Analyze shared memory alias (#81)

The purpose of this PR is analyzing shared memory aliases so that we can
fix memory allocation bugs and save memory allocations in triton code
involving complex control flows.

Changes to memory bar and allocation are on the way.

Co-authored-by: Philippe Tillet <phil@openai.com>

lib/Analysis/Utility.cpp

@@ -0,0 +1,38 @@
+#include "triton/Analysis/Utility.h"
+#include "mlir/IR/Dialect.h"
+#include "triton/Dialect/Triton/IR/Dialect.h"
+#include "triton/Dialect/TritonGPU/IR/Dialect.h"
+
+namespace mlir {
+
+bool isSharedEncoding(Value value) {
+  auto type = value.getType();
+  if (auto tensorType = type.dyn_cast<RankedTensorType>()) {
+    auto encoding = tensorType.getEncoding();
+    return encoding && encoding.isa<triton::gpu::SharedEncodingAttr>();
+  }
+  return false;
+}
+
+bool maybeSharedAllocationOp(Operation *op) {
+  // TODO(Keren): This function can be replaced by adding
+  // MemoryEffectOpInterface. We can then use the MemoryEffectOpInterface to
+  // query the memory effects of the op.
+  auto *dialect = op->getDialect();
+  return dialect &&
+         (dialect->getTypeID() ==
+              mlir::TypeID::get<triton::gpu::TritonGPUDialect>() ||
+          dialect->getTypeID() == mlir::TypeID::get<triton::TritonDialect>() ||
+          dialect->getTypeID() ==
+              mlir::TypeID::get<arith::ArithmeticDialect>());
+}
+
+std::string getValueOperandName(Value value, AsmState &state) {
+  auto *op = value.getDefiningOp();
+  std::string opName;
+  llvm::raw_string_ostream ss(opName);
+  value.printAsOperand(ss, state);
+  return std::move(opName);
+}
+
+} // namespace mlir