diff --git a/internal/ceres/solver_impl_test.cc b/internal/ceres/solver_impl_test.cc
new file mode 100644
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+++ b/internal/ceres/solver_impl_test.cc
@@ -0,0 +1,479 @@
+// Ceres Solver - A fast non-linear least squares minimizer
+// Copyright 2010, 2011, 2012 Google Inc. All rights reserved.
+// http://code.google.com/p/ceres-solver/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// * Redistributions of source code must retain the above copyright notice,
+//   this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above copyright notice,
+//   this list of conditions and the following disclaimer in the documentation
+//   and/or other materials provided with the distribution.
+// * Neither the name of Google Inc. nor the names of its contributors may be
+//   used to endorse or promote products derived from this software without
+//   specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+//
+// Author: sameeragarwal@google.com (Sameer Agarwal)
+
+#include "gtest/gtest.h"
+#include "ceres/linear_solver.h"
+#include "ceres/parameter_block.h"
+#include "ceres/problem_impl.h"
+#include "ceres/program.h"
+#include "ceres/residual_block.h"
+#include "ceres/solver_impl.h"
+#include "ceres/sized_cost_function.h"
+
+
+namespace ceres {
+namespace internal {
+
+// Templated base class for the CostFunction signatures.
+template <int kNumResiduals, int N0, int N1, int N2>
+class MockCostFunctionBase : public
+SizedCostFunction<kNumResiduals, N0, N1, N2> {
+ public:
+  virtual bool Evaluate(double const* const* parameters,
+                        double* residuals,
+                        double** jacobians) const {
+    // Do nothing. This is never called.
+    return true;
+  }
+};
+
+class UnaryCostFunction : public MockCostFunctionBase<2, 1, 0, 0> {};
+class BinaryCostFunction : public MockCostFunctionBase<2, 1, 1, 0> {};
+class TernaryCostFunction : public MockCostFunctionBase<2, 1, 1, 1> {};
+
+TEST(SolverImpl, RemoveFixedBlocksNothingConstant) {
+  ProblemImpl problem;
+  double x;
+  double y;
+  double z;
+
+  problem.AddParameterBlock(&x, 1);
+  problem.AddParameterBlock(&y, 1);
+  problem.AddParameterBlock(&z, 1);
+  problem.AddResidualBlock(new UnaryCostFunction(), NULL, &x);
+  problem.AddResidualBlock(new BinaryCostFunction(), NULL, &x, &y);
+  problem.AddResidualBlock(new TernaryCostFunction(), NULL, &x, &y, &z);
+
+  string error;
+  {
+    int num_eliminate_blocks = 0;
+    Program program(*problem.mutable_program());
+    EXPECT_TRUE(SolverImpl::RemoveFixedBlocksFromProgram(&program,
+                                                         &num_eliminate_blocks,
+                                                         &error));
+    EXPECT_EQ(program.NumParameterBlocks(), 3);
+    EXPECT_EQ(program.NumResidualBlocks(), 3);
+    EXPECT_EQ(num_eliminate_blocks, 0);
+  }
+
+  // Check that num_eliminate_blocks is preserved, when it contains
+  // all blocks.
+  {
+    int num_eliminate_blocks = 3;
+    Program program(problem.program());
+    EXPECT_TRUE(SolverImpl::RemoveFixedBlocksFromProgram(&program,
+                                                         &num_eliminate_blocks,
+                                                         &error));
+    EXPECT_EQ(program.NumParameterBlocks(), 3);
+    EXPECT_EQ(program.NumResidualBlocks(), 3);
+    EXPECT_EQ(num_eliminate_blocks, 3);
+  }
+}
+
+TEST(SolverImpl, RemoveFixedBlocksAllParameterBlocksConstant) {
+  ProblemImpl problem;
+  double x;
+
+  problem.AddParameterBlock(&x, 1);
+  problem.AddResidualBlock(new UnaryCostFunction(), NULL, &x);
+  problem.SetParameterBlockConstant(&x);
+
+  int num_eliminate_blocks = 0;
+  Program program(problem.program());
+  string error;
+  EXPECT_TRUE(SolverImpl::RemoveFixedBlocksFromProgram(&program,
+                                                       &num_eliminate_blocks,
+                                                       &error));
+  EXPECT_EQ(program.NumParameterBlocks(), 0);
+  EXPECT_EQ(program.NumResidualBlocks(), 0);
+  EXPECT_EQ(num_eliminate_blocks, 0);
+}
+
+TEST(SolverImpl, RemoveFixedBlocksNoResidualBlocks) {
+  ProblemImpl problem;
+  double x;
+  double y;
+  double z;
+
+  problem.AddParameterBlock(&x, 1);
+  problem.AddParameterBlock(&y, 1);
+  problem.AddParameterBlock(&z, 1);
+
+  int num_eliminate_blocks = 0;
+  Program program(problem.program());
+  string error;
+  EXPECT_TRUE(SolverImpl::RemoveFixedBlocksFromProgram(&program,
+                                                       &num_eliminate_blocks,
+                                                       &error));
+  EXPECT_EQ(program.NumParameterBlocks(), 0);
+  EXPECT_EQ(program.NumResidualBlocks(), 0);
+  EXPECT_EQ(num_eliminate_blocks, 0);
+}
+
+TEST(SolverImpl, RemoveFixedBlocksOneParameterBlockConstant) {
+  ProblemImpl problem;
+  double x;
+  double y;
+  double z;
+
+  problem.AddParameterBlock(&x, 1);
+  problem.AddParameterBlock(&y, 1);
+  problem.AddParameterBlock(&z, 1);
+  problem.AddResidualBlock(new UnaryCostFunction(), NULL, &x);
+  problem.AddResidualBlock(new BinaryCostFunction(), NULL, &x, &y);
+  problem.SetParameterBlockConstant(&x);
+
+  int num_eliminate_blocks = 0;
+  Program program(problem.program());
+  string error;
+  EXPECT_TRUE(SolverImpl::RemoveFixedBlocksFromProgram(&program,
+                                                       &num_eliminate_blocks,
+                                                       &error));
+  EXPECT_EQ(program.NumParameterBlocks(), 1);
+  EXPECT_EQ(program.NumResidualBlocks(), 1);
+  EXPECT_EQ(num_eliminate_blocks, 0);
+}
+
+TEST(SolverImpl, RemoveFixedBlocksNumEliminateBlocks) {
+  ProblemImpl problem;
+  double x;
+  double y;
+  double z;
+
+  problem.AddParameterBlock(&x, 1);
+  problem.AddParameterBlock(&y, 1);
+  problem.AddParameterBlock(&z, 1);
+  problem.AddResidualBlock(new UnaryCostFunction(), NULL, &x);
+  problem.AddResidualBlock(new TernaryCostFunction(), NULL, &x, &y, &z);
+  problem.AddResidualBlock(new BinaryCostFunction(), NULL, &x, &y);
+  problem.SetParameterBlockConstant(&x);
+
+  int num_eliminate_blocks = 2;
+  Program program(problem.program());
+  string error;
+  EXPECT_TRUE(SolverImpl::RemoveFixedBlocksFromProgram(&program,
+                                                       &num_eliminate_blocks,
+                                                       &error));
+  EXPECT_EQ(program.NumParameterBlocks(), 2);
+  EXPECT_EQ(program.NumResidualBlocks(), 2);
+  EXPECT_EQ(num_eliminate_blocks, 1);
+}
+
+TEST(SolverImpl, ReorderResidualBlockNonSchurSolver) {
+  ProblemImpl problem;
+  double x;
+  double y;
+  double z;
+
+  problem.AddParameterBlock(&x, 1);
+  problem.AddParameterBlock(&y, 1);
+  problem.AddParameterBlock(&z, 1);
+  problem.AddResidualBlock(new UnaryCostFunction(), NULL, &x);
+  problem.AddResidualBlock(new TernaryCostFunction(), NULL, &x, &y, &z);
+  problem.AddResidualBlock(new BinaryCostFunction(), NULL, &x, &y);
+
+  const vector<ResidualBlock*>& residual_blocks =
+      problem.program().residual_blocks();
+  vector<ResidualBlock*> current_residual_blocks(residual_blocks);
+
+  Solver::Options options;
+  options.linear_solver_type = SPARSE_NORMAL_CHOLESKY;
+  string error;
+
+  EXPECT_TRUE(SolverImpl::MaybeReorderResidualBlocks(options,
+                                                     problem.mutable_program(),
+                                                     &error));
+  for (int i = 0; i < current_residual_blocks.size(); ++i) {
+    EXPECT_EQ(current_residual_blocks[i], residual_blocks[i]);
+  }
+}
+
+TEST(SolverImpl, ReorderResidualBlockNumEliminateBlockDeathTest) {
+  ProblemImpl problem;
+  double x;
+  double y;
+  double z;
+
+  problem.AddParameterBlock(&x, 1);
+  problem.AddParameterBlock(&y, 1);
+  problem.AddParameterBlock(&z, 1);
+  problem.AddResidualBlock(new UnaryCostFunction(), NULL, &x);
+  problem.AddResidualBlock(new TernaryCostFunction(), NULL, &x, &y, &z);
+  problem.AddResidualBlock(new BinaryCostFunction(), NULL, &x, &y);
+
+  Solver::Options options;
+  options.linear_solver_type = DENSE_SCHUR;
+  options.num_eliminate_blocks = 0;
+  string error;
+  EXPECT_DEATH(
+      SolverImpl::MaybeReorderResidualBlocks(
+          options, problem.mutable_program(), &error),
+      "Congratulations");
+}
+
+TEST(SolverImpl, ReorderResidualBlockNormalFunction) {
+  ProblemImpl problem;
+  double x;
+  double y;
+  double z;
+
+  problem.AddParameterBlock(&x, 1);
+  problem.AddParameterBlock(&y, 1);
+  problem.AddParameterBlock(&z, 1);
+
+  problem.AddResidualBlock(new UnaryCostFunction(), NULL, &x);
+  problem.AddResidualBlock(new BinaryCostFunction(), NULL, &z, &x);
+  problem.AddResidualBlock(new BinaryCostFunction(), NULL, &z, &y);
+  problem.AddResidualBlock(new UnaryCostFunction(), NULL, &z);
+  problem.AddResidualBlock(new BinaryCostFunction(), NULL, &x, &y);
+  problem.AddResidualBlock(new UnaryCostFunction(), NULL, &y);
+
+  Solver::Options options;
+  options.linear_solver_type = DENSE_SCHUR;
+  options.num_eliminate_blocks = 2;
+
+  const vector<ResidualBlock*>& residual_blocks =
+      problem.program().residual_blocks();
+
+  vector<ResidualBlock*> expected_residual_blocks;
+
+  // This is a bit fragile, but it serves the purpose. We know the
+  // bucketing algorithm that the reordering function uses, so we
+  // expect the order for residual blocks for each e_block to be
+  // filled in reverse.
+  expected_residual_blocks.push_back(residual_blocks[4]);
+  expected_residual_blocks.push_back(residual_blocks[1]);
+  expected_residual_blocks.push_back(residual_blocks[0]);
+  expected_residual_blocks.push_back(residual_blocks[5]);
+  expected_residual_blocks.push_back(residual_blocks[2]);
+  expected_residual_blocks.push_back(residual_blocks[3]);
+
+  Program* program = problem.mutable_program();
+  program->SetParameterOffsetsAndIndex();
+
+  string error;
+  EXPECT_TRUE(SolverImpl::MaybeReorderResidualBlocks(options,
+                                                     problem.mutable_program(),
+                                                     &error));
+  for (int i = 0; i < expected_residual_blocks.size(); ++i) {
+    EXPECT_EQ(residual_blocks[i], expected_residual_blocks[i]);
+  }
+}
+
+TEST(SolverImpl, ApplyUserOrderingOrderingTooSmall) {
+  ProblemImpl problem;
+  double x;
+  double y;
+  double z;
+
+  problem.AddParameterBlock(&x, 1);
+  problem.AddParameterBlock(&y, 1);
+  problem.AddParameterBlock(&z, 1);
+
+  vector<double*> ordering;
+  ordering.push_back(&x);
+  ordering.push_back(&z);
+
+  Program program(problem.program());
+  string error;
+  EXPECT_FALSE(SolverImpl::ApplyUserOrdering(problem,
+                                             ordering,
+                                             &program,
+                                             &error));
+}
+
+TEST(SolverImpl, ApplyUserOrderingHasDuplicates) {
+  ProblemImpl problem;
+  double x;
+  double y;
+  double z;
+
+  problem.AddParameterBlock(&x, 1);
+  problem.AddParameterBlock(&y, 1);
+  problem.AddParameterBlock(&z, 1);
+
+  vector<double*> ordering;
+  ordering.push_back(&x);
+  ordering.push_back(&z);
+  ordering.push_back(&z);
+
+  Program program(problem.program());
+  string error;
+  EXPECT_FALSE(SolverImpl::ApplyUserOrdering(problem,
+                                             ordering,
+                                             &program,
+                                             &error));
+}
+
+
+TEST(SolverImpl, ApplyUserOrderingNormal) {
+  ProblemImpl problem;
+  double x;
+  double y;
+  double z;
+
+  problem.AddParameterBlock(&x, 1);
+  problem.AddParameterBlock(&y, 1);
+  problem.AddParameterBlock(&z, 1);
+
+  vector<double*> ordering;
+  ordering.push_back(&x);
+  ordering.push_back(&z);
+  ordering.push_back(&y);
+
+  Program* program = problem.mutable_program();
+  string error;
+
+  EXPECT_TRUE(SolverImpl::ApplyUserOrdering(problem,
+                                            ordering,
+                                            program,
+                                            &error));
+  const vector<ParameterBlock*>& parameter_blocks = program->parameter_blocks();
+
+  EXPECT_EQ(parameter_blocks.size(), 3);
+  EXPECT_EQ(parameter_blocks[0]->user_state(), &x);
+  EXPECT_EQ(parameter_blocks[1]->user_state(), &z);
+  EXPECT_EQ(parameter_blocks[2]->user_state(), &y);
+}
+
+
+TEST(SolverImpl, CreateLinearSolverConjugateGradients) {
+  Solver::Options options;
+  options.linear_solver_type = CONJUGATE_GRADIENTS;
+  string error;
+  EXPECT_FALSE(SolverImpl::CreateLinearSolver(&options, &error));
+}
+
+#ifdef CERES_NO_SUITESPARSE
+TEST(SolverImpl, CreateLinearSolverNoSuiteSparse) {
+  Solver::Options options;
+  options.linear_solver_type = SPARSE_NORMAL_CHOLESKY;
+  string error;
+  EXPECT_FALSE(SolverImpl::CreateLinearSolver(&options, &error));
+}
+#endif  // CERES_NO_SUITESPARSE
+
+TEST(SolverImpl, CreateLinearSolverNegativeMaxNumIterations) {
+  Solver::Options options;
+  options.linear_solver_type = DENSE_QR;
+  options.linear_solver_max_num_iterations = -1;
+  string error;
+  EXPECT_EQ(SolverImpl::CreateLinearSolver(&options, &error),
+            static_cast<LinearSolver*>(NULL));
+}
+
+TEST(SolverImpl, CreateLinearSolverNegativeMinNumIterations) {
+  Solver::Options options;
+  options.linear_solver_type = DENSE_QR;
+  options.linear_solver_min_num_iterations = -1;
+  string error;
+  EXPECT_EQ(SolverImpl::CreateLinearSolver(&options, &error),
+            static_cast<LinearSolver*>(NULL));
+}
+
+TEST(SolverImpl, CreateLinearSolverMaxLessThanMinIterations) {
+  Solver::Options options;
+  options.linear_solver_type = DENSE_QR;
+  options.linear_solver_min_num_iterations = 10;
+  options.linear_solver_max_num_iterations = 5;
+  string error;
+  EXPECT_EQ(SolverImpl::CreateLinearSolver(&options, &error),
+            static_cast<LinearSolver*>(NULL));
+}
+
+TEST(SolverImpl, CreateLinearSolverZeroNumEliminateBlocks) {
+  Solver::Options options;
+  options.num_eliminate_blocks = 0;
+  options.linear_solver_type = DENSE_SCHUR;
+  string error;
+  scoped_ptr<LinearSolver> solver(
+      SolverImpl::CreateLinearSolver(&options, &error));
+  EXPECT_TRUE(solver != NULL);
+#ifndef CERES_NO_SUITESPARSE
+  EXPECT_EQ(options.linear_solver_type, SPARSE_NORMAL_CHOLESKY);
+#else
+  EXPECT_EQ(options.linear_solver_type, DENSE_QR);
+#endif  // CERES_NO_SUITESPARSE
+}
+
+TEST(SolverImpl, CreateLinearSolverDenseSchurMultipleThreads) {
+  Solver::Options options;
+  options.num_eliminate_blocks = 1;
+  options.linear_solver_type = DENSE_SCHUR;
+  options.num_linear_solver_threads = 2;
+  string error;
+  scoped_ptr<LinearSolver> solver(
+      SolverImpl::CreateLinearSolver(&options, &error));
+  EXPECT_TRUE(solver != NULL);
+  EXPECT_EQ(options.linear_solver_type, DENSE_SCHUR);
+  EXPECT_EQ(options.num_linear_solver_threads, 1);
+}
+
+TEST(SolverImpl, CreateLinearSolverNormalOperation) {
+  Solver::Options options;
+  scoped_ptr<LinearSolver> solver;
+  options.linear_solver_type = DENSE_QR;
+  string error;
+  solver.reset(SolverImpl::CreateLinearSolver(&options, &error));
+  EXPECT_EQ(options.linear_solver_type, DENSE_QR);
+  EXPECT_TRUE(solver.get() != NULL);
+
+#ifndef CERES_NO_SUITESPARSE
+  options.linear_solver_type = SPARSE_NORMAL_CHOLESKY;
+  solver.reset(SolverImpl::CreateLinearSolver(&options, &error));
+  EXPECT_EQ(options.linear_solver_type, SPARSE_NORMAL_CHOLESKY);
+  EXPECT_TRUE(solver.get() != NULL);
+#endif  // CERES_NO_SUITESPARSE
+
+  options.linear_solver_type = DENSE_SCHUR;
+  options.num_eliminate_blocks = 2;
+  solver.reset(SolverImpl::CreateLinearSolver(&options, &error));
+  EXPECT_EQ(options.linear_solver_type, DENSE_SCHUR);
+  EXPECT_TRUE(solver.get() != NULL);
+
+  options.linear_solver_type = SPARSE_SCHUR;
+  options.num_eliminate_blocks = 2;
+#ifndef CERES_NO_SUITESPARSE
+  solver.reset(SolverImpl::CreateLinearSolver(&options, &error));
+  EXPECT_TRUE(solver.get() != NULL);
+  EXPECT_EQ(options.linear_solver_type, SPARSE_SCHUR);
+#else   // CERES_NO_SUITESPARSE
+  EXPECT_TRUE(SolverImpl::CreateLinearSolver(&options, &error) == NULL);
+#endif  // CERES_NO_SUITESPARSE
+
+  options.linear_solver_type = ITERATIVE_SCHUR;
+  options.num_eliminate_blocks = 2;
+  solver.reset(SolverImpl::CreateLinearSolver(&options, &error));
+  EXPECT_EQ(options.linear_solver_type, ITERATIVE_SCHUR);
+  EXPECT_TRUE(solver.get() != NULL);
+}
+
+}  // namespace internal
+}  // namespace ceres