[llvm] [PseudoProbe] Extend to skip instrumenting probe into the dests of invoke (PR #79919)

[via llvm-commits]

================
@@ -173,20 +173,49 @@ SampleProfileProber::SampleProfileProber(Function &Func,
   BlockProbeIds.clear();
   CallProbeIds.clear();
   LastProbeId = (uint32_t)PseudoProbeReservedId::Last;
-  computeProbeIdForBlocks();
+
+  DenseSet<BasicBlock *> InvokeNormalDests;
+  findInvokeNormalDests(InvokeNormalDests);
+  DenseSet<BasicBlock *> KnownColdBlocks;
+  computeEHOnlyBlocks(*F, KnownColdBlocks);
+
+  computeProbeIdForBlocks(InvokeNormalDests, KnownColdBlocks);
   computeProbeIdForCallsites();
-  computeCFGHash();
+  computeCFGHash(InvokeNormalDests, KnownColdBlocks);
+}
+
+void SampleProfileProber::findInvokeNormalDests(
+    DenseSet<BasicBlock *> &InvokeNormalDests) {
+  for (auto &BB : *F) {
+    auto *TI = BB.getTerminator();
+    if (auto *II = dyn_cast<InvokeInst>(TI))
+      InvokeNormalDests.insert(II->getNormalDest());
+  }
 }
 
 // Compute Hash value for the CFG: the lower 32 bits are CRC32 of the index
 // value of each BB in the CFG. The higher 32 bits record the number of edges
 // preceded by the number of indirect calls.
 // This is derived from FuncPGOInstrumentation<Edge, BBInfo>::computeCFGHash().
-void SampleProfileProber::computeCFGHash() {
+void SampleProfileProber::computeCFGHash(
+    const DenseSet<BasicBlock *> &InvokeNormalDests,
+    const DenseSet<BasicBlock *> &KnownColdBlocks) {
   std::vector<uint8_t> Indexes;
   JamCRC JC;
   for (auto &BB : *F) {
-    for (BasicBlock *Succ : successors(&BB)) {
+    // Skip the EH flow blocks.
+    if (InvokeNormalDests.contains(&BB) || KnownColdBlocks.contains(&BB))
+      continue;
+
+    // Find the original successors by skipping the EH flow succs.
+    auto *BBPtr = &BB;
+    auto *TI = BBPtr->getTerminator();
+    while (auto *II = dyn_cast<InvokeInst>(TI)) {
+      BBPtr = II->getNormalDest();
+      TI = BBPtr->getTerminator();
+    }
----------------
WenleiHe wrote:

IIUC, this loop skips the Invoke normal dest as successor. Can we simply skip such successors in the loop below on line 218? I think `getBlockId(Succ)` will be zero for these cases and we can just check and skip? 

By doing that, we will be ignoring 1) all edges from `BlocksToIgnore` due to check on line 207; 2) all edges into `BlocksToIgnore` due to a new check `getBlockId(Succ) != 0`. That should be all we need? 

https://github.com/llvm/llvm-project/pull/79919