From 609c9c142b23f1ffcbed4d804280bc812ed873d7 Mon Sep 17 00:00:00 2001
From: Jeremy Kun <j2kun@users.noreply.github.com>
Date: Thu, 9 Nov 2023 14:27:09 -0800
Subject: [PATCH] fixme: demonstrate solver integration works

---
 lib/Analysis/ReduceNoiseAnalysis/BUILD        |  2 +
 .../ReduceNoiseAnalysis.cpp                   | 43 ++++++++++++++++---
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/lib/Analysis/ReduceNoiseAnalysis/BUILD b/lib/Analysis/ReduceNoiseAnalysis/BUILD
index 8950234..90981d0 100644
--- a/lib/Analysis/ReduceNoiseAnalysis/BUILD
+++ b/lib/Analysis/ReduceNoiseAnalysis/BUILD
@@ -8,6 +8,8 @@ cc_library(
     hdrs = ["ReduceNoiseAnalysis.h"],
     deps = [
         "//lib/Dialect/Noisy",
+        "@com_google_ortools//ortools/base",
+        "@com_google_ortools//ortools/linear_solver",
         "@llvm-project//llvm:Support",
         "@llvm-project//mlir:IR",
     ],
diff --git a/lib/Analysis/ReduceNoiseAnalysis/ReduceNoiseAnalysis.cpp b/lib/Analysis/ReduceNoiseAnalysis/ReduceNoiseAnalysis.cpp
index 35e572b..c0cc1c1 100644
--- a/lib/Analysis/ReduceNoiseAnalysis/ReduceNoiseAnalysis.cpp
+++ b/lib/Analysis/ReduceNoiseAnalysis/ReduceNoiseAnalysis.cpp
@@ -2,17 +2,46 @@
 
 #include <string>
 
-#include "llvm/include/llvm/ADT/DenseMap.h"             // from @llvm-project
-#include "llvm/include/llvm/ADT/TypeSwitch.h"           // from @llvm-project
-#include "mlir/include/mlir/IR/Operation.h"             // from @llvm-project
-#include "mlir/include/mlir/IR/Value.h"                 // from @llvm-project
+#include "mlir/include/mlir/IR/Operation.h"
+#include "mlir/include/mlir/IR/Value.h"
+#include "ortools/linear_solver/linear_solver.h"
+#include "llvm/include/llvm/ADT/DenseMap.h"
+#include "llvm/include/llvm/ADT/TypeSwitch.h"
+
+using namespace operations_research;
 
 namespace mlir {
 namespace tutorial {
 
 ReduceNoiseAnalysis::ReduceNoiseAnalysis(Operation *op) {
-  // Implement analysis here
+  std::unique_ptr<MPSolver> solver(MPSolver::CreateSolver("SCIP"));
+
+  // Create the variables x and y.
+  MPVariable *const x = solver->MakeNumVar(0.0, 1, "x");
+  MPVariable *const y = solver->MakeNumVar(0.0, 2, "y");
+
+  LOG(INFO) << "Number of variables = " << solver->NumVariables();
+
+  // Create a linear constraint, 0 <= x + y <= 2.
+  MPConstraint *const ct = solver->MakeRowConstraint(0.0, 2.0, "ct");
+  ct->SetCoefficient(x, 1);
+  ct->SetCoefficient(y, 1);
+
+  LOG(INFO) << "Number of constraints = " << solver->NumConstraints();
+
+  // Create the objective function, 3 * x + y.
+  MPObjective *const objective = solver->MutableObjective();
+  objective->SetCoefficient(x, 3);
+  objective->SetCoefficient(y, 1);
+  objective->SetMaximization();
+
+  solver->Solve();
+
+  LOG(INFO) << "Solution:" << std::endl;
+  LOG(INFO) << "Objective value = " << objective->Value();
+  LOG(INFO) << "x = " << x->solution_value();
+  LOG(INFO) << "y = " << y->solution_value();
 }
 
-}  // namespace tutorial
-}  // namespace mlir
+} // namespace tutorial
+} // namespace mlir