[llvm] [InstCombine] Fold lshr/ashr (mul X, 2^N + 2^M) -> add (X, lshr/ashr X, N - M) (PR #210140)

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<!--LLVM CODE FORMAT COMMENT: {clang-format}-->


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``````````bash
git-clang-format --diff origin/main HEAD --extensions cpp -- llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp --diff_from_common_commit
``````````

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View the diff from clang-format here.
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``````````diff
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
index cfe884636..b56d9c77f 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
@@ -1912,8 +1912,8 @@ Instruction *InstCombinerImpl::visitAShr(BinaryOperator &I) {
       if (M_API.isPowerOf2()) {
         unsigned M = M_API.logBase2();
         // ashr (mul nsw (X, 2^N + 2^M)), N -> add nsw (X, ashr(X, N - M))
-        Value *ShiftedX = Builder.CreateAShr(
-            X, ConstantInt::get(Ty, ShAmt - M), "", I.isExact());
+        Value *ShiftedX = Builder.CreateAShr(X, ConstantInt::get(Ty, ShAmt - M),
+                                             "", I.isExact());
         auto *NewAdd = BinaryOperator::CreateNSWAdd(X, ShiftedX);
         NewAdd->setHasNoUnsignedWrap(
             cast<OverflowingBinaryOperator>(Op0)->hasNoUnsignedWrap());

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https://github.com/llvm/llvm-project/pull/210140