Add a new optimization pass: Stack Coloring, that merges disjoint static allocations (allocas). Allocas are known to be
disjoint if they are marked by disjoint lifetime markers (@llvm.lifetime.XXX intrinsics).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163299 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 31d633c..b587884 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -19,6 +19,7 @@
#include "llvm/ADT/SmallSet.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Constants.h"
#include "llvm/CallingConv.h"
#include "llvm/DebugInfo.h"
@@ -5215,14 +5216,30 @@
rw==1)); /* write */
return 0;
}
-
- case Intrinsic::invariant_start:
case Intrinsic::lifetime_start:
+ case Intrinsic::lifetime_end: {
+ SDValue Ops[2];
+ AllocaInst *LifetimeObject =dyn_cast_or_null<AllocaInst>(
+ GetUnderlyingObject(I.getArgOperand(1), TD));
+ // Could not find an Alloca.
+ if (!LifetimeObject)
+ 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);
+
+ Res = DAG.getNode(Opcode, dl, MVT::Other, Ops, 2);
+ DAG.setRoot(Res);
+ return 0;
+ }
+ case Intrinsic::invariant_start:
// Discard region information.
setValue(&I, DAG.getUNDEF(TLI.getPointerTy()));
return 0;
case Intrinsic::invariant_end:
- case Intrinsic::lifetime_end:
// Discard region information.
return 0;
case Intrinsic::donothing: