[NFC] Use reference instead of copies in few places (#5118)

Apply fixes suggested by coverity static analysis.

Signed-off-by: Anatoly Myachev <[email protected]>

Author: anmyachev

include/triton/Analysis/AxisInfo.h

@@ -27,11 +27,12 @@ class AxisInfo {
 public:
   AxisInfo() : AxisInfo({}, {}, {}) {}
 
-  AxisInfo(DimVectorT contiguity, DimVectorT divisibility, DimVectorT constancy)
+  AxisInfo(ArrayRef<int64_t> contiguity, ArrayRef<int64_t> divisibility,
+           ArrayRef<int64_t> constancy)
       : AxisInfo(contiguity, divisibility, constancy, std::nullopt) {}
 
-  AxisInfo(DimVectorT contiguity, DimVectorT divisibility, DimVectorT constancy,
-           std::optional<int64_t> constantValue)
+  AxisInfo(ArrayRef<int64_t> contiguity, ArrayRef<int64_t> divisibility,
+           ArrayRef<int64_t> constancy, std::optional<int64_t> constantValue)
       : contiguity(contiguity), divisibility(divisibility),
         constancy(constancy), constantValue(constantValue) {
     assert(divisibility.size() == contiguity.size());

lib/Analysis/Allocation.cpp

@@ -84,8 +84,8 @@ ScratchConfig getScratchConfigForCvt(RankedTensorType srcTy,
 
   assert(cvtNeedsSharedMemory(srcTy, dstTy));
 
-  auto inOrd = gpu::getOrder(srcLayout);
-  auto outOrd = gpu::getOrder(dstLayout);
+  const auto &inOrd = gpu::getOrder(srcLayout);
+  const auto &outOrd = gpu::getOrder(dstLayout);
   scratchConfig.order = outOrd;
 
   unsigned srcContigPerThread =
@@ -303,7 +303,7 @@ class AllocationAnalysis {
   /// arguments are involved.
   void resolveAliasBufferLiveness(
       function_ref<Interval<size_t>(Value value)> getLiveness) {
-    for (auto aliasBufferIter : allocation->aliasBuffer) {
+    for (const auto &aliasBufferIter : allocation->aliasBuffer) {
       auto value = aliasBufferIter.first;
       auto buffers = aliasBufferIter.second;
       auto range = getLiveness(value);
@@ -443,7 +443,7 @@ class AllocationAnalysis {
           std::find_if(xBuffers.begin(), xBuffers.end(), [&](auto *buffer) {
             auto xRange = bufferRange[buffer];
             bool res = xRange.intersects(range);
-            for (auto val : tripleMap)
+            for (const auto &val : tripleMap)
               res = res &&
                     !val.second.intersects(xRange); // only one buffer intersect
             return res;

lib/Analysis/AxisInfo.cpp

@@ -1085,8 +1085,10 @@ LogicalResult AxisInfoAnalysis::visitOperation(
 void AxisInfoAnalysis::visitForOpInductionVar(
     scf::ForOp op, ArrayRef<dataflow::Lattice<AxisInfo> *> argLattices) {
   ProgramPoint *programPoint = getProgramPointAfter(op);
-  auto lb = getLatticeElementFor(programPoint, op.getLowerBound())->getValue();
-  auto step = getLatticeElementFor(programPoint, op.getStep())->getValue();
+  const auto &lb =
+      getLatticeElementFor(programPoint, op.getLowerBound())->getValue();
+  const auto &step =
+      getLatticeElementFor(programPoint, op.getStep())->getValue();
 
   AxisInfo::DimVectorT knownContiguity(1, 1);
   AxisInfo::DimVectorT knownDivisibility(1, 1);