1//===-- Unittests for strtof ----------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "src/__support/FPUtil/FPBits.h"
10#include "src/stdlib/strtof.h"
11
12#include "test/UnitTest/ErrnoCheckingTest.h"
13#include "test/UnitTest/FPMatcher.h"
14#include "test/UnitTest/RoundingModeUtils.h"
15#include "test/UnitTest/Test.h"
16
17#include <stddef.h>
18
19using LIBC_NAMESPACE::fputil::testing::ForceRoundingModeTest;
20using LIBC_NAMESPACE::fputil::testing::RoundingMode;
21
22class LlvmLibcStrToFTest : public LIBC_NAMESPACE::testing::ErrnoCheckingTest,
23 ForceRoundingModeTest<RoundingMode::Nearest> {
24public:
25 void run_test(const char *inputString, const ptrdiff_t expectedStrLen,
26 const uint32_t expectedRawData, const int expectedErrno = 0) {
27 // expectedRawData is the expected float result as a uint32_t, organized
28 // according to IEEE754:
29 //
30 // +-- 1 Sign Bit +-- 23 Mantissa bits
31 // | |
32 // | +----------+----------+
33 // | | |
34 // SEEEEEEEEMMMMMMMMMMMMMMMMMMMMMMM
35 // | |
36 // +--+---+
37 // |
38 // +-- 8 Exponent Bits
39 //
40 // This is so that the result can be compared in parts.
41 char *str_end = nullptr;
42
43 LIBC_NAMESPACE::fputil::FPBits<float> expected_fp =
44 LIBC_NAMESPACE::fputil::FPBits<float>(expectedRawData);
45
46 float result = LIBC_NAMESPACE::strtof(inputString, &str_end);
47
48 EXPECT_EQ(str_end - inputString, expectedStrLen);
49 EXPECT_FP_EQ(result, expected_fp.get_val());
50 ASSERT_ERRNO_EQ(expectedErrno);
51 }
52};
53
54// This is the set of tests that I have working (verified correct when compared
55// to system libc). This is here so I don't break more things when I try to fix
56// them.
57
58TEST_F(LlvmLibcStrToFTest, BasicDecimalTests) {
59 run_test("1", 1, 0x3f800000);
60 run_test("123", 3, 0x42f60000);
61 run_test("1234567890", 10, 0x4e932c06u);
62 run_test("123456789012345678901", 21, 0x60d629d4);
63 run_test("0.1", 3, 0x3dcccccdu);
64 run_test(".1", 2, 0x3dcccccdu);
65 run_test("-0.123456789", 12, 0xbdfcd6eau);
66 run_test("0.11111111111111111111", 22, 0x3de38e39u);
67 run_test("0.0000000000000000000000001", 27, 0x15f79688u);
68}
69
70TEST_F(LlvmLibcStrToFTest, DecimalOutOfRangeTests) {
71 run_test("555E36", 6, 0x7f800000, ERANGE);
72 run_test("1e-10000", 8, 0x0, ERANGE);
73}
74
75TEST_F(LlvmLibcStrToFTest, DecimalsWithRoundingProblems) {
76 run_test("20040229", 8, 0x4b98e512);
77 run_test("20040401", 8, 0x4b98e568);
78 run_test("9E9", 3, 0x50061c46);
79}
80
81TEST_F(LlvmLibcStrToFTest, DecimalSubnormals) {
82 run_test("1.4012984643248170709237295832899161312802619418765e-45", 55, 0x1,
83 ERANGE);
84}
85
86TEST_F(LlvmLibcStrToFTest, DecimalWithLongExponent) {
87 run_test("1e2147483648", 12, 0x7f800000, ERANGE);
88 run_test("1e2147483646", 12, 0x7f800000, ERANGE);
89 run_test("100e2147483646", 14, 0x7f800000, ERANGE);
90 run_test("1e-2147483647", 13, 0x0, ERANGE);
91 run_test("1e-2147483649", 13, 0x0, ERANGE);
92}
93
94TEST_F(LlvmLibcStrToFTest, BasicHexadecimalTests) {
95 run_test("0x1", 3, 0x3f800000);
96 run_test("0x10", 4, 0x41800000);
97 run_test("0x11", 4, 0x41880000);
98 run_test("0x0.1234", 8, 0x3d91a000);
99}
100
101TEST_F(LlvmLibcStrToFTest, HexadecimalSubnormalTests) {
102 run_test("0x0.0000000000000000000000000000000002", 38, 0x4000, ERANGE);
103
104 // This is the largest subnormal number as represented in hex
105 run_test("0x0.00000000000000000000000000000003fffff8", 42, 0x7fffff, ERANGE);
106}
107
108TEST_F(LlvmLibcStrToFTest, HexadecimalSubnormalRoundingTests) {
109 // This is the largest subnormal number that gets rounded down to 0 (as a
110 // float)
111 run_test("0x0.00000000000000000000000000000000000004", 42, 0x0, ERANGE);
112
113 // This is slightly larger, and thus rounded up
114 run_test("0x0.000000000000000000000000000000000000041", 43, 0x00000001,
115 ERANGE);
116
117 // These check that we're rounding to even properly
118 run_test("0x0.0000000000000000000000000000000000000b", 42, 0x00000001,
119 ERANGE);
120 run_test("0x0.0000000000000000000000000000000000000c", 42, 0x00000002,
121 ERANGE);
122
123 // These check that we're rounding to even properly even when the input bits
124 // are longer than the bit fields can contain.
125 run_test("0x1.000000000000000000000p-150", 30, 0x00000000, ERANGE);
126 run_test("0x1.000010000000000001000p-150", 30, 0x00000001, ERANGE);
127 run_test("0x1.000100000000000001000p-134", 30, 0x00008001, ERANGE);
128 run_test("0x1.FFFFFC000000000001000p-127", 30, 0x007FFFFF, ERANGE);
129 run_test("0x1.FFFFFE000000000000000p-127", 30, 0x00800000);
130}
131
132TEST_F(LlvmLibcStrToFTest, HexadecimalNormalRoundingTests) {
133 // This also checks the round to even behavior by checking three adjacent
134 // numbers.
135 // This gets rounded down to even
136 run_test("0x123456500", 11, 0x4f91a2b2);
137 // This doesn't get rounded at all
138 run_test("0x123456600", 11, 0x4f91a2b3);
139 // This gets rounded up to even
140 run_test("0x123456700", 11, 0x4f91a2b4);
141 // Correct rounding for long input
142 run_test("0x1.000001000000000000000", 25, 0x3f800000);
143 run_test("0x1.000001000000000000100", 25, 0x3f800001);
144}
145
146TEST_F(LlvmLibcStrToFTest, HexadecimalsWithRoundingProblems) {
147 run_test("0xFFFFFFFF", 10, 0x4f800000);
148}
149
150TEST_F(LlvmLibcStrToFTest, HexadecimalOutOfRangeTests) {
151 run_test("0x123456789123456789123456789123456789", 38, 0x7f800000, ERANGE);
152 run_test("-0x123456789123456789123456789123456789", 39, 0xff800000, ERANGE);
153 run_test("0x0.00000000000000000000000000000000000001", 42, 0x0, ERANGE);
154}
155
156TEST_F(LlvmLibcStrToFTest, InfTests) {
157 run_test("INF", 3, 0x7f800000);
158 run_test("INFinity", 8, 0x7f800000);
159 run_test("infnity", 3, 0x7f800000);
160 run_test("infinit", 3, 0x7f800000);
161 run_test("infinfinit", 3, 0x7f800000);
162 run_test("innf", 0, 0x0);
163 run_test("-inf", 4, 0xff800000);
164 run_test("-iNfInItY", 9, 0xff800000);
165}
166
167TEST_F(LlvmLibcStrToFTest, SimpleNaNTests) {
168 run_test("NaN", 3, 0x7fc00000);
169 run_test("-nAn", 4, 0xffc00000);
170}
171
172// These NaNs are of the form `NaN(n-character-sequence)` where the
173// n-character-sequence is 0 or more letters or numbers. If there is anything
174// other than a letter or a number, then the valid number is just `NaN`. If
175// the sequence is valid, then the interpretation of them is implementation
176// defined, in this case it's passed to strtoll with an automatic base, and
177// the result is put into the mantissa if it takes up the whole width of the
178// parentheses.
179TEST_F(LlvmLibcStrToFTest, NaNWithParenthesesEmptyTest) {
180 run_test("NaN()", 5, 0x7fc00000);
181}
182
183TEST_F(LlvmLibcStrToFTest, NaNWithParenthesesValidNumberTests) {
184 run_test("NaN(1234)", 9, 0x7fc004d2);
185 run_test("NaN(0x1234)", 11, 0x7fc01234);
186 run_test("NaN(01234)", 10, 0x7fc0029c);
187}
188
189TEST_F(LlvmLibcStrToFTest, NaNWithParenthesesInvalidSequenceTests) {
190 run_test("NaN( 1234)", 3, 0x7fc00000);
191 run_test("NaN(-1234)", 3, 0x7fc00000);
192 run_test("NaN(asd&f)", 3, 0x7fc00000);
193 run_test("NaN(123 )", 3, 0x7fc00000);
194 run_test("NaN(123+asdf)", 3, 0x7fc00000);
195 run_test("NaN(123", 3, 0x7fc00000);
196}
197
198TEST_F(LlvmLibcStrToFTest, NaNWithParenthesesValidSequenceInvalidNumberTests) {
199 run_test("NaN(1a)", 7, 0x7fc00000);
200 run_test("NaN(asdf)", 9, 0x7fc00000);
201 run_test("NaN(1A1)", 8, 0x7fc00000);
202 run_test("NaN(underscores_are_ok)", 23, 0x7fc00000);
203 run_test(
204 "NaN(1234567890qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM_)",
205 68, 0x7fc00000);
206}
207

source code of libc/test/src/stdlib/strtof_test.cpp