[llvm] [BPI] Use BasicBlock::isEHPad() to check exception handling block. (PR #95771)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-analysis

Author: Enna1 (Enna1)

<details>
<summary>Changes</summary>

There is no need to iterate all predecessors of current block, check if current block is the invoke unwind destination of any predecessor. We can directly call `BasicBlock::isEHPad()` to check if current block is an exception handling block.

---
Full diff: https://github.com/llvm/llvm-project/pull/95771.diff


1 Files Affected:

- (modified) llvm/lib/Analysis/BranchProbabilityInfo.cpp (+3-6) 


``````````diff
diff --git a/llvm/lib/Analysis/BranchProbabilityInfo.cpp b/llvm/lib/Analysis/BranchProbabilityInfo.cpp
index 50dcd5f45233f..3e9c60918f3c0 100644
--- a/llvm/lib/Analysis/BranchProbabilityInfo.cpp
+++ b/llvm/lib/Analysis/BranchProbabilityInfo.cpp
@@ -787,12 +787,9 @@ BranchProbabilityInfo::getInitialEstimatedBlockWeight(const BasicBlock *BB) {
                ? static_cast<uint32_t>(BlockExecWeight::NORETURN)
                : static_cast<uint32_t>(BlockExecWeight::UNREACHABLE);
 
-  // Check if the block is 'unwind' handler of  some invoke instruction.
-  for (const auto *Pred : predecessors(BB))
-    if (Pred)
-      if (const auto *II = dyn_cast<InvokeInst>(Pred->getTerminator()))
-        if (II->getUnwindDest() == BB)
-          return static_cast<uint32_t>(BlockExecWeight::UNWIND);
+  // Check if the block is an exception handling block.
+  if (BB->isEHPad())
+    return static_cast<uint32_t>(BlockExecWeight::UNWIND);
 
   // Check if the block contains 'cold' call.
   for (const auto &I : *BB)

``````````

</details>


https://github.com/llvm/llvm-project/pull/95771