/*

* Copyright (c) Facebook, Inc. and its affiliates.

*

* This source code is licensed under the MIT license found in the

* LICENSE file in the root directory of this source tree.

*/

#include "llvh/Support/Casting.h"

#include "llvh/Support/SourceMgr.h"

#include "llvh/Support/YAMLParser.h"

#include "hermes/AST/Context.h"

#include "hermes/BCGen/RegAlloc.h"

#include "gtest/gtest.h"

using namespace hermes;

namespace {

TEST(RegisterAllocatorTest, RegisterFileTest) {

RegisterFile File;

// We are starting with an empty register file.

EXPECT_EQ(File.getNumLiveRegisters(), 0u);

EXPECT_EQ(File.getMaxRegisterUsage(), 0u);

// Allocate a few registers.

Register R1 = File.allocateRegister();

Register R2 = File.allocateRegister();

Register R3 = File.allocateRegister();

// Make sure we know which registers are alive.

EXPECT_EQ(File.getMaxRegisterUsage(), 3u);

EXPECT_TRUE(File.isUsed(R1));

EXPECT_TRUE(File.isUsed(R2));

EXPECT_TRUE(File.isUsed(R3));

EXPECT_FALSE(File.isFree(R1));

EXPECT_FALSE(File.isFree(R2));

EXPECT_FALSE(File.isFree(R3));

EXPECT_EQ(File.getMaxRegisterUsage(), 3u);

// Make sure we can kill registers and things keep working.

File.killRegister(R2);

EXPECT_TRUE(File.isUsed(R1));

EXPECT_FALSE(File.isUsed(R2));

EXPECT_TRUE(File.isUsed(R3));

EXPECT_TRUE(File.isFree(R2));

// Make sure we can reuse the freed register.

Register R4 = File.allocateRegister();

EXPECT_EQ(File.getMaxRegisterUsage(), 3u);

File.killRegister(R1);

File.killRegister(R3);

File.killRegister(R4);

// Make sure that all registers have been freed.

EXPECT_EQ(File.getNumLiveRegisters(), 0u);

// Make sure we can allocate lots of registers and free them in some order.

std::vector<Register> regs;

for (int i = 0; i < 1000; i++) {

regs.push_back(File.allocateRegister());

}

for (auto &R : regs) {

File.killRegister(R);

}

// Make sure that all registers have been freed again.

EXPECT_EQ(File.getNumLiveRegisters(), 0u);

}

} // end anonymous namespace