[llvm] [VPlan] Dispatch to multiple exit blocks via middle blocks. (PR #112138)

[David Sherwood via llvm-commits]

================
@@ -1363,9 +1363,11 @@ class LoopVectorizationCostModel {
     // If we might exit from anywhere but the latch, must run the exiting
     // iteration in scalar form.
     if (TheLoop->getExitingBlock() != TheLoop->getLoopLatch()) {
-      LLVM_DEBUG(
-          dbgs() << "LV: Loop requires scalar epilogue: multiple exits\n");
-      return true;
+      if (!Legal->canVectorizeEarlyExit()) {
----------------
david-arm wrote:

I think you can fold the conditions together into a single if statement:

```
  if (!Legal->canVectorizeEarlyExit() && TheLoop->getExitingBlock() != TheLoop->getLoopLatch()) {
    ...
  }
```

https://github.com/llvm/llvm-project/pull/112138