[llvm] [LV] Vectorize uncountable early exit store loops with combined conditions (PR #205109)

[Graham Hunter via llvm-commits]

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@@ -1701,16 +1764,30 @@ bool LoopVectorizationLegality::isVectorizableEarlyExitLoop() {
   }
 
   // The latch block must have a countable exit.
-  if (isa<SCEVCouldNotCompute>(
-          PSE.getSE()->getPredicatedExitCount(TheLoop, LatchBB, &Predicates))) {
+  if (isa<SCEVCouldNotCompute>(PSE.getSE()->getPredicatedExitCount(
+          TheLoop, LatchBB, &Predicates, ScalarEvolution::SymbolicMaximum))) {
     reportVectorizationFailure(
         "Cannot determine exact exit count for latch block",
         "Cannot vectorize early exit loop",
         "UnknownLatchExitCountEarlyExitLoop", ORE, TheLoop);
     return false;
   }
-  assert(llvm::is_contained(CountableExitingBlocks, LatchBB) &&
-         "Latch block not found in list of countable exits!");
+
+  if (!is_contained(CountableExitingBlocks, LatchBB)) {
+    // If not a separate counted exit in the latch, then check for a combined
+    // countable and uncountable exit.
+    auto *Br = dyn_cast<CondBrInst>(LatchBB->getTerminator());
+    Value *CountableCond, *Ptr, *Other;
+    Instruction *Load;
+    if (!Br ||
+        !matchCombinedExitCondition(Br->getCondition(), CountableCond, Ptr,
+                                    Load, Other, *PSE.getSE(), TheLoop)) {
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huntergr-arm wrote:

Done.

https://github.com/llvm/llvm-project/pull/205109