[llvm] r276553 - [MSSA] Make EXPENSIVE_CHECKS check more.

[George Burgess IV via llvm-commits]

Author: gbiv
Date: Sun Jul 24 02:03:49 2016
New Revision: 276553

URL: http://llvm.org/viewvc/llvm-project?rev=276553&view=rev
Log:
[MSSA] Make EXPENSIVE_CHECKS check more.

checkClobberSanity will now be run for all results of `ClobberWalk`,
instead of just the crazy phi-optimized ones. This can help us catch
cases where our cache is being wonky.

Modified:
    llvm/trunk/lib/Transforms/Utils/MemorySSA.cpp

Modified: llvm/trunk/lib/Transforms/Utils/MemorySSA.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/MemorySSA.cpp?rev=276553&r1=276552&r2=276553&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/MemorySSA.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/MemorySSA.cpp Sun Jul 24 02:03:49 2016
@@ -236,9 +236,6 @@ checkClobberSanity(MemoryAccess *Start,
     return;
   }
 
-  assert((isa<MemoryPhi>(Start) || Start != ClobberAt) &&
-         "Start can't clobber itself!");
-
   bool FoundClobber = false;
   DenseSet<MemoryAccessPair> VisitedPhis;
   SmallVector<MemoryAccessPair, 8> Worklist;
@@ -818,22 +815,23 @@ public:
     // Fast path for the overly-common case (no crazy phi optimization
     // necessary)
     UpwardsWalkResult WalkResult = walkToPhiOrClobber(FirstDesc);
+    MemoryAccess *Result;
     if (WalkResult.IsKnownClobber) {
       cacheDefPath(FirstDesc, WalkResult.Result);
-      return WalkResult.Result;
+      Result = WalkResult.Result;
+    } else {
+      OptznResult OptRes = tryOptimizePhi(cast<MemoryPhi>(FirstDesc.Last),
+                                          Current, Q.StartingLoc);
+      verifyOptResult(OptRes);
+      cacheOptResult(OptRes);
+      resetPhiOptznState();
+      Result = OptRes.PrimaryClobber.Clobber;
     }
 
-    OptznResult OptRes =
-        tryOptimizePhi(cast<MemoryPhi>(FirstDesc.Last), Current, Q.StartingLoc);
-    verifyOptResult(OptRes);
-    cacheOptResult(OptRes);
-    resetPhiOptznState();
-
 #ifdef EXPENSIVE_CHECKS
-    checkClobberSanity(Current, OptRes.PrimaryClobber.Clobber, Q.StartingLoc,
-                       MSSA, Q, AA);
+    checkClobberSanity(Current, Result, Q.StartingLoc, MSSA, Q, AA);
 #endif
-    return OptRes.PrimaryClobber.Clobber;
+    return Result;
   }
 };