1 files changed, 180 insertions, 0 deletions
diff --git a/third_party/rust/ryu/tests/f2s_test.rs b/third_party/rust/ryu/tests/f2s_test.rs
new file mode 100644
index 0000000000..927fa7e4b1
--- /dev/null
+++ b/third_party/rust/ryu/tests/f2s_test.rs
@@ -0,0 +1,180 @@
+// Translated from C to Rust. The original C code can be found at
+// https://github.com/ulfjack/ryu and carries the following license:
+//
+// Copyright 2018 Ulf Adams
+//
+// The contents of this file may be used under the terms of the Apache License,
+// Version 2.0.
+//
+//    (See accompanying file LICENSE-Apache or copy at
+//     http://www.apache.org/licenses/LICENSE-2.0)
+//
+// Alternatively, the contents of this file may be used under the terms of
+// the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE-Boost or copy at
+//     https://www.boost.org/LICENSE_1_0.txt)
+//
+// Unless required by applicable law or agreed to in writing, this software
+// is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.
+
+#![allow(
+    clippy::approx_constant,
+    clippy::float_cmp,
+    clippy::non_ascii_literal,
+    clippy::unreadable_literal,
+    clippy::unseparated_literal_suffix
+)]
+
+#[macro_use]
+mod macros;
+
+use std::f32;
+
+fn pretty(f: f32) -> String {
+    ryu::Buffer::new().format(f).to_owned()
+}
+
+#[test]
+fn test_ryu() {
+    check!(0.3);
+    check!(1234000000000.0);
+    check!(1.234e13);
+    check!(2.71828);
+    check!(1.1e32);
+    check!(1.1e-32);
+    check!(2.7182817);
+    check!(1e-45);
+    check!(3.4028235e38);
+    check!(-0.001234);
+}
+
+#[test]
+fn test_random() {
+    let n = if cfg!(miri) { 100 } else { 1000000 };
+    let mut buffer = ryu::Buffer::new();
+    for _ in 0..n {
+        let f: f32 = rand::random();
+        assert_eq!(f, buffer.format_finite(f).parse().unwrap());
+    }
+}
+
+#[test]
+#[cfg_attr(miri, ignore)]
+fn test_non_finite() {
+    for i in 0u32..1 << 23 {
+        let f = f32::from_bits((((1 << 8) - 1) << 23) + i);
+        assert!(!f.is_finite(), "f={}", f);
+        ryu::Buffer::new().format_finite(f);
+    }
+}
+
+#[test]
+fn test_basic() {
+    check!(0.0);
+    check!(-0.0);
+    check!(1.0);
+    check!(-1.0);
+    assert_eq!(pretty(f32::NAN), "NaN");
+    assert_eq!(pretty(f32::INFINITY), "inf");
+    assert_eq!(pretty(f32::NEG_INFINITY), "-inf");
+}
+
+#[test]
+fn test_switch_to_subnormal() {
+    check!(1.1754944e-38);
+}
+
+#[test]
+fn test_min_and_max() {
+    assert_eq!(f32::from_bits(0x7f7fffff), 3.4028235e38);
+    check!(3.4028235e38);
+    assert_eq!(f32::from_bits(1), 1e-45);
+    check!(1e-45);
+}
+
+// Check that we return the exact boundary if it is the shortest
+// representation, but only if the original floating point number is even.
+#[test]
+fn test_boundary_round_even() {
+    check!(33554450.0);
+    check!(9000000000.0);
+    check!(34366720000.0);
+}
+
+// If the exact value is exactly halfway between two shortest representations,
+// then we round to even. It seems like this only makes a difference if the
+// last two digits are ...2|5 or ...7|5, and we cut off the 5.
+#[test]
+fn test_exact_value_round_even() {
+    check!(305404.12);
+    check!(8099.0312);
+}
+
+#[test]
+fn test_lots_of_trailing_zeros() {
+    // Pattern for the first test: 00111001100000000000000000000000
+    check!(0.00024414062);
+    check!(0.0024414062);
+    check!(0.0043945312);
+    check!(0.0063476562);
+}
+
+#[test]
+fn test_regression() {
+    check!(4.7223665e21);
+    check!(8388608.0);
+    check!(16777216.0);
+    check!(33554436.0);
+    check!(67131496.0);
+    check!(1.9310392e-38);
+    check!(-2.47e-43);
+    check!(1.993244e-38);
+    check!(4103.9004);
+    check!(5339999700.0);
+    check!(6.0898e-39);
+    check!(0.0010310042);
+    check!(2.882326e17);
+    check!(7.038531e-26);
+    check!(9.223404e17);
+    check!(67108870.0);
+    check!(1e-44);
+    check!(2.816025e14);
+    check!(9.223372e18);
+    check!(1.5846086e29);
+    check!(1.1811161e19);
+    check!(5.368709e18);
+    check!(4.6143166e18);
+    check!(0.007812537);
+    check!(1e-45);
+    check!(1.18697725e20);
+    check!(1.00014165e-36);
+    check!(200.0);
+    check!(33554432.0);
+}
+
+#[test]
+fn test_looks_like_pow5() {
+    // These numbers have a mantissa that is the largest power of 5 that fits,
+    // and an exponent that causes the computation for q to result in 10, which
+    // is a corner case for Ryū.
+    assert_eq!(f32::from_bits(0x5D1502F9), 6.7108864e17);
+    check!(6.7108864e17);
+    assert_eq!(f32::from_bits(0x5D9502F9), 1.3421773e18);
+    check!(1.3421773e18);
+    assert_eq!(f32::from_bits(0x5E1502F9), 2.6843546e18);
+    check!(2.6843546e18);
+}
+
+#[test]
+fn test_output_length() {
+    check!(1.0); // already tested in Basic
+    check!(1.2);
+    check!(1.23);
+    check!(1.234);
+    check!(1.2345);
+    check!(1.23456);
+    check!(1.234567);
+    check!(1.2345678);
+    check!(1.23456735e-36);
+}