[PATCH] D54244: [HotColdSplitting] Refine definition of unlikelyExecuted

[Vedant Kumar via Phabricator via llvm-commits]

vsk added inline comments.


================
Comment at: llvm/lib/Transforms/IPO/HotColdSplitting.cpp:106-120
+  if (blockEndsInUnreachable(BB)) {
+    // Calls to noreturn functions are followed by an unreachable inst, but
+    // the call itself may be warm (e.g. longjmp, or exit).
+    if (auto *CI =
+            dyn_cast_or_null<CallInst>(BB.getTerminator()->getPrevNode()))
+      if (CI->hasFnAttr(Attribute::NoReturn) && !CI->hasFnAttr(Attribute::Cold))
+        return false;
----------------
junbuml wrote:
> 
> 
> It seems that the case below will be ended up with warm.  Don't we need to see this case as cold? 
> 
> ```
> BB:
>   ..... 
>   call void @sink()
>   ...... 
>   tail call void @longjmp(%struct.__jmp_buf_tag* %1, i32 0)
>   unreachable
> 
> declare void @sink() cold
> declare void @longjmp(%struct.__jmp_buf_tag*, i32) noreturn nounwind
> ```
Thanks for pointing this out.


https://reviews.llvm.org/D54244