[llvm] r306688 - [DAG] Fold FrameIndex offset into BaseIndexOffset analysis. NFCI.
Nirav Dave via llvm-commits
llvm-commits at lists.llvm.org
Thu Jun 29 08:48:12 PDT 2017
Author: niravd
Date: Thu Jun 29 08:48:11 2017
New Revision: 306688
URL: http://llvm.org/viewvc/llvm-project?rev=306688&view=rev
Log:
[DAG] Fold FrameIndex offset into BaseIndexOffset analysis. NFCI.
Relanding after restricting equalBaseIndex to not erroneuosly consider
a FrameIndices stemming from alloca from being comparable as its
offset is set post-selectionDAG.
Pull FrameIndex comparision reasoning from DAGCombiner::isAlias to
general BaseIndexOffset.
Modified:
llvm/trunk/include/llvm/CodeGen/SelectionDAGAddressAnalysis.h
llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
Modified: llvm/trunk/include/llvm/CodeGen/SelectionDAGAddressAnalysis.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/SelectionDAGAddressAnalysis.h?rev=306688&r1=306687&r2=306688&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/SelectionDAGAddressAnalysis.h (original)
+++ llvm/trunk/include/llvm/CodeGen/SelectionDAGAddressAnalysis.h Thu Jun 29 08:48:11 2017
@@ -57,7 +57,7 @@ public:
int64_t &Off);
/// Parses tree in Ptr for base, index, offset addresses.
- static BaseIndexOffset match(SDValue Ptr);
+ static BaseIndexOffset match(SDValue Ptr, const SelectionDAG &DAG);
};
} // namespace llvm
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=306688&r1=306687&r2=306688&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Thu Jun 29 08:48:11 2017
@@ -4915,7 +4915,7 @@ SDValue DAGCombiner::MatchLoadCombine(SD
return SDValue();
// Loads must share the same base address
- BaseIndexOffset Ptr = BaseIndexOffset::match(L->getBasePtr());
+ BaseIndexOffset Ptr = BaseIndexOffset::match(L->getBasePtr(), DAG);
int64_t ByteOffsetFromBase = 0;
if (!Base)
Base = Ptr;
@@ -12442,7 +12442,7 @@ void DAGCombiner::getStoreMergeCandidate
StoreSDNode *St, SmallVectorImpl<MemOpLink> &StoreNodes) {
// This holds the base pointer, index, and the offset in bytes from the base
// pointer.
- BaseIndexOffset BasePtr = BaseIndexOffset::match(St->getBasePtr());
+ BaseIndexOffset BasePtr = BaseIndexOffset::match(St->getBasePtr(), DAG);
EVT MemVT = St->getMemoryVT();
// We must have a base and an offset.
@@ -12462,8 +12462,8 @@ void DAGCombiner::getStoreMergeCandidate
BaseIndexOffset LBasePtr;
// Match on loadbaseptr if relevant.
if (IsLoadSrc)
- LBasePtr =
- BaseIndexOffset::match(cast<LoadSDNode>(St->getValue())->getBasePtr());
+ LBasePtr = BaseIndexOffset::match(
+ cast<LoadSDNode>(St->getValue())->getBasePtr(), DAG);
auto CandidateMatch = [&](StoreSDNode *Other, BaseIndexOffset &Ptr,
int64_t &Offset) -> bool {
@@ -12477,7 +12477,7 @@ void DAGCombiner::getStoreMergeCandidate
if (IsLoadSrc) {
// The Load's Base Ptr must also match
if (LoadSDNode *OtherLd = dyn_cast<LoadSDNode>(Other->getValue())) {
- auto LPtr = BaseIndexOffset::match(OtherLd->getBasePtr());
+ auto LPtr = BaseIndexOffset::match(OtherLd->getBasePtr(), DAG);
if (!(LBasePtr.equalBaseIndex(LPtr, DAG)))
return false;
} else
@@ -12491,7 +12491,7 @@ void DAGCombiner::getStoreMergeCandidate
if (!(Other->getValue().getOpcode() == ISD::EXTRACT_VECTOR_ELT ||
Other->getValue().getOpcode() == ISD::EXTRACT_SUBVECTOR))
return false;
- Ptr = BaseIndexOffset::match(Other->getBasePtr());
+ Ptr = BaseIndexOffset::match(Other->getBasePtr(), DAG);
return (BasePtr.equalBaseIndex(Ptr, DAG, Offset));
};
// We looking for a root node which is an ancestor to all mergable
@@ -12834,7 +12834,7 @@ bool DAGCombiner::MergeConsecutiveStores
if (Ld->getMemoryVT() != MemVT)
break;
- BaseIndexOffset LdPtr = BaseIndexOffset::match(Ld->getBasePtr());
+ BaseIndexOffset LdPtr = BaseIndexOffset::match(Ld->getBasePtr(), DAG);
// If this is not the first ptr that we check.
int64_t LdOffset = 0;
if (LdBasePtr.getBase().getNode()) {
@@ -16602,8 +16602,8 @@ bool DAGCombiner::isAlias(LSBaseSDNode *
unsigned NumBytes1 = Op1->getMemoryVT().getSizeInBits() >> 3;
// Check for BaseIndexOffset matching.
- BaseIndexOffset BasePtr0 = BaseIndexOffset::match(Op0->getBasePtr());
- BaseIndexOffset BasePtr1 = BaseIndexOffset::match(Op1->getBasePtr());
+ BaseIndexOffset BasePtr0 = BaseIndexOffset::match(Op0->getBasePtr(), DAG);
+ BaseIndexOffset BasePtr1 = BaseIndexOffset::match(Op1->getBasePtr(), DAG);
int64_t PtrDiff;
if (BasePtr0.equalBaseIndex(BasePtr1, DAG, PtrDiff))
return !((NumBytes0 <= PtrDiff) || (PtrDiff + NumBytes1 <= 0));
@@ -16813,7 +16813,7 @@ SDValue DAGCombiner::FindBetterChain(SDN
bool DAGCombiner::findBetterNeighborChains(StoreSDNode *St) {
// This holds the base pointer, index, and the offset in bytes from the base
// pointer.
- BaseIndexOffset BasePtr = BaseIndexOffset::match(St->getBasePtr());
+ BaseIndexOffset BasePtr = BaseIndexOffset::match(St->getBasePtr(), DAG);
// We must have a base and an offset.
if (!BasePtr.getBase().getNode())
@@ -16839,7 +16839,7 @@ bool DAGCombiner::findBetterNeighborChai
break;
// Find the base pointer and offset for this memory node.
- BaseIndexOffset Ptr = BaseIndexOffset::match(Index->getBasePtr());
+ BaseIndexOffset Ptr = BaseIndexOffset::match(Index->getBasePtr(), DAG);
// Check that the base pointer is the same as the original one.
if (!BasePtr.equalBaseIndex(Ptr, DAG))
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp?rev=306688&r1=306687&r2=306688&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp Thu Jun 29 08:48:11 2017
@@ -11,6 +11,7 @@
#include "llvm/CodeGen/SelectionDAGAddressAnalysis.h"
#include "llvm/CodeGen/ISDOpcodes.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
@@ -18,28 +19,41 @@ namespace llvm {
bool BaseIndexOffset::equalBaseIndex(BaseIndexOffset &Other,
const SelectionDAG &DAG, int64_t &Off) {
- // Obvious equivalent
+ // Initial Offset difference.
Off = Other.Offset - Offset;
- if (Other.Base == Base && Other.Index == Index &&
- Other.IsIndexSignExt == IsIndexSignExt)
- return true;
-
- // Match GlobalAddresses
- if (Index == Other.Index)
- if (GlobalAddressSDNode *A = dyn_cast<GlobalAddressSDNode>(Base))
- if (GlobalAddressSDNode *B = dyn_cast<GlobalAddressSDNode>(Other.Base))
+
+ if ((Other.Index == Index) && (Other.IsIndexSignExt == IsIndexSignExt)) {
+ // Trivial match.
+ if (Other.Base == Base)
+ return true;
+
+ // Match GlobalAddresses
+ if (auto *A = dyn_cast<GlobalAddressSDNode>(Base))
+ if (auto *B = dyn_cast<GlobalAddressSDNode>(Other.Base))
if (A->getGlobal() == B->getGlobal()) {
Off += B->getOffset() - A->getOffset();
return true;
}
- // TODO: we should be able to add FrameIndex analysis improvements here.
+ const MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
+ // Match non-equal FrameIndexes - a FrameIndex stemming from an
+ // alloca will not have it's ObjectOffset set until post-DAG and
+ // as such we must assume the two framesIndices are incomparable.
+ if (auto *A = dyn_cast<FrameIndexSDNode>(Base))
+ if (auto *B = dyn_cast<FrameIndexSDNode>(Other.Base))
+ if (!MFI.getObjectAllocation(A->getIndex()) &&
+ !MFI.getObjectAllocation(B->getIndex())) {
+ Off += MFI.getObjectOffset(B->getIndex()) -
+ MFI.getObjectOffset(A->getIndex());
+ return true;
+ }
+ }
return false;
}
/// Parses tree in Ptr for base, index, offset addresses.
-BaseIndexOffset BaseIndexOffset::match(SDValue Ptr) {
+BaseIndexOffset BaseIndexOffset::match(SDValue Ptr, const SelectionDAG &DAG) {
// (((B + I*M) + c)) + c ...
SDValue Base = Ptr;
SDValue Index = SDValue();
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