[llvm] [InstCombine] Fold values to 0 on eq-dominated paths (PR #174083)

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github-actions[bot] wrote:

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


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

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<summary>
View the diff from clang-format here.
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``````````diff
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index b539c4848..a8c6c57ce 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -2295,24 +2295,29 @@ Instruction *InstCombinerImpl::visitSub(BinaryOperator &I) {
   for (User *U : I.users()) {
     auto *UseI = dyn_cast<Instruction>(U);
 
-    if (!UseI) continue;
+    if (!UseI)
+      continue;
 
     BasicBlock *BB = UseI->getParent();
     BasicBlock *Pred = BB->getSinglePredecessor();
 
-    if (!Pred) continue;
+    if (!Pred)
+      continue;
 
     auto *Br = dyn_cast<BranchInst>(Pred->getTerminator());
 
-    if (!Br || !Br->isConditional()) continue;
+    if (!Br || !Br->isConditional())
+      continue;
 
     auto *Cmp = dyn_cast<ICmpInst>(Br->getCondition());
 
-    if (!Cmp || Cmp->getPredicate() != ICmpInst::ICMP_EQ) continue;
+    if (!Cmp || Cmp->getPredicate() != ICmpInst::ICMP_EQ)
+      continue;
     if (!((Cmp->getOperand(0) == Op0 && Cmp->getOperand(1) == Op1) ||
-        (Cmp->getOperand(0) == Op1 && Cmp->getOperand(1) == Op0)))
+          (Cmp->getOperand(0) == Op1 && Cmp->getOperand(1) == Op0)))
+      continue;
+    if (Br->getSuccessor(0) != BB)
       continue;
-    if (Br->getSuccessor(0) != BB) continue;
 
     UseI->replaceUsesOfWith(&I, ConstantInt::get(I.getType(), 0));
   }

``````````

</details>


https://github.com/llvm/llvm-project/pull/174083