diff --git a/llvm/tools/llvm-profgen/CSPreInliner.cpp b/llvm/tools/llvm-profgen/CSPreInliner.cpp
--- a/llvm/tools/llvm-profgen/CSPreInliner.cpp
+++ b/llvm/tools/llvm-profgen/CSPreInliner.cpp
@@ -190,7 +190,11 @@
   unsigned FuncSize =
       getFuncSize(ContextTracker.getContextNodeForProfile(FSamples));
   unsigned FuncFinalSize = FuncSize;
-  unsigned SizeLimit = FuncSize * ProfileInlineGrowthLimit;
+  // Use one to avoid multiplication with a zero func size. This could happen
+  // when all of the original function's code is gone and only inlined code is
+  // left.
+  unsigned ModifiedFuncSize = FuncSize ? FuncSize : 1;
+  unsigned SizeLimit = ModifiedFuncSize * ProfileInlineGrowthLimit;
   SizeLimit = std::min(SizeLimit, (unsigned)ProfileInlineLimitMax);
   SizeLimit = std::max(SizeLimit, (unsigned)ProfileInlineLimitMin);