221 changes: 221 additions & 0 deletions libc/test/src/stdlib/strtold_test.cpp
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//===-- Unittests for strtold ---------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "src/__support/FPUtil/FPBits.h"
#include "src/stdlib/strtold.h"

#include "utils/UnitTest/Test.h"

#include <errno.h>
#include <limits.h>
#include <stddef.h>

class LlvmLibcStrToLDTest : public __llvm_libc::testing::Test {
public:
void runTest(const char *inputString, const ptrdiff_t expectedStrLen,
const uint64_t expectedRawData64,
const __uint128_t expectedRawData80,
const __uint128_t expectedRawData128,
const int expectedErrno64 = 0, const int expectedErrno80 = 0,
const int expectedErrno128 = 0) {
// expectedRawData64 is the expected long double result as a uint64_t,
// organized according to the IEEE754 double precision format:
//
// +-- 1 Sign Bit +-- 52 Mantissa bits
// | |
// | +-------------------------+------------------------+
// | | |
// SEEEEEEEEEEEMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
// | |
// +----+----+
// |
// +-- 11 Exponent Bits

// expectedRawData80 is the expected long double result as a __uint128_t,
// organized according to the x86 extended precision format:
//
// +-- 1 Sign Bit
// |
// | +-- 1 Integer part bit (1 unless this is a subnormal)
// | |
// SEEEEEEEEEEEEEEEIMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM...M
// | | | |
// +------+------+ +---------------------------+--------------------------+
// | |
// +-- 15 Exponent Bits +-- 63 Mantissa bits

// expectedRawData64 is the expected long double result as a __uint128_t,
// organized according to IEEE754 quadruple precision format:
//
// +-- 1 Sign Bit +-- 112 Mantissa bits
// | |
// | +----------------------------+--------------------------+
// | | |
// SEEEEEEEEEEEEEEEMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM...M
// | |
// +------+------+
// |
// +-- 15 Exponent Bits
char *strEnd = nullptr;

#if defined(LONG_DOUBLE_IS_DOUBLE)
__llvm_libc::fputil::FPBits<long double> expectedFP =
__llvm_libc::fputil::FPBits<long double>(expectedRawData64);
const int expectedErrno = expectedErrno64;
#elif defined(SPECIAL_X86_LONG_DOUBLE)
__llvm_libc::fputil::FPBits<long double> expectedFP =
__llvm_libc::fputil::FPBits<long double>(expectedRawData80);
const int expectedErrno = expectedErrno80;
#else
__llvm_libc::fputil::FPBits<long double> expectedFP =
__llvm_libc::fputil::FPBits<long double>(expectedRawData128);
const int expectedErrno = expectedErrno128;
#endif

errno = 0;
long double result = __llvm_libc::strtold(inputString, &strEnd);

__llvm_libc::fputil::FPBits<long double> actualFP =
__llvm_libc::fputil::FPBits<long double>();
actualFP = __llvm_libc::fputil::FPBits<long double>(result);

EXPECT_EQ(strEnd - inputString, expectedStrLen);

EXPECT_EQ(actualFP.bits, expectedFP.bits);
EXPECT_EQ(actualFP.get_sign(), expectedFP.get_sign());
EXPECT_EQ(actualFP.get_exponent(), expectedFP.get_exponent());
EXPECT_EQ(actualFP.get_mantissa(), expectedFP.get_mantissa());
EXPECT_EQ(errno, expectedErrno);
}
};

TEST_F(LlvmLibcStrToLDTest, SimpleTest) {
runTest("123", 3, uint64_t(0x405ec00000000000),
__uint128_t(0x4005f60000) << 40,
__uint128_t(0x4005ec0000000000) << 64);

// This should fail on Eisel-Lemire, forcing a fallback to simple decimal
// conversion.
runTest("12345678901234549760", 20, uint64_t(0x43e56a95319d63d8),
(__uint128_t(0x403eab54a9) << 40) + __uint128_t(0x8ceb1ec400),
(__uint128_t(0x403e56a95319d63d) << 64) +
__uint128_t(0x8800000000000000));

// Found while looking for difficult test cases here:
// https://github.com/nigeltao/parse-number-fxx-test-data/blob/main/more-test-cases/golang-org-issue-36657.txt
runTest("1090544144181609348835077142190", 31, uint64_t(0x462b8779f2474dfb),
(__uint128_t(0x4062dc3bcf) << 40) + __uint128_t(0x923a6fd402),
(__uint128_t(0x4062b8779f2474df) << 64) +
__uint128_t(0xa804bfd8c6d5c000));

runTest("0x123", 5, uint64_t(0x4072300000000000),
(__uint128_t(0x4007918000) << 40),
(__uint128_t(0x4007230000000000) << 64));
}

// These are tests that have caused problems for doubles in the past.
TEST_F(LlvmLibcStrToLDTest, Float64SpecificFailures) {
runTest("3E70000000000000", 16, uint64_t(0x7FF0000000000000),
(__uint128_t(0x7fff800000) << 40),
(__uint128_t(0x7fff000000000000) << 64), ERANGE, ERANGE, ERANGE);
runTest("358416272e-33", 13, uint64_t(0x3adbbb2a68c9d0b9),
(__uint128_t(0x3fadddd953) << 40) + __uint128_t(0x464e85c400),
(__uint128_t(0x3fadbbb2a68c9d0b) << 64) +
__uint128_t(0x8800e7969e1c5fc8));
runTest(
"2.16656806400000023841857910156251e9", 36, uint64_t(0x41e0246690000001),
(__uint128_t(0x401e812334) << 40) + __uint128_t(0x8000000400),
(__uint128_t(0x401e024669000000) << 64) + __uint128_t(0x800000000000018));
runTest("27949676547093071875", 20, uint64_t(0x43f83e132bc608c9),
(__uint128_t(0x403fc1f099) << 40) + __uint128_t(0x5e30464402),
(__uint128_t(0x403f83e132bc608c) << 64) +
__uint128_t(0x8803000000000000));
}

TEST_F(LlvmLibcStrToLDTest, MaxSizeNumbers) {
runTest("1.1897314953572317650e4932", 26, uint64_t(0x7FF0000000000000),
(__uint128_t(0x7ffeffffff) << 40) + __uint128_t(0xffffffffff),
(__uint128_t(0x7ffeffffffffffff) << 64) +
__uint128_t(0xfffd57322e3f8675),
ERANGE, 0, 0);
runTest("1.18973149535723176508e4932", 27, uint64_t(0x7FF0000000000000),
(__uint128_t(0x7fff800000) << 40),
(__uint128_t(0x7ffeffffffffffff) << 64) +
__uint128_t(0xffffd2478338036c),
ERANGE, ERANGE, 0);
}

// These tests check subnormal behavior for 80 bit and 128 bit floats. They will
// be too small for 64 bit floats.
TEST_F(LlvmLibcStrToLDTest, SubnormalTests) {
runTest("1e-4950", 7, uint64_t(0), (__uint128_t(0x00000000000000000003)),
(__uint128_t(0x000000000000000000057c9647e1a018)), ERANGE, ERANGE,
ERANGE);
runTest("1.89e-4951", 10, uint64_t(0), (__uint128_t(0x00000000000000000001)),
(__uint128_t(0x0000000000000000000109778a006738)), ERANGE, ERANGE,
ERANGE);
runTest("4e-4966", 7, uint64_t(0), (__uint128_t(0)),
(__uint128_t(0x00000000000000000000000000000001)), ERANGE, ERANGE,
ERANGE);
}

TEST_F(LlvmLibcStrToLDTest, SmallNormalTests) {
runTest("3.37e-4932", 10, uint64_t(0),
(__uint128_t(0x1804cf7) << 40) + __uint128_t(0x908850712),
(__uint128_t(0x10099ee12110a) << 64) + __uint128_t(0xe24b75c0f50dc0c),
ERANGE, 0, 0);
}

TEST_F(LlvmLibcStrToLDTest, ComplexHexadecimalTests) {
runTest("0x1p16383", 9, 0x7ff0000000000000, (__uint128_t(0x7ffe800000) << 40),
(__uint128_t(0x7ffe000000000000) << 64));
runTest("0x123456789abcdef", 17, 0x43723456789abcdf,
(__uint128_t(0x403791a2b3) << 40) + __uint128_t(0xc4d5e6f780),
(__uint128_t(0x403723456789abcd) << 64) +
__uint128_t(0xef00000000000000));
runTest("0x123456789abcdef0123456789ABCDEF", 33, 0x7ff0000000000000,
(__uint128_t(0x407791a2b3) << 40) + __uint128_t(0xc4d5e6f781),
(__uint128_t(0x407723456789abcd) << 64) +
__uint128_t(0xef0123456789abce));
}

TEST_F(LlvmLibcStrToLDTest, InfTests) {
runTest("INF", 3, 0x7ff0000000000000, (__uint128_t(0x7fff800000) << 40),
(__uint128_t(0x7fff000000000000) << 64));
runTest("INFinity", 8, 0x7ff0000000000000, (__uint128_t(0x7fff800000) << 40),
(__uint128_t(0x7fff000000000000) << 64));
runTest("-inf", 4, 0xfff0000000000000, (__uint128_t(0xffff800000) << 40),
(__uint128_t(0xffff000000000000) << 64));
}

TEST_F(LlvmLibcStrToLDTest, NaNTests) {
runTest("NaN", 3, 0x7ff8000000000000, (__uint128_t(0x7fffc00000) << 40),
(__uint128_t(0x7fff800000000000) << 64));
runTest("-nAn", 4, 0xfff8000000000000, (__uint128_t(0xffffc00000) << 40),
(__uint128_t(0xffff800000000000) << 64));
runTest("NaN()", 5, 0x7ff8000000000000, (__uint128_t(0x7fffc00000) << 40),
(__uint128_t(0x7fff800000000000) << 64));
runTest("NaN(1234)", 9, 0x7ff80000000004d2,
(__uint128_t(0x7fffc00000) << 40) + __uint128_t(0x4d2),
(__uint128_t(0x7fff800000000000) << 64) + __uint128_t(0x4d2));
runTest("NaN(0xffffffffffff)", 19, 0x7ff8ffffffffffff,
(__uint128_t(0x7fffc000ff) << 40) + __uint128_t(0xffffffffff),
(__uint128_t(0x7fff800000000000) << 64) +
__uint128_t(0xffffffffffff));
runTest("NaN(0xfffffffffffff)", 20, 0x7fffffffffffffff,
(__uint128_t(0x7fffc00fff) << 40) + __uint128_t(0xffffffffff),
(__uint128_t(0x7fff800000000000) << 64) +
__uint128_t(0xfffffffffffff));
runTest("NaN(0xffffffffffffffff)", 23, 0x7fffffffffffffff,
(__uint128_t(0x7fffffffff) << 40) + __uint128_t(0xffffffffff),
(__uint128_t(0x7fff800000000000) << 64) +
__uint128_t(0xffffffffffffffff));
runTest("NaN( 1234)", 3, 0x7ff8000000000000,
(__uint128_t(0x7fffc00000) << 40),
(__uint128_t(0x7fff800000000000) << 64));
}