1 files changed, 4 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index bfcedaceb64..3029cb10a78 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -4297,7 +4297,10 @@ bool CodeGenPrepare::extLdPromotion(TypePromotionTransaction &TPT,
     // one extension but leave one. However, we optimistically keep going,
     // because the new extension may be removed too.
     long long TotalCreatedInstsCost = CreatedInstsCost + NewCreatedInstsCost;
-    TotalCreatedInstsCost -= ExtCost;
+    // FIXME: It would be possible to propagate a negative value instead of
+    // conservatively ceiling it to 0. 
+    TotalCreatedInstsCost =
+        std::max((long long)0, (TotalCreatedInstsCost - ExtCost));
     if (!StressExtLdPromotion &&
         (TotalCreatedInstsCost > 1 ||
          !isPromotedInstructionLegal(*TLI, *DL, PromotedVal))) {