Teach the DAGBuilder about lifetime markers which are generated from PHINodes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163494 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 57 insertions, 18 deletions

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 1eb251d0a6..483b051bdc 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5218,28 +5218,32 @@ SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) {
   }
   case Intrinsic::lifetime_start:
   case Intrinsic::lifetime_end: {
+    bool IsStart = (Intrinsic == Intrinsic::lifetime_start);
     // Stack coloring is not enabled in O0, discard region information.
-    if (TM.getOptLevel() == CodeGenOpt::None) {
-      if (Intrinsic == Intrinsic::lifetime_start)
-        setValue(&I, DAG.getUNDEF(TLI.getPointerTy()));
-      return 0;
-    }
-    SDValue Ops[2];
-    AllocaInst *LifetimeObject =dyn_cast_or_null<AllocaInst>(
-                                   GetUnderlyingObject(I.getArgOperand(1), TD));
-    // Could not find an Alloca.
-    if (!LifetimeObject)
+    if (TM.getOptLevel() == CodeGenOpt::None)
       return 0;
 
-    int FI = FuncInfo.StaticAllocaMap[LifetimeObject];
-    Ops[0] = getRoot();
-    Ops[1] = DAG.getFrameIndex(FI, TLI.getPointerTy(), true);
-    bool IsStart = (Intrinsic == Intrinsic::lifetime_start);
-    unsigned Opcode = (IsStart ? ISD::LIFETIME_START : ISD::LIFETIME_END);
+    SmallVector<Value *, 4> Allocas;
+    GetUnderlyingObjects(I.getArgOperand(1), Allocas, TD);
 
-    Res = DAG.getNode(Opcode, dl, MVT::Other, Ops, 2);
-    DAG.setRoot(Res);
-    return 0;
+    for (SmallVector<Value*, 4>::iterator Object = Allocas.begin(),
+         E = Allocas.end(); Object != E; ++Object) {
+      AllocaInst *LifetimeObject = dyn_cast_or_null<AllocaInst>(*Object);
+
+      // Could not find an Alloca.
+      if (!LifetimeObject)
+        continue;
+
+      int FI = FuncInfo.StaticAllocaMap[LifetimeObject];
+
+      SDValue Ops[2];
+      Ops[0] = getRoot();
+      Ops[1] = DAG.getFrameIndex(FI, TLI.getPointerTy(), true);
+      unsigned Opcode = (IsStart ? ISD::LIFETIME_START : ISD::LIFETIME_END);
+
+      Res = DAG.getNode(Opcode, dl, MVT::Other, Ops, 2);
+      DAG.setRoot(Res);
+    }
   }
   case Intrinsic::invariant_start:
     // Discard region information.
diff --git a/test/CodeGen/X86/StackColoring.ll b/test/CodeGen/X86/StackColoring.ll
index 26ed0ecc0c..42235a03e3 100644
--- a/test/CodeGen/X86/StackColoring.ll
+++ b/test/CodeGen/X86/StackColoring.ll
@@ -262,6 +262,41 @@ entry:
   ret void
 }
 
+;YESCOLOR: subq  $272, %rsp
+;NOCOLOR: subq  $272, %rsp
+define i32 @func_phi_lifetime(i32 %in, i1 %d) {
+entry:
+  %a = alloca [17 x i8*], align 8
+  %a2 = alloca [16 x i8*], align 8
+  %b = bitcast [17 x i8*]* %a to i8*
+  %b2 = bitcast [16 x i8*]* %a2 to i8*
+  %t1 = call i32 @foo(i32 %in, i8* %b)
+  %t2 = call i32 @foo(i32 %in, i8* %b)
+  call void @llvm.lifetime.end(i64 -1, i8* %b)
+  br i1 %d, label %bb0, label %bb1
+
+bb0:
+  %I1 = bitcast [17 x i8*]* %a to i8*
+  br label %bb2
+
+bb1:
+  %I2 = bitcast [16 x i8*]* %a2 to i8*
+  br label %bb2
+
+bb2:
+  %split = phi i8* [ %I1, %bb0 ], [ %I2, %bb1 ]
+  call void @llvm.lifetime.start(i64 -1, i8* %split)
+  %t3 = call i32 @foo(i32 %in, i8* %b2)
+  %t4 = call i32 @foo(i32 %in, i8* %b2)
+  %t5 = add i32 %t1, %t2
+  %t6 = add i32 %t3, %t4
+  %t7 = add i32 %t5, %t6
+  call void @llvm.lifetime.end(i64 -1, i8* %split)
+  ret i32 %t7
+bb3:
+  ret i32 0
+}
+
 declare void @bar([100 x i32]* , [100 x i32]*) nounwind
 
 declare void @llvm.lifetime.start(i64, i8* nocapture) nounwind