Index: llvm/lib/Transforms/IPO/HotColdSplitting.cpp
===================================================================
--- llvm/lib/Transforms/IPO/HotColdSplitting.cpp
+++ llvm/lib/Transforms/IPO/HotColdSplitting.cpp
@@ -358,6 +358,13 @@
       CS.setCallingConv(CallingConv::Cold);
     }
     CI->setIsNoInline();
+
+    // Try to make the outlined code as small as possible on the assumption
+    // that it's cold.
+    assert(!OutF->hasFnAttribute(Attribute::OptimizeNone) &&
+           "An outlined function should never be marked optnone");
+    OutF->addFnAttr(Attribute::MinSize);
+
     LLVM_DEBUG(llvm::dbgs() << "Outlined Region: " << *OutF);
     return OutF;
   }
Index: llvm/test/Transforms/HotColdSplit/minsize.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/HotColdSplit/minsize.ll
@@ -0,0 +1,32 @@
+; RUN: opt -hotcoldsplit -S < %s | FileCheck %s
+
+; CHECK-LABEL: @fun
+; CHECK: codeRepl:
+; CHECK-NEXT: call void @fun_if.else
+
+define void @fun() {
+entry:
+  br i1 undef, label %if.then, label %if.else
+
+if.then:
+  ret void
+
+if.else:
+  br label %if.then4
+
+if.then4:
+  br i1 undef, label %if.then5, label %if.end
+
+if.then5:
+  br label %cleanup
+
+if.end:
+  br label %cleanup
+
+cleanup:
+  %cleanup.dest.slot.0 = phi i32 [ 1, %if.then5 ], [ 0, %if.end ]
+  unreachable
+}
+
+; CHECK: define {{.*}} @fun_if.else{{.*}}#[[outlined_func_attr:[0-9]+]]
+; CHECK: attributes #[[outlined_func_attr]] = { {{.*}}minsize