Fix PR12599.

The X86 target is editing the selection DAG while isel is selecting
nodes following a topological ordering. When the DAG hacking triggers
CSE, nodes can be deleted and bad things happen.

llvm-svn: 155257

llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp

@@ -2776,9 +2776,14 @@ SelectCodeCommon(SDNode *NodeToMatch, const unsigned char *MatcherTable,
                                                              (SDNode*) 0));
         }
 
-      } else {
+      } else if (NodeToMatch->getOpcode() != ISD::DELETED_NODE) {
         Res = MorphNode(NodeToMatch, TargetOpc, VTList, Ops.data(), Ops.size(),
                         EmitNodeInfo);
+      } else {
+        // NodeToMatch was eliminated by CSE when the target changed the DAG.
+        // We will visit the equivalent node later.
+        DEBUG(dbgs() << "Node was eliminated by CSE\n");
+        return 0;
       }
 
       // If the node had chain/glue results, update our notion of the current

llvm/test/CodeGen/X86/selectiondag-cse.ll

@@ -0,0 +1,69 @@
+; RUN: llc < %s
+; PR12599
+;
+; This bitcode causes the X86 target to make changes to the DAG during
+; selection in MatchAddressRecursively. The edit triggers CSE which causes both
+; the current node and yet-to-be-selected nodes to be deleted.
+;
+; SelectionDAGISel::DoInstructionSelection must handle that.
+;
+target triple = "x86_64-apple-macosx"
+
+%0 = type { i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, float, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i8**, i8**, i32, i32***, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [9 x [16 x [16 x i16]]], [5 x [16 x [16 x i16]]], [9 x [8 x [8 x i16]]], [2 x [4 x [16 x [16 x i16]]]], [16 x [16 x i16]], [16 x [16 x i32]], i32****, i32***, i32***, i32***, i32****, i32****, %1*, %2*, %9*, i32*, i32*, i32, i32, i32, i32, [4 x [4 x i32]], i32, i32, i32, i32, i32, double, i32, i32, i32, i32, i16******, i16******, i16******, i16******, [15 x i16], i32, i32, i32, i32, i32, i32, i32, i32, [6 x [32 x i32]], i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [1 x i32], i32, i32, [2 x i32], i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, %10*, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, double**, double***, i32***, double**, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [3 x [2 x i32]], [2 x i32], i32, i32, i16, i32, i32, i32, i32, i32 }
+%1 = type { i32, i32, [100 x %2*], i32, float, float, float }
+%2 = type { i32, i32, i32, i32, i32, i32, %3*, %6*, %8*, i32, i32*, i32*, i32*, i32, i32*, i32*, i32*, i32 (i32)*, [3 x [2 x i32]] }
+%3 = type { %4*, %5, %5 }
+%4 = type { i32, i32, i8, i32, i32, i8, i8, i32, i32, i8*, i32 }
+%5 = type { i32, i32, i32, i32, i32, i8*, i32*, i32, i32 }
+%6 = type { [3 x [11 x %7]], [2 x [9 x %7]], [2 x [10 x %7]], [2 x [6 x %7]], [4 x %7], [4 x %7], [3 x %7] }
+%7 = type { i16, i8, i64 }
+%8 = type { [2 x %7], [4 x %7], [3 x [4 x %7]], [10 x [4 x %7]], [10 x [15 x %7]], [10 x [15 x %7]], [10 x [5 x %7]], [10 x [5 x %7]], [10 x [15 x %7]], [10 x [15 x %7]] }
+%9 = type { i32, i32, i32, [2 x i32], i32, [8 x i32], %9*, %9*, i32, [2 x [4 x [4 x [2 x i32]]]], [16 x i8], [16 x i8], i32, i64, [4 x i32], [4 x i32], i64, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i16, double, i32, i32, i32, i32, i32, i32, i32, i32, i32 }
+%10 = type { i32, i32, i32, i32, i32, %10* }
+
+@images = external hidden global %0, align 8
+
+define hidden fastcc void @Mode_Decision_for_4x4IntraBlocks() nounwind uwtable ssp {
+bb4:
+  %tmp = or i208 undef, 0
+  br i1 undef, label %bb35, label %bb5
+
+bb5:
+  %tmp6 = add i32 0, 2
+  %tmp7 = lshr i208 %tmp, 80
+  %tmp8 = trunc i208 %tmp7 to i32
+  %tmp9 = and i32 %tmp8, 65535
+  %tmp10 = shl nuw nsw i32 %tmp9, 1
+  %tmp11 = add i32 0, 2
+  %tmp12 = add i32 %tmp11, 0
+  %tmp13 = add i32 %tmp12, %tmp10
+  %tmp14 = lshr i32 %tmp13, 2
+  %tmp15 = trunc i32 %tmp14 to i16
+  store i16 %tmp15, i16* getelementptr inbounds (%0* @images, i64 0, i32 47, i64 3, i64 0, i64 3), align 2
+  %tmp16 = lshr i208 %tmp, 96
+  %tmp17 = trunc i208 %tmp16 to i32
+  %tmp18 = and i32 %tmp17, 65535
+  %tmp19 = add i32 %tmp18, 2
+  %tmp20 = add i32 %tmp19, 0
+  %tmp21 = add i32 %tmp20, 0
+  %tmp22 = lshr i32 %tmp21, 2
+  %tmp23 = trunc i32 %tmp22 to i16
+  store i16 %tmp23, i16* getelementptr inbounds (%0* @images, i64 0, i32 47, i64 3, i64 2, i64 3), align 2
+  %tmp24 = add i32 %tmp6, %tmp9
+  %tmp25 = add i32 %tmp24, 0
+  %tmp26 = lshr i32 %tmp25, 2
+  %tmp27 = trunc i32 %tmp26 to i16
+  store i16 %tmp27, i16* getelementptr inbounds (%0* @images, i64 0, i32 47, i64 7, i64 1, i64 2), align 4
+  %tmp28 = lshr i208 %tmp, 80
+  %tmp29 = shl nuw nsw i208 %tmp28, 1
+  %tmp30 = trunc i208 %tmp29 to i32
+  %tmp31 = and i32 %tmp30, 131070
+  %tmp32 = add i32 %tmp12, %tmp31
+  %tmp33 = lshr i32 %tmp32, 2
+  %tmp34 = trunc i32 %tmp33 to i16
+  store i16 %tmp34, i16* getelementptr inbounds (%0* @images, i64 0, i32 47, i64 7, i64 1, i64 3), align 2
+  br label %bb35
+
+bb35:                                             ; preds = %bb5, %bb4
+  unreachable
+}