[llvm] r306498 - [DAG] Fold FrameIndex offset into BaseIndexOffset analysis. NFCI.
Nirav Dave via llvm-commits
llvm-commits at lists.llvm.org
Tue Jun 27 19:09:50 PDT 2017
Author: niravd
Date: Tue Jun 27 19:09:50 2017
New Revision: 306498
URL: http://llvm.org/viewvc/llvm-project?rev=306498&view=rev
Log:
[DAG] Fold FrameIndex offset into BaseIndexOffset analysis. NFCI.
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=306498&r1=306497&r2=306498&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/SelectionDAGAddressAnalysis.h (original)
+++ llvm/trunk/include/llvm/CodeGen/SelectionDAGAddressAnalysis.h Tue Jun 27 19:09:50 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=306498&r1=306497&r2=306498&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Tue Jun 27 19:09:50 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;
@@ -12394,7 +12394,7 @@ 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.
@@ -12414,8 +12414,8 @@ 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 {
@@ -12429,7 +12429,7 @@ 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
@@ -12443,7 +12443,7 @@ 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
@@ -12786,7 +12786,7 @@ 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()) {
@@ -16554,8 +16554,8 @@ 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));
@@ -16578,18 +16578,6 @@ bool DAGCombiner::isAlias(LSBaseSDNode *
return !((Offset0 + NumBytes0) <= Offset1 ||
(Offset1 + NumBytes1) <= Offset0);
- // It is possible for different frame indices to alias each other, mostly
- // when tail call optimization reuses return address slots for arguments.
- // To catch this case, look up the actual index of frame indices to compute
- // the real alias relationship.
- if (IsFrameIndex0 && IsFrameIndex1) {
- MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
- Offset0 += MFI.getObjectOffset(cast<FrameIndexSDNode>(Base0)->getIndex());
- Offset1 += MFI.getObjectOffset(cast<FrameIndexSDNode>(Base1)->getIndex());
- return !((Offset0 + NumBytes0) <= Offset1 ||
- (Offset1 + NumBytes1) <= Offset0);
- }
-
// Otherwise, if we know what the bases are, and they aren't identical, then
// we know they cannot alias.
if ((IsFrameIndex0 || CV0 || GV0) && (IsFrameIndex1 || CV1 || GV1))
@@ -16765,7 +16753,7 @@ 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())
@@ -16791,7 +16779,7 @@ 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=306498&r1=306497&r2=306498&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp Tue Jun 27 19:09:50 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"
@@ -26,20 +27,28 @@ bool BaseIndexOffset::equalBaseIndex(Bas
// Match GlobalAddresses
if (Index == Other.Index)
- if (GlobalAddressSDNode *A = dyn_cast<GlobalAddressSDNode>(Base))
- if (GlobalAddressSDNode *B = dyn_cast<GlobalAddressSDNode>(Other.Base))
+ 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.
+ // Match FrameIndexes
+ if (Index == Other.Index)
+ if (auto *A = dyn_cast<FrameIndexSDNode>(Base))
+ if (auto *B = dyn_cast<FrameIndexSDNode>(Other.Base)) {
+ const MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
+ 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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