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tests: Added GTests for base/bitfield.hh

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In addition to the tests, a more detailed explanation of how
"insertBits(..)" functions has been included in its doxygen
documentation. The previous explanation was ambigious and led to
confusion.

Change-Id: I2ae8608733ebaa8f8f726cbb3a2cd8639b69c6b7
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21700
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
This commit is contained in:
Bobby R. Bruce
2019-10-10 16:02:46 -07:00
parent 5cd8bd6d48
commit 36e59917a7
3 changed files with 418 additions and 1 deletions
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1
src/base/SConscript
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@@ -37,6 +37,7 @@ SimObject('Graphics.py')
Source('atomicio.cc')
GTest('atomicio.test', 'atomicio.test.cc', 'atomicio.cc')
Source('bitfield.cc')
GTest('bitfield.test', 'bitfield.test.cc', 'bitfield.cc')
Source('imgwriter.cc')
Source('bmpwriter.cc')
Source('callback.cc')

9
src/base/bitfield.hh
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@@ -117,7 +117,14 @@ sext(uint64_t val)
}
/**
* Return val with bits first to last set to bit_val
* Returns val with bits first to last set to the LSBs of bit_val
*
* E.g.:
* first: 7
* last: 4
* val: 0xFFFF
* bit_val: 0x0000
* returned: 0xFF0F
*/
template <class T, class B>
inline

409
src/base/bitfield.test.cc Normal file
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@@ -0,0 +1,409 @@
/*
* Copyright (c) 2019 The Regents of the University of California
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* 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 the copyright holders 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.
*
* Authors: Bobby R. Bruce
*/
#include <gtest/gtest.h>
#include "base/bitfield.hh"
/*
* The following tests the "mask(N)" function. It is assumed that the mask
* returned is a 64 bit value with the N LSBs set to one.
*/
TEST(BitfieldTest, Mask0Bits)
{
EXPECT_EQ(0x0, mask(0));
}
TEST(BitfieldTest, Mask1Bit)
{
EXPECT_EQ(0x1, mask(1));
}
TEST(BitfieldTest, Mask8Bits)
{
EXPECT_EQ(0xFF, mask(8));
}
TEST(BitfieldTest, Mask16Bits)
{
EXPECT_EQ(0xFFFF, mask(16));
}
TEST(BitfieldTest, Mask32Bits)
{
EXPECT_EQ(0xFFFFFFFF, mask(32));
}
TEST(BitfieldTest, MaskAllBits)
{
EXPECT_EQ(0xFFFFFFFFFFFFFFFF, mask(64));
}
TEST(BitfieldTest, MaskAllBitsGreaterThan64)
{
/* We cannot create a mask greater than 64 bits. It should default to 64
* bits if this occurs.
*/
EXPECT_EQ(0xFFFFFFFFFFFFFFFF, mask(70));
}
/*
* The following tests "mask(X, Y)". mask will create a 64 bit value with bits
* X to Y (inclusive) set to one.
*/
TEST(BitfieldTest, MaskOneBit)
{
EXPECT_EQ(1, mask(0,0));
}
TEST(BitfieldTest, MaskTwoBits)
{
EXPECT_EQ((1 << 1) + 1, mask(1,0));
}
TEST(BitfieldTest, MaskThreeBits)
{
EXPECT_EQ((1 << 5) + (1 << 4) + (1 << 3), mask(5,3));
}
TEST(BitfieldTest, MaskEntireRange)
{
EXPECT_EQ(0xFFFFFFFFFFFFFFFF, mask(63,0));
}
TEST(BitfieldTest, MaskOutsideOfRange)
{
// Masking >64 bits is not possible. The maximum is a 64 bit mask.
EXPECT_EQ(0xFFFFFFFFFFFFFFFF, mask(100, 0));
}
/*
* The following tests "bits". This function extracts bit/bits from the input
* value and return them as the LSBs. The remaining bits are set to zero.
*/
TEST(BitfieldTest, ExtractOneBit)
{
int32_t x = 1 << 31;
EXPECT_EQ(1, bits(x, 31));
}
TEST(BitfieldTest, Extract63rdBit)
{
int64_t x = 1ULL << 63;
EXPECT_EQ(1, bits(x, 63));
}
TEST(BitfieldTest, ExtractFirstBit)
{
int64_t x = 1;
EXPECT_EQ(1, bits(x, 0));
}
TEST(BitfieldTest, ExtractFirstBitFirstBitZero)
{
int64_t x = 1 << 1;
EXPECT_EQ(0, bits(x, 0));
}
TEST(BitfieldTest, ExtractThreeBits)
{
uint64_t x = 1 << 31;
EXPECT_EQ((1 << 2), bits(x, 31, 29));
}
/*
* The following tests "mbits(X, Y, Z)". mbits returns a value with bits Y to
* Z from X (in position Y to Z).
*/
TEST(BitfieldTest, MbitsStandardCase)
{
uint64_t x = (1 << 10) + (1 << 1);
EXPECT_EQ((1 << 10), mbits(x, 10, 8));
}
TEST(BitfieldTest, MbitsEntireRange)
{
uint64_t x = (1ULL << 63) + 1;
EXPECT_EQ((1ULL << 63) + 1, mbits(x, 63, 0));
}
/*
* The following tests the "sext<N>(X)" function. sext carries out a sign
* extention from N bits to 64 bits on value X.
*/
TEST(BitfieldTest, SignExtendPositiveInput)
{
int8_t val = 14;
int64_t output = 14;
EXPECT_EQ(output, sext<8>(val));
}
TEST(BitfieldTest, SignExtendNegativeInput)
{
int8_t val = -14;
uint64_t output = -14;
EXPECT_EQ(output, sext<8>(val));
}
TEST(BitfieldTest, SignExtendPositiveInputOutsideRange)
{
EXPECT_EQ((1 << 10), sext<8>(1 << 10));
}
TEST(BitfieldTest, SignExtendNegativeInputOutsideRange)
{
uint64_t val = 0x4800000010000008;
uint64_t output = 0xF800000010000008;
EXPECT_EQ(output, sext<60>(val));
}
/* The following tests "insertBits(A, B, C, D)". insertBits returns A
* with bits B to C set to D's (B - C) LSBs. "insertBits(A, B, D)" overrides
* the function to insert only B's LSB to position B.
*/
TEST(BitfieldTest, InsertOneBitTo3)
{
int64_t val = 0;
int64_t bits = (1 << 3) + (1 << 2) + (1 << 1) + 1;
EXPECT_EQ((1 << 3), insertBits(val, 3, bits));
}
TEST(BitfieldTest, InsertOneBitTo18)
{
int64_t val = 0;
int64_t bits = (1 << 3) + (1 << 2) + (1 << 1) + 1;
EXPECT_EQ((1 << 18), insertBits(val, 18, bits));
}
TEST(BitfieldTest, InsertOneBitTo3LsbZero)
{
int64_t val = 0;
int64_t bits = (1 << 3) + (1 << 2) + (1 << 1);
EXPECT_EQ(0, insertBits(val, 3, bits));
}
TEST(BitfieldTest, InsertOneBitTo18LsbZero)
{
int64_t val = 0;
int64_t bits = (1 << 3) + (1 << 2) + (1 << 1);
EXPECT_EQ(0, insertBits(val, 18, bits));
}
TEST(BitfieldTest, InsertOnBitTo8LsbZero)
{
int64_t val = (1 << 8);
int64_t bits = (1 << 3) + (1 << 2) + (1 << 1);
EXPECT_EQ(0, insertBits(val, 8, bits));
}
TEST(BitfieldTest, InsertMultipleBits)
{
int64_t val = (1ULL << 63);
int64_t bits = (1 << 2) + 1;
EXPECT_EQ(val + (1 << 5) + (1 << 3), insertBits(val, 5, 3, bits));
}
TEST(BitfieldTest, InsertMultipleBitsOverwrite)
{
int64_t val = (1 << 29);
int64_t bits = (1 << 2) + 1;
EXPECT_EQ((1 << 30) + (1 << 28), insertBits(val, 30, 28, bits));
}
// The following tests the "reverseBits" function.
TEST(BitfieldTest, ReverseBits8Bit)
{
uint8_t value = (1 << 7);
EXPECT_EQ(1, reverseBits(value));
}
TEST(BitfieldTest, ReverseBits64Bit)
{
uint64_t value = 0xF0F0F0F0F0F0F0F1;
EXPECT_EQ(0x8F0F0F0F0F0F0F0F, reverseBits(value));
}
/* The following tests "findMsb" and "findLsb". These return the most position
* of the MSBs/LSBs of the input value.
*/
TEST(BitfieldTest, FindMsb29)
{
uint64_t val = (1 << 29) + (1 << 1);
EXPECT_EQ(29, findMsbSet(val));
}
TEST(BitfieldTest, FindMsb63)
{
uint64_t val = (1ULL << 63) + (1ULL << 60) + (1 << 1);
EXPECT_EQ(63, findMsbSet(val));
}
TEST(BitfieldTest, FindMsbZero)
{
EXPECT_EQ(0, findMsbSet(0));
}
TEST(BitfieldTest, FindLsb)
{
uint64_t val = (1ULL << 63) + (1 << 1);
EXPECT_EQ(1, findLsbSet(val));
}
TEST(BitfieldTest, FindLsbZero)
{
EXPECT_EQ(64, findLsbSet(0));
}
/* The following tests a simple function that verifies whether a value is a
* a power of two or not.
*/
TEST(BitfieldTest, IsPow2)
{
EXPECT_TRUE(isPow2(32));
}
TEST(BitfieldTest, IsNotPow2)
{
EXPECT_FALSE(isPow2(36));
}
TEST(BitfieldTest, IsPow2Zero)
{
EXPECT_TRUE(isPow2(0));
}
/*
* The following tests "popCount(X)". popCount counts the number of bits set to
* one.
*/
TEST(BitfieldTest, PopCountNoBits)
{
EXPECT_EQ(0, popCount(0));
}
TEST(BitfieldTest, PopCountOneBit)
{
int64_t val = (1 << 9);
EXPECT_EQ(1, popCount(val));
}
TEST(BitfieldTest, PopCountManyBits)
{
int64_t val = (1 << 22) + (1 << 21) + (1 << 15) + (1 << 9) + 1;
EXPECT_EQ(5, popCount(val));
}
TEST(BitfieldTest, PopCountAllOnes)
{
int64_t val = 0xFFFFFFFFFFFFFFFF;
EXPECT_EQ(64, popCount(val));
}
/*
* The following tests the "alignToPowerOfTwo(x)" function which rounds
* uint64_t x up to the nearest power of two. If x is already a power
* of two, that power is returned.
*/
TEST(BitfieldTest, AlignToPowerOfTwo0)
{
EXPECT_EQ(0, alignToPowerOfTwo(0));
}
TEST(BitfieldTest, AlignToPowerOfTwo3)
{
EXPECT_EQ(4, alignToPowerOfTwo(3));
}
TEST(BitfieldTest, AlignToPowerOfTwo5)
{
EXPECT_EQ(8, alignToPowerOfTwo(5));
}
TEST(BitfieldTest, AlignToPowerOfTwo10)
{
EXPECT_EQ(16, alignToPowerOfTwo(10));
}
TEST(BitfieldTest, AlignToPowerOfTwo16)
{
EXPECT_EQ(16, alignToPowerOfTwo(16));
}
TEST(BitfieldTest, AlignToPowerOfTwo31)
{
EXPECT_EQ(32, alignToPowerOfTwo(31));
}
/*
* The following tests test ctz32/64. The value returned in all cases should
* be equal to the number of trailing zeros (i.e., the number before the first
* bit set to one).
*/
TEST(BitfieldTest, CountTrailingZeros32BitsNoTrailing)
{
int32_t value = 1;
EXPECT_EQ(0, ctz32(value));
}
TEST(BitfieldTest, CountTrailingZeros32Bits)
{
uint32_t value = (1 << 30) + (1 << 29);
EXPECT_EQ(29, ctz32(value));
}
TEST(BitfieldTest, CountTrailingZeros64BitsNoTrailing)
{
uint64_t value = (1 << 29) + 1;
EXPECT_EQ(0, ctz64(value));
}
TEST(BitfieldTest, CountTrailingZeros64Bits)
{
uint64_t value = 1ULL << 63;
EXPECT_EQ(63, ctz64(value));
}
TEST(BitfieldTest, CountTrailingZero64AllZeros)
{
uint64_t value = 0;
EXPECT_EQ(64, ctz64(value));
}