[llvm] r321364 - [DAG] Integrate findBaseOffset address analyses to BaseIndexOffset. NFCI.
Nirav Dave via llvm-commits
llvm-commits at lists.llvm.org
Fri Dec 22 08:59:09 PST 2017
Author: niravd
Date: Fri Dec 22 08:59:09 2017
New Revision: 321364
URL: http://llvm.org/viewvc/llvm-project?rev=321364&view=rev
Log:
[DAG] Integrate findBaseOffset address analyses to BaseIndexOffset. NFCI.
BaseIndexOffset supercedes findBaseOffset analysis save only Constant
Pool addresses. Migrate analysis to BaseIndexOffset.
Modified:
llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=321364&r1=321363&r2=321364&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Fri Dec 22 08:59:09 2017
@@ -17405,43 +17405,6 @@ SDValue DAGCombiner::buildSqrtEstimate(S
return buildSqrtEstimateImpl(Op, Flags, false);
}
-/// Return true if base is a frame index, which is known not to alias with
-/// anything but itself. Provides base object and offset as results.
-static bool findBaseOffset(SDValue Ptr, SDValue &Base, int64_t &Offset,
- const GlobalValue *&GV, const void *&CV) {
- // Assume it is a primitive operation.
- Base = Ptr; Offset = 0; GV = nullptr; CV = nullptr;
-
- // If it's an adding a simple constant then integrate the offset.
- if (Base.getOpcode() == ISD::ADD) {
- if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Base.getOperand(1))) {
- Base = Base.getOperand(0);
- Offset += C->getSExtValue();
- }
- }
-
- // Return the underlying GlobalValue, and update the Offset. Return false
- // for GlobalAddressSDNode since the same GlobalAddress may be represented
- // by multiple nodes with different offsets.
- if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Base)) {
- GV = G->getGlobal();
- Offset += G->getOffset();
- return false;
- }
-
- // Return the underlying Constant value, and update the Offset. Return false
- // for ConstantSDNodes since the same constant pool entry may be represented
- // by multiple nodes with different offsets.
- if (ConstantPoolSDNode *C = dyn_cast<ConstantPoolSDNode>(Base)) {
- CV = C->isMachineConstantPoolEntry() ? (const void *)C->getMachineCPVal()
- : (const void *)C->getConstVal();
- Offset += C->getOffset();
- return false;
- }
- // If it's any of the following then it can't alias with anything but itself.
- return isa<FrameIndexSDNode>(Base);
-}
-
/// Return true if there is any possibility that the two addresses overlap.
bool DAGCombiner::isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1) const {
// If they are the same then they must be aliases.
@@ -17483,39 +17446,16 @@ bool DAGCombiner::isAlias(LSBaseSDNode *
return false;
}
- // FIXME: findBaseOffset and ConstantValue/GlobalValue/FrameIndex analysis
- // modified to use BaseIndexOffset.
-
- // Gather base node and offset information.
- SDValue Base0, Base1;
- int64_t Offset0, Offset1;
- const GlobalValue *GV0, *GV1;
- const void *CV0, *CV1;
- bool IsFrameIndex0 = findBaseOffset(Op0->getBasePtr(),
- Base0, Offset0, GV0, CV0);
- bool IsFrameIndex1 = findBaseOffset(Op1->getBasePtr(),
- Base1, Offset1, GV1, CV1);
-
- // If they have the same base address, then check to see if they overlap.
- if (Base0 == Base1 || (GV0 && (GV0 == GV1)) || (CV0 && (CV0 == CV1)))
- 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))
+ bool IsFI0 = isa<FrameIndexSDNode>(BasePtr0.getBase());
+ bool IsFI1 = isa<FrameIndexSDNode>(BasePtr1.getBase());
+ bool IsGV0 = isa<GlobalAddressSDNode>(BasePtr0.getBase());
+ bool IsGV1 = isa<GlobalAddressSDNode>(BasePtr1.getBase());
+ bool IsCV0 = isa<ConstantPoolSDNode>(BasePtr0.getBase());
+ bool IsCV1 = isa<ConstantPoolSDNode>(BasePtr1.getBase());
+
+ // Matched types are already handled above. So if this is true they
+ // cannot alias.
+ if ((IsFI0 || IsGV0 || IsCV0) && (IsFI1 || IsGV1 || IsCV1))
return false;
// If we know required SrcValue1 and SrcValue2 have relatively large alignment
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp?rev=321364&r1=321363&r2=321364&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp Fri Dec 22 08:59:09 2017
@@ -37,6 +37,23 @@ bool BaseIndexOffset::equalBaseIndex(Bas
return true;
}
+ // Match Constants
+ if (auto *A = dyn_cast<ConstantPoolSDNode>(Base))
+ if (auto *B = dyn_cast<ConstantPoolSDNode>(Other.Base)) {
+ bool IsMatch =
+ A->isMachineConstantPoolEntry() == B->isMachineConstantPoolEntry();
+ if (IsMatch) {
+ if (A->isMachineConstantPoolEntry())
+ IsMatch = A->getMachineCPVal() == B->getMachineCPVal();
+ else
+ IsMatch = A->getConstVal() == B->getConstVal();
+ }
+ if (IsMatch) {
+ Off += B->getOffset() - A->getOffset();
+ return true;
+ }
+ }
+
const MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
// Match non-equal FrameIndexes - If both frame indices are fixed
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