Fix SSAUpdaterImpl's RecordMatchingPHI to record exactly the

PHI nodes which were matched, rather than climbing up the
original PHI node's operands to rediscover PHI nodes for
recording, since the PHI nodes found that are not
necessarily part of the matched set.
This fixes rdar://10589171.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149654 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Transforms/Utils/SSAUpdaterImpl.h

@@ -380,7 +380,7 @@ public:
       if (!SomePHI)
         break;
       if (CheckIfPHIMatches(SomePHI)) {
-        RecordMatchingPHI(SomePHI);
+        RecordMatchingPHIs(BlockList);
         break;
       }
       // Match failed: clear all the PHITag values.
@@ -437,38 +437,17 @@ public:
     return true;
   }
 
-  /// RecordMatchingPHI - For a PHI node that matches, record it and its input
+  /// RecordMatchingPHIs - For each PHI node that matches, record it in both
-  /// PHIs in both the BBMap and the AvailableVals mapping.
+  /// the BBMap and the AvailableVals mapping.
-  void RecordMatchingPHI(PhiT *PHI) {
+  void RecordMatchingPHIs(BlockListTy *BlockList) {
-    SmallVector<PhiT*, 20> WorkList;
+    for (typename BlockListTy::iterator I = BlockList->begin(),
-    WorkList.push_back(PHI);
+           E = BlockList->end(); I != E; ++I)
-
+      if (PhiT *PHI = (*I)->PHITag) {
-    // Record this PHI.
+        BlkT *BB = PHI->getParent();
-    BlkT *BB = PHI->getParent();
+        ValT PHIVal = Traits::GetPHIValue(PHI);
-    ValT PHIVal = Traits::GetPHIValue(PHI);
+        (*AvailableVals)[BB] = PHIVal;
-    (*AvailableVals)[BB] = PHIVal;
+        BBMap[BB]->AvailableVal = PHIVal;
-    BBMap[BB]->AvailableVal = PHIVal;
-
-    while (!WorkList.empty()) {
-      PHI = WorkList.pop_back_val();
-
-      // Iterate through the PHI's incoming values.
-      for (typename Traits::PHI_iterator I = Traits::PHI_begin(PHI),
-             E = Traits::PHI_end(PHI); I != E; ++I) {
-        ValT IncomingVal = I.getIncomingValue();
-        PhiT *IncomingPHI = Traits::ValueIsPHI(IncomingVal, Updater);
-        if (!IncomingPHI) continue;
-        BB = IncomingPHI->getParent();
-        BBInfo *Info = BBMap[BB];
-        if (!Info || Info->AvailableVal)
-          continue;
-
-        // Record the PHI and add it to the worklist.
-        (*AvailableVals)[BB] = IncomingVal;
-        Info->AvailableVal = IncomingVal;
-        WorkList.push_back(IncomingPHI);
       }
-    }
   }
 };
 

test/Transforms/ScalarRepl/phi-cycle.ll

@@ -0,0 +1,77 @@
+; RUN: opt -S -scalarrepl-ssa < %s | FileCheck %s
+; rdar://10589171
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+%struct.foo = type { i32, i32 }
+
+@.str = private unnamed_addr constant [6 x i8] c"x=%d\0A\00", align 1
+
+define i32 @main(i32 %argc, i8** nocapture %argv) nounwind uwtable {
+entry:
+  %f = alloca %struct.foo, align 4
+  %x.i = getelementptr inbounds %struct.foo* %f, i64 0, i32 0
+  store i32 1, i32* %x.i, align 4
+  %y.i = getelementptr inbounds %struct.foo* %f, i64 0, i32 1
+  br label %while.cond.i
+
+; CHECK: while.cond.i:
+; CHECK-NEXT: %tmp = phi i32 [ 1, %entry ], [ %tmp2, %while.cond.backedge.i ]
+; CHECK-NEXT: %pos.0.i = phi i32 [ 1, %entry ], [ %xtmp.i, %while.cond.backedge.i ]
+; CHECK-NEXT: %left.0.i = phi i32 [ 1, %entry ], [ %dec.i, %while.cond.backedge.i ]
+; CHECK-NOT: phi
+while.cond.i:                                     ; preds = %while.cond.backedge.i, %entry
+  %tmp = phi i32 [ 1, %entry ], [ %tmp2, %while.cond.backedge.i ]
+  %pos.0.i = phi i32 [ 1, %entry ], [ %xtmp.i, %while.cond.backedge.i ]
+  %left.0.i = phi i32 [ 1, %entry ], [ %dec.i, %while.cond.backedge.i ]
+  %cmp.i = icmp sgt i32 %left.0.i, 0
+  br i1 %cmp.i, label %while.body.i, label %while.cond.i.func.exit_crit_edge
+
+while.cond.i.func.exit_crit_edge:                 ; preds = %while.cond.i
+  br label %func.exit
+
+while.body.i:                                     ; preds = %while.cond.i
+  %dec.i = add nsw i32 %left.0.i, -1
+  switch i32 1, label %while.body.i.func.exit_crit_edge [
+    i32 0, label %while.cond.backedge.i
+    i32 1, label %sw.bb.i
+  ]
+
+while.body.i.func.exit_crit_edge:                 ; preds = %while.body.i
+  br label %func.exit
+
+sw.bb.i:                                          ; preds = %while.body.i
+  %cmp2.i = icmp eq i32 %tmp, 1
+  br i1 %cmp2.i, label %if.then.i, label %if.end.i
+
+if.then.i:                                        ; preds = %sw.bb.i
+  store i32 %pos.0.i, i32* %x.i, align 4
+  br label %if.end.i
+
+; CHECK: if.end.i:
+; CHECK-NEXT: %tmp1 = phi i32 [ %pos.0.i, %if.then.i ], [ %tmp, %sw.bb.i ]
+; CHECK-NOT: phi
+if.end.i:                                         ; preds = %if.then.i, %sw.bb.i
+  %tmp1 = phi i32 [ %pos.0.i, %if.then.i ], [ %tmp, %sw.bb.i ]
+  store i32 %tmp1, i32* %y.i, align 4
+  br label %while.cond.backedge.i
+
+; CHECK: while.cond.backedge.i:
+; CHECK-NEXT: %tmp2 = phi i32 [ %tmp1, %if.end.i ], [ %tmp, %while.body.i ]
+; CHECK-NOT: phi
+while.cond.backedge.i:                            ; preds = %if.end.i, %while.body.i
+  %tmp2 = phi i32 [ %tmp1, %if.end.i ], [ %tmp, %while.body.i ]
+  %xtmp.i = add i32 %pos.0.i, 1
+  br label %while.cond.i
+
+; CHECK: func.exit:
+; CHECK-NOT: load
+; CHECK: %call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([6 x i8]* @.str, i64 0, i64 0), i32 %tmp) nounwind
+func.exit:                                        ; preds = %while.body.i.func.exit_crit_edge, %while.cond.i.func.exit_crit_edge
+  %tmp3 = load i32* %x.i, align 4
+  %call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([6 x i8]* @.str, i64 0, i64 0), i32 %tmp3) nounwind
+  ret i32 0
+}
+
+declare i32 @printf(i8* nocapture, ...) nounwind