From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- mfbt/tests/TestWrappingOperations.cpp | 587 ++++++++++++++++++++++++++++++++++ 1 file changed, 587 insertions(+) create mode 100644 mfbt/tests/TestWrappingOperations.cpp (limited to 'mfbt/tests/TestWrappingOperations.cpp') diff --git a/mfbt/tests/TestWrappingOperations.cpp b/mfbt/tests/TestWrappingOperations.cpp new file mode 100644 index 0000000000..c1cbb8ae6a --- /dev/null +++ b/mfbt/tests/TestWrappingOperations.cpp @@ -0,0 +1,587 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this file, + * You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "mozilla/Assertions.h" +#include "mozilla/WrappingOperations.h" + +#include + +using mozilla::WrappingAdd; +using mozilla::WrappingMultiply; +using mozilla::WrappingSubtract; +using mozilla::WrapToSigned; + +// NOTE: In places below |-FOO_MAX - 1| is used instead of |-FOO_MIN| because +// in C++ numeric literals are full expressions -- the |-| in a negative +// number is technically separate. So with most compilers that limit +// |int| to the signed 32-bit range, something like |-2147483648| is +// operator-() applied to an *unsigned* expression. And MSVC, at least, +// warns when you do that. (The operation is well-defined, but it likely +// doesn't do what was intended.) So we do the usual workaround for this +// (see your local copy of for a likely demo of this), writing +// it out by negating the max value and subtracting 1. + +static_assert(WrapToSigned(uint8_t(17)) == 17, + "no wraparound should work, 8-bit"); +static_assert(WrapToSigned(uint8_t(128)) == -128, + "works for 8-bit numbers, wraparound low end"); +static_assert(WrapToSigned(uint8_t(128 + 7)) == -128 + 7, + "works for 8-bit numbers, wraparound mid"); +static_assert(WrapToSigned(uint8_t(128 + 127)) == -128 + 127, + "works for 8-bit numbers, wraparound high end"); + +static_assert(WrapToSigned(uint16_t(12345)) == 12345, + "no wraparound should work, 16-bit"); +static_assert(WrapToSigned(uint16_t(32768)) == -32768, + "works for 16-bit numbers, wraparound low end"); +static_assert(WrapToSigned(uint16_t(32768 + 42)) == -32768 + 42, + "works for 16-bit numbers, wraparound mid"); +static_assert(WrapToSigned(uint16_t(32768 + 32767)) == -32768 + 32767, + "works for 16-bit numbers, wraparound high end"); + +static_assert(WrapToSigned(uint32_t(8675309)) == 8675309, + "no wraparound should work, 32-bit"); +static_assert(WrapToSigned(uint32_t(2147483648)) == -2147483647 - 1, + "works for 32-bit numbers, wraparound low end"); +static_assert(WrapToSigned(uint32_t(2147483648 + 42)) == -2147483647 - 1 + 42, + "works for 32-bit numbers, wraparound mid"); +static_assert(WrapToSigned(uint32_t(2147483648 + 2147483647)) == + -2147483647 - 1 + 2147483647, + "works for 32-bit numbers, wraparound high end"); + +static_assert(WrapToSigned(uint64_t(4152739164)) == 4152739164, + "no wraparound should work, 64-bit"); +static_assert(WrapToSigned(uint64_t(9223372036854775808ULL)) == + -9223372036854775807LL - 1, + "works for 64-bit numbers, wraparound low end"); +static_assert(WrapToSigned(uint64_t(9223372036854775808ULL + 8005552368LL)) == + -9223372036854775807LL - 1 + 8005552368LL, + "works for 64-bit numbers, wraparound mid"); +static_assert(WrapToSigned(uint64_t(9223372036854775808ULL + + 9223372036854775807ULL)) == + -9223372036854775807LL - 1 + 9223372036854775807LL, + "works for 64-bit numbers, wraparound high end"); + +template +inline constexpr bool TestEqual(T aX, T aY) { + return aX == aY; +} + +static void TestWrappingAdd8() { + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint8_t(0), uint8_t(128)), uint8_t(128)), + "zero plus anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint8_t(17), uint8_t(42)), uint8_t(59)), + "17 + 42 == 59"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint8_t(255), uint8_t(1)), uint8_t(0)), + "all bits plus one overflows to zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint8_t(128), uint8_t(127)), uint8_t(255)), + "high bit plus all lower bits is all bits"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint8_t(128), uint8_t(193)), uint8_t(65)), + "128 + 193 is 256 + 65"); + + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int8_t(0), int8_t(-128)), int8_t(-128)), + "zero plus anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int8_t(123), int8_t(8)), int8_t(-125)), + "overflow to negative"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int8_t(5), int8_t(-123)), int8_t(-118)), + "5 - 123 is -118"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int8_t(-85), int8_t(-73)), int8_t(98)), + "underflow to positive"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int8_t(-128), int8_t(127)), int8_t(-1)), + "high bit plus all lower bits is -1"); +} + +static void TestWrappingAdd16() { + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint16_t(0), uint16_t(32768)), uint16_t(32768)), + "zero plus anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint16_t(24389), uint16_t(2682)), uint16_t(27071)), + "24389 + 2682 == 27071"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint16_t(65535), uint16_t(1)), uint16_t(0)), + "all bits plus one overflows to zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint16_t(32768), uint16_t(32767)), uint16_t(65535)), + "high bit plus all lower bits is all bits"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint16_t(32768), uint16_t(47582)), uint16_t(14814)), + "32768 + 47582 is 65536 + 14814"); + + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int16_t(0), int16_t(-32768)), int16_t(-32768)), + "zero plus anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int16_t(32765), int16_t(8)), int16_t(-32763)), + "overflow to negative"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int16_t(5), int16_t(-28933)), int16_t(-28928)), + "5 - 28933 is -28928"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int16_t(-23892), int16_t(-12893)), int16_t(28751)), + "underflow to positive"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int16_t(-32768), int16_t(32767)), int16_t(-1)), + "high bit plus all lower bits is -1"); +} + +static void TestWrappingAdd32() { + MOZ_RELEASE_ASSERT(TestEqual(WrappingAdd(uint32_t(0), uint32_t(2147483648)), + uint32_t(2147483648)), + "zero plus anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint32_t(1398742328), uint32_t(714192829)), + uint32_t(2112935157)), + "1398742328 + 714192829 == 2112935157"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint32_t(4294967295), uint32_t(1)), uint32_t(0)), + "all bits plus one overflows to zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint32_t(2147483648), uint32_t(2147483647)), + uint32_t(4294967295)), + "high bit plus all lower bits is all bits"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint32_t(2147483648), uint32_t(3146492712)), + uint32_t(999009064)), + "2147483648 + 3146492712 is 4294967296 + 999009064"); + + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int32_t(0), int32_t(-2147483647 - 1)), + int32_t(-2147483647 - 1)), + "zero plus anything is anything"); + MOZ_RELEASE_ASSERT(TestEqual(WrappingAdd(int32_t(2147483645), int32_t(8)), + int32_t(-2147483643)), + "overflow to negative"); + MOZ_RELEASE_ASSERT(TestEqual(WrappingAdd(int32_t(257), int32_t(-23947248)), + int32_t(-23946991)), + "257 - 23947248 is -23946991"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int32_t(-2147483220), int32_t(-12893)), + int32_t(2147471183)), + "underflow to positive"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int32_t(-32768), int32_t(32767)), int32_t(-1)), + "high bit plus all lower bits is -1"); +} + +static void TestWrappingAdd64() { + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint64_t(0), uint64_t(9223372036854775808ULL)), + uint64_t(9223372036854775808ULL)), + "zero plus anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint64_t(70368744177664), uint64_t(3740873592)), + uint64_t(70372485051256)), + "70368744177664 + 3740873592 == 70372485051256"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(uint64_t(18446744073709551615ULL), uint64_t(1)), + uint64_t(0)), + "all bits plus one overflows to zero"); + MOZ_RELEASE_ASSERT(TestEqual(WrappingAdd(uint64_t(9223372036854775808ULL), + uint64_t(9223372036854775807ULL)), + uint64_t(18446744073709551615ULL)), + "high bit plus all lower bits is all bits"); + MOZ_RELEASE_ASSERT(TestEqual(WrappingAdd(uint64_t(14552598638644786479ULL), + uint64_t(3894174382537247221ULL)), + uint64_t(28947472482084)), + "9223372036854775808 + 3146492712 is 18446744073709551616 " + "+ 28947472482084"); + + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int64_t(0), int64_t(-9223372036854775807LL - 1)), + int64_t(-9223372036854775807LL - 1)), + "zero plus anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int64_t(9223372036854775802LL), int64_t(8)), + int64_t(-9223372036854775806LL)), + "overflow to negative"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingAdd(int64_t(37482739294298742LL), + int64_t(-437843573929483498LL)), + int64_t(-400360834635184756LL)), + "37482739294298742 - 437843573929483498 is -400360834635184756"); + MOZ_RELEASE_ASSERT(TestEqual(WrappingAdd(int64_t(-9127837934058953374LL), + int64_t(-4173572032144775807LL)), + int64_t(5145334107505822435L)), + "underflow to positive"); + MOZ_RELEASE_ASSERT(TestEqual(WrappingAdd(int64_t(-9223372036854775807LL - 1), + int64_t(9223372036854775807LL)), + int64_t(-1)), + "high bit plus all lower bits is -1"); +} + +static void TestWrappingAdd() { + TestWrappingAdd8(); + TestWrappingAdd16(); + TestWrappingAdd32(); + TestWrappingAdd64(); +} + +static void TestWrappingSubtract8() { + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint8_t(0), uint8_t(128)), uint8_t(128)), + "zero minus half is half"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint8_t(17), uint8_t(42)), uint8_t(231)), + "17 - 42 == -25 added to 256 is 231"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint8_t(0), uint8_t(1)), uint8_t(255)), + "zero underflows to all bits"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint8_t(128), uint8_t(127)), uint8_t(1)), + "128 - 127 == 1"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint8_t(128), uint8_t(193)), uint8_t(191)), + "128 - 193 is -65 so -65 + 256 == 191"); + + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int8_t(0), int8_t(-128)), int8_t(-128)), + "zero minus high bit wraps to high bit"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int8_t(-126), int8_t(4)), int8_t(126)), + "underflow to positive"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int8_t(5), int8_t(-123)), int8_t(-128)), + "overflow to negative"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int8_t(-85), int8_t(-73)), int8_t(-12)), + "negative minus smaller negative"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int8_t(-128), int8_t(127)), int8_t(1)), + "underflow to 1"); +} + +static void TestWrappingSubtract16() { + MOZ_RELEASE_ASSERT(TestEqual(WrappingSubtract(uint16_t(0), uint16_t(32768)), + uint16_t(32768)), + "zero minus half is half"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint16_t(24389), uint16_t(2682)), + uint16_t(21707)), + "24389 - 2682 == 21707"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint16_t(0), uint16_t(1)), uint16_t(65535)), + "zero underflows to all bits"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint16_t(32768), uint16_t(32767)), + uint16_t(1)), + "high bit minus all lower bits is one"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint16_t(32768), uint16_t(47582)), + uint16_t(50722)), + "32768 - 47582 + 65536 is 50722"); + + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int16_t(0), int16_t(-32768)), int16_t(-32768)), + "zero minus high bit wraps to high bit"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int16_t(-32766), int16_t(4)), int16_t(32766)), + "underflow to positive"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int16_t(5), int16_t(-28933)), int16_t(28938)), + "5 - -28933 is 28938"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int16_t(-23892), int16_t(-12893)), + int16_t(-10999)), + "negative minus smaller negative"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int16_t(-32768), int16_t(32767)), int16_t(1)), + "underflow to 1"); +} + +static void TestWrappingSubtract32() { + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint32_t(0), uint32_t(2147483648)), + uint32_t(2147483648)), + "zero minus half is half"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint32_t(1398742328), uint32_t(714192829)), + uint32_t(684549499)), + "1398742328 - 714192829 == 684549499"); + MOZ_RELEASE_ASSERT(TestEqual(WrappingSubtract(uint32_t(0), uint32_t(1)), + uint32_t(4294967295)), + "zero underflows to all bits"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint32_t(2147483648), uint32_t(2147483647)), + uint32_t(1)), + "high bit minus all lower bits is one"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint32_t(2147483648), uint32_t(3146492712)), + uint32_t(3295958232)), + "2147483648 - 3146492712 + 4294967296 is 3295958232"); + + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int32_t(0), int32_t(-2147483647 - 1)), + int32_t(-2147483647 - 1)), + "zero minus high bit wraps to high bit"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int32_t(-2147483646), int32_t(4)), + int32_t(2147483646)), + "underflow to positive"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int32_t(257), int32_t(-23947248)), + int32_t(23947505)), + "257 - -23947248 is 23947505"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int32_t(-2147483220), int32_t(-12893)), + int32_t(-2147470327)), + "negative minus smaller negative"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int32_t(-2147483647 - 1), int32_t(2147483647)), + int32_t(1)), + "underflow to 1"); +} + +static void TestWrappingSubtract64() { + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint64_t(0), uint64_t(9223372036854775808ULL)), + uint64_t(9223372036854775808ULL)), + "zero minus half is half"); + MOZ_RELEASE_ASSERT(TestEqual(WrappingSubtract(uint64_t(70368744177664), + uint64_t(3740873592)), + uint64_t(70365003304072)), + "70368744177664 - 3740873592 == 70365003304072"); + MOZ_RELEASE_ASSERT(TestEqual(WrappingSubtract(uint64_t(0), uint64_t(1)), + uint64_t(18446744073709551615ULL)), + "zero underflows to all bits"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint64_t(9223372036854775808ULL), + uint64_t(9223372036854775807ULL)), + uint64_t(1)), + "high bit minus all lower bits is one"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(uint64_t(14552598638644786479ULL), + uint64_t(3894174382537247221ULL)), + uint64_t(10658424256107539258ULL)), + "14552598638644786479 - 39763621533397112216 is 10658424256107539258L"); + + MOZ_RELEASE_ASSERT( + TestEqual( + WrappingSubtract(int64_t(0), int64_t(-9223372036854775807LL - 1)), + int64_t(-9223372036854775807LL - 1)), + "zero minus high bit wraps to high bit"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int64_t(-9223372036854775802LL), int64_t(8)), + int64_t(9223372036854775806LL)), + "overflow to negative"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int64_t(37482739294298742LL), + int64_t(-437843573929483498LL)), + int64_t(475326313223782240)), + "37482739294298742 - -437843573929483498 is 475326313223782240"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int64_t(-9127837934058953374LL), + int64_t(-4173572032144775807LL)), + int64_t(-4954265901914177567LL)), + "negative minus smaller negative"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingSubtract(int64_t(-9223372036854775807LL - 1), + int64_t(9223372036854775807LL)), + int64_t(1)), + "underflow to 1"); +} + +static void TestWrappingSubtract() { + TestWrappingSubtract8(); + TestWrappingSubtract16(); + TestWrappingSubtract32(); + TestWrappingSubtract64(); +} + +static void TestWrappingMultiply8() { + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint8_t(0), uint8_t(128)), uint8_t(0)), + "zero times anything is zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint8_t(128), uint8_t(1)), uint8_t(128)), + "1 times anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint8_t(2), uint8_t(128)), uint8_t(0)), + "2 times high bit overflows, produces zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint8_t(8), uint8_t(16)), uint8_t(128)), + "multiply that populates the high bit produces that value"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint8_t(127), uint8_t(127)), uint8_t(1)), + "multiplying signed maxvals overflows all the way to 1"); + + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int8_t(0), int8_t(-128)), int8_t(0)), + "zero times anything is zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int8_t(-128), int8_t(1)), int8_t(-128)), + "1 times anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int8_t(2), int8_t(-128)), int8_t(0)), + "2 times min overflows, produces zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int8_t(16), int8_t(24)), int8_t(-128)), + "multiply that populates the sign bit produces minval"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int8_t(8), int8_t(16)), int8_t(-128)), + "multiply that populates the sign bit produces minval"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int8_t(127), int8_t(127)), int8_t(1)), + "multiplying maxvals overflows all the way to 1"); +} + +static void TestWrappingMultiply16() { + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint16_t(0), uint16_t(32768)), uint16_t(0)), + "zero times anything is zero"); + MOZ_RELEASE_ASSERT(TestEqual(WrappingMultiply(uint16_t(32768), uint16_t(1)), + uint16_t(32768)), + "1 times anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint16_t(2), uint16_t(32768)), uint16_t(0)), + "2 times high bit overflows, produces zero"); + MOZ_RELEASE_ASSERT(TestEqual(WrappingMultiply(uint16_t(3), uint16_t(32768)), + uint16_t(-32768)), + "3 * 32768 - 65536 is 32768"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint16_t(64), uint16_t(512)), uint16_t(32768)), + "multiply that populates the high bit produces that value"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint16_t(32767), uint16_t(32767)), + uint16_t(1)), + "multiplying signed maxvals overflows all the way to 1"); + + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int16_t(0), int16_t(-32768)), int16_t(0)), + "zero times anything is zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int16_t(-32768), int16_t(1)), int16_t(-32768)), + "1 times anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int16_t(-456), int16_t(123)), int16_t(9448)), + "multiply opposite signs, then add 2**16 for the result"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int16_t(2), int16_t(-32768)), int16_t(0)), + "2 times min overflows, produces zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int16_t(64), int16_t(512)), int16_t(-32768)), + "multiply that populates the sign bit produces minval"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int16_t(32767), int16_t(32767)), int16_t(1)), + "multiplying maxvals overflows all the way to 1"); +} + +static void TestWrappingMultiply32() { + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint32_t(0), uint32_t(2147483648)), + uint32_t(0)), + "zero times anything is zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint32_t(42), uint32_t(17)), uint32_t(714)), + "42 * 17 is 714 without wraparound"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint32_t(2147483648), uint32_t(1)), + uint32_t(2147483648)), + "1 times anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint32_t(2), uint32_t(2147483648)), + uint32_t(0)), + "2 times high bit overflows, produces zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint32_t(8192), uint32_t(262144)), + uint32_t(2147483648)), + "multiply that populates the high bit produces that value"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint32_t(2147483647), uint32_t(2147483647)), + uint32_t(1)), + "multiplying signed maxvals overflows all the way to 1"); + + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int32_t(0), int32_t(-2147483647 - 1)), + int32_t(0)), + "zero times anything is zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int32_t(-2147483647 - 1), int32_t(1)), + int32_t(-2147483647 - 1)), + "1 times anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int32_t(2), int32_t(-2147483647 - 1)), + int32_t(0)), + "2 times min overflows, produces zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int32_t(-7), int32_t(-9)), int32_t(63)), + "-7 * -9 is 63, no wraparound needed"); + MOZ_RELEASE_ASSERT(TestEqual(WrappingMultiply(int32_t(8192), int32_t(262144)), + int32_t(-2147483647 - 1)), + "multiply that populates the sign bit produces minval"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int32_t(2147483647), int32_t(2147483647)), + int32_t(1)), + "multiplying maxvals overflows all the way to 1"); +} + +static void TestWrappingMultiply64() { + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint64_t(0), uint64_t(9223372036854775808ULL)), + uint64_t(0)), + "zero times anything is zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint64_t(9223372036854775808ULL), uint64_t(1)), + uint64_t(9223372036854775808ULL)), + "1 times anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint64_t(2), uint64_t(9223372036854775808ULL)), + uint64_t(0)), + "2 times high bit overflows, produces zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(uint64_t(131072), uint64_t(70368744177664)), + uint64_t(9223372036854775808ULL)), + "multiply that populates the high bit produces that value"); + MOZ_RELEASE_ASSERT(TestEqual(WrappingMultiply(uint64_t(9223372036854775807), + uint64_t(9223372036854775807)), + uint64_t(1)), + "multiplying signed maxvals overflows all the way to 1"); + + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int64_t(0), int64_t(-9223372036854775807 - 1)), + int64_t(0)), + "zero times anything is zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int64_t(-9223372036854775807 - 1), int64_t(1)), + int64_t(-9223372036854775807 - 1)), + "1 times anything is anything"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int64_t(2), int64_t(-9223372036854775807 - 1)), + int64_t(0)), + "2 times min overflows, produces zero"); + MOZ_RELEASE_ASSERT( + TestEqual(WrappingMultiply(int64_t(131072), int64_t(70368744177664)), + int64_t(-9223372036854775807 - 1)), + "multiply that populates the sign bit produces minval"); + MOZ_RELEASE_ASSERT(TestEqual(WrappingMultiply(int64_t(9223372036854775807), + int64_t(9223372036854775807)), + int64_t(1)), + "multiplying maxvals overflows all the way to 1"); +} + +static void TestWrappingMultiply() { + TestWrappingMultiply8(); + TestWrappingMultiply16(); + TestWrappingMultiply32(); + TestWrappingMultiply64(); +} + +int main() { + TestWrappingAdd(); + TestWrappingSubtract(); + TestWrappingMultiply(); + return 0; +} -- cgit v1.2.3