intmath.test.cc

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/*
 * Copyright (c) 2019 The Regents of the University of California
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#include <gtest/gtest.h>

#include "base/intmath.hh"

TEST(IntmathTest, isPowerOf2)
{
    EXPECT_TRUE(isPowerOf2(1));
    EXPECT_TRUE(isPowerOf2(65536));
    EXPECT_TRUE(isPowerOf2(131072));
    EXPECT_TRUE(isPowerOf2(262144));
    EXPECT_FALSE(isPowerOf2(0));
    EXPECT_FALSE(isPowerOf2(2521));
    EXPECT_FALSE(isPowerOf2(1679616));
}

TEST(IntmathTest, power)
{
    EXPECT_EQ(65536, power(2, 16));
    EXPECT_EQ(9765625, power(5, 10));
    EXPECT_EQ(43046721, power(power(3, 4), 4));
}

TEST(IntmathTest, floorLog2)
{
    EXPECT_EQ(0, floorLog2(1));
    EXPECT_EQ(4, floorLog2(16));
    EXPECT_EQ(4, floorLog2(31));
    EXPECT_EQ(5, floorLog2(36));
    EXPECT_EQ(8, floorLog2(436));
    EXPECT_EQ(16, floorLog2(65537));
    EXPECT_EQ(20, floorLog2(1783592));
    EXPECT_EQ(41, floorLog2(2821109907456));

    // Test unsigned integers of various sizes.
    EXPECT_EQ(0, floorLog2((uint8_t)1));
    EXPECT_EQ(0, floorLog2((uint16_t)1));
    EXPECT_EQ(0, floorLog2((uint32_t)1));
    EXPECT_EQ(0, floorLog2((uint64_t)1));

    // Test signed integers of various sizes.
    EXPECT_EQ(0, floorLog2((int8_t)1));
    EXPECT_EQ(0, floorLog2((int16_t)1));
    EXPECT_EQ(0, floorLog2((int32_t)1));
    EXPECT_EQ(0, floorLog2((int64_t)1));
}

TEST(IntmathDeathTest, floorLog2)
{
    // Verify a non-positive input triggers an assert.
    EXPECT_DEATH_IF_SUPPORTED(floorLog2(0), "x > 0");
}

TEST(IntmathTest, ceilLog2)
{
    EXPECT_EQ(0, ceilLog2(1));
    EXPECT_EQ(4, ceilLog2(16));
    EXPECT_EQ(5, ceilLog2(31));
    EXPECT_EQ(6, ceilLog2(36));
    EXPECT_EQ(9, ceilLog2(436));
    EXPECT_EQ(17, ceilLog2(65537));
    EXPECT_EQ(21, ceilLog2(1783592));
    EXPECT_EQ(42, ceilLog2(2821109907456));
}


TEST(IntmathTest, divCeil)
{
    EXPECT_EQ(5, divCeil(55, 13));
    EXPECT_EQ(90, divCeil(7922, 89));
    EXPECT_EQ(4, divCeil(4800, 1442));
    EXPECT_EQ(4, divCeil(75, 24));
    EXPECT_EQ(46, divCeil(451, 10));
}

TEST(IntmathTest, roundUp)
{
    EXPECT_EQ(4104, roundUp(4101, 4));
    EXPECT_EQ(4112, roundUp(4105, 8));
    EXPECT_EQ(4112, roundUp(4101, 16));
    EXPECT_EQ(8192, roundUp(7991, 256));
}

TEST(IntmathTest, roundDown)
{
    EXPECT_EQ(4100, roundDown(4101, 4));
    EXPECT_EQ(4104, roundDown(4105, 8));
    EXPECT_EQ(4096, roundDown(4101, 16));
    EXPECT_EQ(7936, roundDown(7991, 256));
}