
                                               bool IncludeUnusedFpmData,
                                               bool AltFpm) {
   MSFStreamLayout FL;
-  uint32_t NumFpmIntervals = getNumFpmIntervals(Msf, IncludeUnusedFpmData);
-  support::ulittle32_t FpmBlock = Msf.SB->FreeBlockMapBlock;
-  assert(FpmBlock == 1 || FpmBlock == 2);
-  if (AltFpm) {
-    // If they requested the alternate FPM, then 2 becomes 1 and 1 becomes 2.
-    FpmBlock = 3U - FpmBlock;
-  }
+  uint32_t NumFpmIntervals =
+      getNumFpmIntervals(Msf, IncludeUnusedFpmData, AltFpm);
+
+  uint32_t FpmBlock = AltFpm ? Msf.alternateFpmBlock() : Msf.mainFpmBlock();
+
   for (uint32_t I = 0; I < NumFpmIntervals; ++I) {
-    FL.Blocks.push_back(FpmBlock);
+    FL.Blocks.push_back(support::ulittle32_t(FpmBlock));
     FpmBlock += msf::getFpmIntervalLength(Msf);
   }