diff options
Diffstat (limited to 'libc/test/src/stdio/sprintf_test.cpp')
| -rw-r--r-- | libc/test/src/stdio/sprintf_test.cpp | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/libc/test/src/stdio/sprintf_test.cpp b/libc/test/src/stdio/sprintf_test.cpp index e8303ff3416b..f6af6ad3e364 100644 --- a/libc/test/src/stdio/sprintf_test.cpp +++ b/libc/test/src/stdio/sprintf_test.cpp @@ -1861,6 +1861,113 @@ TEST(LlvmLibcSPrintfTest, FloatDecimalLongDoubleConv) { "179817332113"); #endif #endif // LIBC_TYPES_LONG_DOUBLE_IS_X86_FLOAT80 + +#if defined(LIBC_TYPES_LONG_DOUBLE_IS_FLOAT128) + // Some exceptionally difficult cases for 39-digit precision. (That's the + // number of digits supported by the float320 algorithm, and should still be + // correct under other algorithms. So these are still enabled even under + // LIBC_COPT_FLOAT_TO_STR_REDUCED_PRECISION.) + // + // These were found by number-theoretic search to be the worst cases in terms + // of being extremely close to the rounding boundary between two possible + // decimal outputs. For example, the first of these cases has a true value + // beginning with + // + // 2.245786964418815522831613614422112838795000000000000000000 + // 0000000000000000010767969... + // + // so you need to compute a _long_ way past the 39th digit to find out + // whether to round the ...8795 up to 880 or not! + // + // The first half of these cases all rounded up; the second half all rounded + // down. You can see that in both sections the final decimal digit is + // sometimes odd and sometimes even, ruling out the possibility that we're + // getting these right by mistakenly assuming them to be _exactly_ on the + // boundary. + + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.bde5716bba8d70255b4be10e0a0ap-3388L); + ASSERT_STREQ_LEN(written, buff, + "2.24578696441881552283161361442211283880e-1020"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.64b78defc8712684490980d80808p-3391L); + ASSERT_STREQ_LEN(written, buff, + "2.24578696441881552283161361442211283880e-1021"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.c0eed9d1ea4b6f215accb15cb42cp-4714L); + ASSERT_STREQ_LEN(written, buff, + "1.54362575487963943466308346767014523161e-1419"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.a393eaafc3dbabfcd30442cef525p-12600L); + ASSERT_STREQ_LEN(written, buff, + "1.72435694193924008931441874634575361189e-3793"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.b7a5248baf85133c9b7bf3241f75p+11050L); + ASSERT_STREQ_LEN(written, buff, + "4.13346579244549095104252956440178208514e+3326"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.81bf6d977f99ff7bd9debdd52815p+1359L); + ASSERT_STREQ_LEN(written, buff, + "1.89595297593127274811683259716608232064e+409"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.fcb9cfd65f068b758d30ba19a494p-4451L); + ASSERT_STREQ_LEN(written, buff, + "2.59258570015527007681686041122929728653e-1340"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.7d8b5be0c744e89829e48b933b6fp-4448L); + ASSERT_STREQ_LEN(written, buff, + "1.55555142009316204609011624673757837192e-1339"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.dbb1f01aef7b93c37ca00217888cp-12205L); + ASSERT_STREQ_LEN(written, buff, + "1.57758077908296078543773740016012372216e-3674"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.fb037d72fdf1a8aa8bdfc2586fe3p+2580L); + ASSERT_STREQ_LEN(written, buff, + "8.99846610004600287527755301065037553046e+776"); + + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.9af8fe5febf751a795292e30335dp+2052L); + ASSERT_STREQ_LEN(written, buff, + "8.30087814106622071390265113980150545241e+617"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.48c731e6565f748610edbe8cf5e4p+2049L); + ASSERT_STREQ_LEN(written, buff, + "8.30087814106622071390265113980150545241e+616"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.8e78bc76e98998b7bbf6c8f80f2ap-5671L); + ASSERT_STREQ_LEN(written, buff, + "1.12473970318904704063044350553302771341e-1707"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.59a832c16a7797aec70196ddf9dbp-16181L); + ASSERT_STREQ_LEN(written, buff, + "1.45896738321434823250358135932839533040e-4871"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.14868f0121f946256c01457e617cp-16184L); + ASSERT_STREQ_LEN(written, buff, + "1.45896738321434823250358135932839533040e-4872"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.0ca8c4b525b1128506cdc668df43p+11017L); + ASSERT_STREQ_LEN(written, buff, + "2.94051951004764266903705588743096762647e+3316"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.fcd40bb49b18aa19d66a3c5572dep+5547L); + ASSERT_STREQ_LEN(written, buff, + "1.29335350323078956384272678475060580129e+1670"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.0e5e51510a653e744d6b84efed86p-13613L); + ASSERT_STREQ_LEN(written, buff, + "1.26585813611514592337442314391432904094e-4098"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.ff41f8aa97e676e95b1a6a7751fap+16366L); + ASSERT_STREQ_LEN(written, buff, + "9.06377119787295161934827646572467920486e+4926"); + written = LIBC_NAMESPACE::sprintf(buff, "%#.39Lg", + 0x1.4770bf66ccafd7d80ac9bb3dded7p-1843L); + ASSERT_STREQ_LEN(written, buff, + "2.03521509642091239545213340619368190283e-555"); + +#endif // LIBC_TYPES_LONG_DOUBLE_IS_FLOAT128 } TEST(LlvmLibcSPrintfTest, FloatExponentConv) { |