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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /vendor/serde_json/tests/lexical/rounding.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/serde_json/tests/lexical/rounding.rs')
-rw-r--r-- | vendor/serde_json/tests/lexical/rounding.rs | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/vendor/serde_json/tests/lexical/rounding.rs b/vendor/serde_json/tests/lexical/rounding.rs new file mode 100644 index 000000000..7ea17716c --- /dev/null +++ b/vendor/serde_json/tests/lexical/rounding.rs @@ -0,0 +1,316 @@ +// Adapted from https://github.com/Alexhuszagh/rust-lexical. + +use crate::lexical::float::ExtendedFloat; +use crate::lexical::num::Float; +use crate::lexical::rounding::*; + +// MASKS + +#[test] +fn lower_n_mask_test() { + assert_eq!(lower_n_mask(0u64), 0b0); + assert_eq!(lower_n_mask(1u64), 0b1); + assert_eq!(lower_n_mask(2u64), 0b11); + assert_eq!(lower_n_mask(10u64), 0b1111111111); + assert_eq!(lower_n_mask(32u64), 0b11111111111111111111111111111111); +} + +#[test] +fn lower_n_halfway_test() { + assert_eq!(lower_n_halfway(0u64), 0b0); + assert_eq!(lower_n_halfway(1u64), 0b1); + assert_eq!(lower_n_halfway(2u64), 0b10); + assert_eq!(lower_n_halfway(10u64), 0b1000000000); + assert_eq!(lower_n_halfway(32u64), 0b10000000000000000000000000000000); +} + +#[test] +fn nth_bit_test() { + assert_eq!(nth_bit(0u64), 0b1); + assert_eq!(nth_bit(1u64), 0b10); + assert_eq!(nth_bit(2u64), 0b100); + assert_eq!(nth_bit(10u64), 0b10000000000); + assert_eq!(nth_bit(31u64), 0b10000000000000000000000000000000); +} + +#[test] +fn internal_n_mask_test() { + assert_eq!(internal_n_mask(1u64, 0u64), 0b0); + assert_eq!(internal_n_mask(1u64, 1u64), 0b1); + assert_eq!(internal_n_mask(2u64, 1u64), 0b10); + assert_eq!(internal_n_mask(4u64, 2u64), 0b1100); + assert_eq!(internal_n_mask(10u64, 2u64), 0b1100000000); + assert_eq!(internal_n_mask(10u64, 4u64), 0b1111000000); + assert_eq!( + internal_n_mask(32u64, 4u64), + 0b11110000000000000000000000000000 + ); +} + +// NEAREST ROUNDING + +#[test] +fn round_nearest_test() { + // Check exactly halfway (b'1100000') + let mut fp = ExtendedFloat { mant: 0x60, exp: 0 }; + let (above, halfway) = round_nearest(&mut fp, 6); + assert!(!above); + assert!(halfway); + assert_eq!(fp.mant, 1); + + // Check above halfway (b'1100001') + let mut fp = ExtendedFloat { mant: 0x61, exp: 0 }; + let (above, halfway) = round_nearest(&mut fp, 6); + assert!(above); + assert!(!halfway); + assert_eq!(fp.mant, 1); + + // Check below halfway (b'1011111') + let mut fp = ExtendedFloat { mant: 0x5F, exp: 0 }; + let (above, halfway) = round_nearest(&mut fp, 6); + assert!(!above); + assert!(!halfway); + assert_eq!(fp.mant, 1); +} + +// DIRECTED ROUNDING + +#[test] +fn round_downward_test() { + // b0000000 + let mut fp = ExtendedFloat { mant: 0x00, exp: 0 }; + round_downward(&mut fp, 6); + assert_eq!(fp.mant, 0); + + // b1000000 + let mut fp = ExtendedFloat { mant: 0x40, exp: 0 }; + round_downward(&mut fp, 6); + assert_eq!(fp.mant, 1); + + // b1100000 + let mut fp = ExtendedFloat { mant: 0x60, exp: 0 }; + round_downward(&mut fp, 6); + assert_eq!(fp.mant, 1); + + // b1110000 + let mut fp = ExtendedFloat { mant: 0x70, exp: 0 }; + round_downward(&mut fp, 6); + assert_eq!(fp.mant, 1); +} + +#[test] +fn round_nearest_tie_even_test() { + // Check round-up, halfway + let mut fp = ExtendedFloat { mant: 0x60, exp: 0 }; + round_nearest_tie_even(&mut fp, 6); + assert_eq!(fp.mant, 2); + + // Check round-down, halfway + let mut fp = ExtendedFloat { mant: 0x20, exp: 0 }; + round_nearest_tie_even(&mut fp, 6); + assert_eq!(fp.mant, 0); + + // Check round-up, above halfway + let mut fp = ExtendedFloat { mant: 0x61, exp: 0 }; + round_nearest_tie_even(&mut fp, 6); + assert_eq!(fp.mant, 2); + + let mut fp = ExtendedFloat { mant: 0x21, exp: 0 }; + round_nearest_tie_even(&mut fp, 6); + assert_eq!(fp.mant, 1); + + // Check round-down, below halfway + let mut fp = ExtendedFloat { mant: 0x5F, exp: 0 }; + round_nearest_tie_even(&mut fp, 6); + assert_eq!(fp.mant, 1); + + let mut fp = ExtendedFloat { mant: 0x1F, exp: 0 }; + round_nearest_tie_even(&mut fp, 6); + assert_eq!(fp.mant, 0); +} + +// HIGH-LEVEL + +#[test] +fn round_to_float_test() { + // Denormal + let mut fp = ExtendedFloat { + mant: 1 << 63, + exp: f64::DENORMAL_EXPONENT - 15, + }; + round_to_float::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, 1 << 48); + assert_eq!(fp.exp, f64::DENORMAL_EXPONENT); + + // Halfway, round-down (b'1000000000000000000000000000000000000000000000000000010000000000') + let mut fp = ExtendedFloat { + mant: 0x8000000000000400, + exp: -63, + }; + round_to_float::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, 1 << 52); + assert_eq!(fp.exp, -52); + + // Halfway, round-up (b'1000000000000000000000000000000000000000000000000000110000000000') + let mut fp = ExtendedFloat { + mant: 0x8000000000000C00, + exp: -63, + }; + round_to_float::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, (1 << 52) + 2); + assert_eq!(fp.exp, -52); + + // Above halfway + let mut fp = ExtendedFloat { + mant: 0x8000000000000401, + exp: -63, + }; + round_to_float::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, (1 << 52) + 1); + assert_eq!(fp.exp, -52); + + let mut fp = ExtendedFloat { + mant: 0x8000000000000C01, + exp: -63, + }; + round_to_float::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, (1 << 52) + 2); + assert_eq!(fp.exp, -52); + + // Below halfway + let mut fp = ExtendedFloat { + mant: 0x80000000000003FF, + exp: -63, + }; + round_to_float::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, 1 << 52); + assert_eq!(fp.exp, -52); + + let mut fp = ExtendedFloat { + mant: 0x8000000000000BFF, + exp: -63, + }; + round_to_float::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, (1 << 52) + 1); + assert_eq!(fp.exp, -52); +} + +#[test] +fn avoid_overflow_test() { + // Avoid overflow, fails by 1 + let mut fp = ExtendedFloat { + mant: 0xFFFFFFFFFFFF, + exp: f64::MAX_EXPONENT + 5, + }; + avoid_overflow::<f64>(&mut fp); + assert_eq!(fp.mant, 0xFFFFFFFFFFFF); + assert_eq!(fp.exp, f64::MAX_EXPONENT + 5); + + // Avoid overflow, succeeds + let mut fp = ExtendedFloat { + mant: 0xFFFFFFFFFFFF, + exp: f64::MAX_EXPONENT + 4, + }; + avoid_overflow::<f64>(&mut fp); + assert_eq!(fp.mant, 0x1FFFFFFFFFFFE0); + assert_eq!(fp.exp, f64::MAX_EXPONENT - 1); +} + +#[test] +fn round_to_native_test() { + // Overflow + let mut fp = ExtendedFloat { + mant: 0xFFFFFFFFFFFF, + exp: f64::MAX_EXPONENT + 4, + }; + round_to_native::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, 0x1FFFFFFFFFFFE0); + assert_eq!(fp.exp, f64::MAX_EXPONENT - 1); + + // Need denormal + let mut fp = ExtendedFloat { + mant: 1, + exp: f64::DENORMAL_EXPONENT + 48, + }; + round_to_native::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, 1 << 48); + assert_eq!(fp.exp, f64::DENORMAL_EXPONENT); + + // Halfway, round-down (b'10000000000000000000000000000000000000000000000000000100000') + let mut fp = ExtendedFloat { + mant: 0x400000000000020, + exp: -58, + }; + round_to_native::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, 1 << 52); + assert_eq!(fp.exp, -52); + + // Halfway, round-up (b'10000000000000000000000000000000000000000000000000001100000') + let mut fp = ExtendedFloat { + mant: 0x400000000000060, + exp: -58, + }; + round_to_native::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, (1 << 52) + 2); + assert_eq!(fp.exp, -52); + + // Above halfway + let mut fp = ExtendedFloat { + mant: 0x400000000000021, + exp: -58, + }; + round_to_native::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, (1 << 52) + 1); + assert_eq!(fp.exp, -52); + + let mut fp = ExtendedFloat { + mant: 0x400000000000061, + exp: -58, + }; + round_to_native::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, (1 << 52) + 2); + assert_eq!(fp.exp, -52); + + // Below halfway + let mut fp = ExtendedFloat { + mant: 0x40000000000001F, + exp: -58, + }; + round_to_native::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, 1 << 52); + assert_eq!(fp.exp, -52); + + let mut fp = ExtendedFloat { + mant: 0x40000000000005F, + exp: -58, + }; + round_to_native::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, (1 << 52) + 1); + assert_eq!(fp.exp, -52); + + // Underflow + // Adapted from failures in strtod. + let mut fp = ExtendedFloat { + exp: -1139, + mant: 18446744073709550712, + }; + round_to_native::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, 0); + assert_eq!(fp.exp, 0); + + let mut fp = ExtendedFloat { + exp: -1139, + mant: 18446744073709551460, + }; + round_to_native::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, 0); + assert_eq!(fp.exp, 0); + + let mut fp = ExtendedFloat { + exp: -1138, + mant: 9223372036854776103, + }; + round_to_native::<f64, _>(&mut fp, round_nearest_tie_even); + assert_eq!(fp.mant, 1); + assert_eq!(fp.exp, -1074); +} |