[llvm] [InstCombine] Keep branch weights when folding a shift through a select (PR #227987)

[Alok Kumar Sharma via llvm-commits]

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@@ -994,7 +994,10 @@ Instruction *InstCombinerImpl::FoldShiftByConstant(Value *Op0, Constant *C1,
 
       Value *NewShift = Builder.CreateBinOp(I.getOpcode(), FalseVal, C1);
       Value *NewOp = Builder.CreateBinOp(TBO->getOpcode(), NewShift, NewRHS);
-      return SelectInst::Create(Cond, NewOp, NewShift);
+      auto *NewSel = SelectInst::Create(Cond, NewOp, NewShift);
+      if (auto *SI = dyn_cast<SelectInst>(Op0))
+        NewSel->copyMetadata(*SI, {LLVMContext::MD_prof});
+      return NewSel;
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alokkrsharma wrote:

Done, thanks. I've switched to MDFrom now.

https://github.com/llvm/llvm-project/pull/227987