Auto merge of #141669 - tgross35:float-test-cleanup, r=<try>

float: Replace some approximate assertions with exact

As was mentioned at [1], we currently use `assert_approx_eq` for testing
some math functions that guarantee exact results. Replace approximate
assertions with exact ones for the following:

* `ceil`
* `floor`
* `fract`
* `from_bits`
* `mul_add`
* `round_ties_even`
* `round`
* `trunc`

This likely wasn't done in the past to avoid writing out exact decimals
that don't match the intuitive answer (e.g. 1.3 - 1.0 = 0.300...004),
but ensuring our results are accurate seems more important here.

[1]: #138087 (comment)

The first commit is a small bit of macro cleanup.

try-job: aarch64-gnu

Author: bors

library/coretests/tests/floats/f128.rs

@@ -39,17 +39,6 @@ const NAN_MASK1: u128 = 0x0000aaaaaaaaaaaaaaaaaaaaaaaaaaaa;
 /// Second pattern over the mantissa
 const NAN_MASK2: u128 = 0x00005555555555555555555555555555;
 
-/// Compare by representation
-#[allow(unused_macros)]
-macro_rules! assert_f128_biteq {
-    ($a:expr, $b:expr) => {
-        let (l, r): (&f128, &f128) = (&$a, &$b);
-        let lb = l.to_bits();
-        let rb = r.to_bits();
-        assert_eq!(lb, rb, "float {l:?} is not bitequal to {r:?}.\na: {lb:#034x}\nb: {rb:#034x}");
-    };
-}
-
 #[test]
 fn test_num_f128() {
     // FIXME(f16_f128): replace with a `test_num` call once the required `fmodl`/`fmodf128`
@@ -260,98 +249,98 @@ fn test_classify() {
 #[cfg(not(miri))]
 #[cfg(target_has_reliable_f128_math)]
 fn test_floor() {
-    assert_approx_eq!(1.0f128.floor(), 1.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.3f128.floor(), 1.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.5f128.floor(), 1.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.7f128.floor(), 1.0f128, TOL_PRECISE);
-    assert_approx_eq!(0.0f128.floor(), 0.0f128, TOL_PRECISE);
-    assert_approx_eq!((-0.0f128).floor(), -0.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.0f128).floor(), -1.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.3f128).floor(), -2.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.5f128).floor(), -2.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.7f128).floor(), -2.0f128, TOL_PRECISE);
+    assert_eq!(1.0f128.floor(), 1.0f128);
+    assert_eq!(1.3f128.floor(), 1.0f128);
+    assert_eq!(1.5f128.floor(), 1.0f128);
+    assert_eq!(1.7f128.floor(), 1.0f128);
+    assert_eq!(0.0f128.floor(), 0.0f128);
+    assert_eq!((-0.0f128).floor(), -0.0f128);
+    assert_eq!((-1.0f128).floor(), -1.0f128);
+    assert_eq!((-1.3f128).floor(), -2.0f128);
+    assert_eq!((-1.5f128).floor(), -2.0f128);
+    assert_eq!((-1.7f128).floor(), -2.0f128);
 }
 
 #[test]
 #[cfg(not(miri))]
 #[cfg(target_has_reliable_f128_math)]
 fn test_ceil() {
-    assert_approx_eq!(1.0f128.ceil(), 1.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.3f128.ceil(), 2.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.5f128.ceil(), 2.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.7f128.ceil(), 2.0f128, TOL_PRECISE);
-    assert_approx_eq!(0.0f128.ceil(), 0.0f128, TOL_PRECISE);
-    assert_approx_eq!((-0.0f128).ceil(), -0.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.0f128).ceil(), -1.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.3f128).ceil(), -1.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.5f128).ceil(), -1.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.7f128).ceil(), -1.0f128, TOL_PRECISE);
+    assert_eq!(1.0f128.ceil(), 1.0f128);
+    assert_eq!(1.3f128.ceil(), 2.0f128);
+    assert_eq!(1.5f128.ceil(), 2.0f128);
+    assert_eq!(1.7f128.ceil(), 2.0f128);
+    assert_eq!(0.0f128.ceil(), 0.0f128);
+    assert_eq!((-0.0f128).ceil(), -0.0f128);
+    assert_eq!((-1.0f128).ceil(), -1.0f128);
+    assert_eq!((-1.3f128).ceil(), -1.0f128);
+    assert_eq!((-1.5f128).ceil(), -1.0f128);
+    assert_eq!((-1.7f128).ceil(), -1.0f128);
 }
 
 #[test]
 #[cfg(not(miri))]
 #[cfg(target_has_reliable_f128_math)]
 fn test_round() {
-    assert_approx_eq!(2.5f128.round(), 3.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.0f128.round(), 1.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.3f128.round(), 1.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.5f128.round(), 2.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.7f128.round(), 2.0f128, TOL_PRECISE);
-    assert_approx_eq!(0.0f128.round(), 0.0f128, TOL_PRECISE);
-    assert_approx_eq!((-0.0f128).round(), -0.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.0f128).round(), -1.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.3f128).round(), -1.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.5f128).round(), -2.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.7f128).round(), -2.0f128, TOL_PRECISE);
+    assert_eq!(2.5f128.round(), 3.0f128);
+    assert_eq!(1.0f128.round(), 1.0f128);
+    assert_eq!(1.3f128.round(), 1.0f128);
+    assert_eq!(1.5f128.round(), 2.0f128);
+    assert_eq!(1.7f128.round(), 2.0f128);
+    assert_eq!(0.0f128.round(), 0.0f128);
+    assert_eq!((-0.0f128).round(), -0.0f128);
+    assert_eq!((-1.0f128).round(), -1.0f128);
+    assert_eq!((-1.3f128).round(), -1.0f128);
+    assert_eq!((-1.5f128).round(), -2.0f128);
+    assert_eq!((-1.7f128).round(), -2.0f128);
 }
 
 #[test]
 #[cfg(not(miri))]
 #[cfg(target_has_reliable_f128_math)]
 fn test_round_ties_even() {
-    assert_approx_eq!(2.5f128.round_ties_even(), 2.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.0f128.round_ties_even(), 1.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.3f128.round_ties_even(), 1.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.5f128.round_ties_even(), 2.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.7f128.round_ties_even(), 2.0f128, TOL_PRECISE);
-    assert_approx_eq!(0.0f128.round_ties_even(), 0.0f128, TOL_PRECISE);
-    assert_approx_eq!((-0.0f128).round_ties_even(), -0.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.0f128).round_ties_even(), -1.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.3f128).round_ties_even(), -1.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.5f128).round_ties_even(), -2.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.7f128).round_ties_even(), -2.0f128, TOL_PRECISE);
+    assert_eq!(2.5f128.round_ties_even(), 2.0f128);
+    assert_eq!(1.0f128.round_ties_even(), 1.0f128);
+    assert_eq!(1.3f128.round_ties_even(), 1.0f128);
+    assert_eq!(1.5f128.round_ties_even(), 2.0f128);
+    assert_eq!(1.7f128.round_ties_even(), 2.0f128);
+    assert_eq!(0.0f128.round_ties_even(), 0.0f128);
+    assert_eq!((-0.0f128).round_ties_even(), -0.0f128);
+    assert_eq!((-1.0f128).round_ties_even(), -1.0f128);
+    assert_eq!((-1.3f128).round_ties_even(), -1.0f128);
+    assert_eq!((-1.5f128).round_ties_even(), -2.0f128);
+    assert_eq!((-1.7f128).round_ties_even(), -2.0f128);
 }
 
 #[test]
 #[cfg(not(miri))]
 #[cfg(target_has_reliable_f128_math)]
 fn test_trunc() {
-    assert_approx_eq!(1.0f128.trunc(), 1.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.3f128.trunc(), 1.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.5f128.trunc(), 1.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.7f128.trunc(), 1.0f128, TOL_PRECISE);
-    assert_approx_eq!(0.0f128.trunc(), 0.0f128, TOL_PRECISE);
-    assert_approx_eq!((-0.0f128).trunc(), -0.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.0f128).trunc(), -1.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.3f128).trunc(), -1.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.5f128).trunc(), -1.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.7f128).trunc(), -1.0f128, TOL_PRECISE);
+    assert_eq!(1.0f128.trunc(), 1.0f128);
+    assert_eq!(1.3f128.trunc(), 1.0f128);
+    assert_eq!(1.5f128.trunc(), 1.0f128);
+    assert_eq!(1.7f128.trunc(), 1.0f128);
+    assert_eq!(0.0f128.trunc(), 0.0f128);
+    assert_eq!((-0.0f128).trunc(), -0.0f128);
+    assert_eq!((-1.0f128).trunc(), -1.0f128);
+    assert_eq!((-1.3f128).trunc(), -1.0f128);
+    assert_eq!((-1.5f128).trunc(), -1.0f128);
+    assert_eq!((-1.7f128).trunc(), -1.0f128);
 }
 
 #[test]
 #[cfg(not(miri))]
 #[cfg(target_has_reliable_f128_math)]
 fn test_fract() {
-    assert_approx_eq!(1.0f128.fract(), 0.0f128, TOL_PRECISE);
-    assert_approx_eq!(1.3f128.fract(), 0.3f128, TOL_PRECISE);
-    assert_approx_eq!(1.5f128.fract(), 0.5f128, TOL_PRECISE);
-    assert_approx_eq!(1.7f128.fract(), 0.7f128, TOL_PRECISE);
-    assert_approx_eq!(0.0f128.fract(), 0.0f128, TOL_PRECISE);
-    assert_approx_eq!((-0.0f128).fract(), -0.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.0f128).fract(), -0.0f128, TOL_PRECISE);
-    assert_approx_eq!((-1.3f128).fract(), -0.3f128, TOL_PRECISE);
-    assert_approx_eq!((-1.5f128).fract(), -0.5f128, TOL_PRECISE);
-    assert_approx_eq!((-1.7f128).fract(), -0.7f128, TOL_PRECISE);
+    assert_eq!(1.0f128.fract(), 0.0f128);
+    assert_eq!(1.3f128.fract(), 0.300000000000000044408920985006261617f128);
+    assert_eq!(1.5f128.fract(), 0.5f128);
+    assert_eq!(1.7f128.fract(), 0.7f128);
+    assert_eq!(0.0f128.fract(), 0.0f128);
+    assert_eq!((-0.0f128).fract(), -0.0f128);
+    assert_eq!((-1.0f128).fract(), -0.0f128);
+    assert_eq!((-1.3f128).fract(), -0.300000000000000044408920985006261617f128);
+    assert_eq!((-1.5f128).fract(), -0.5f128);
+    assert_eq!((-1.7f128).fract(), -0.699999999999999955591079014993738383f128);
 }
 
 #[test]
@@ -401,27 +390,27 @@ fn test_next_up() {
     let max_down = f128::from_bits(MAX_DOWN_BITS);
     let largest_subnormal = f128::from_bits(LARGEST_SUBNORMAL_BITS);
     let smallest_normal = f128::from_bits(SMALLEST_NORMAL_BITS);
-    assert_f128_biteq!(f128::NEG_INFINITY.next_up(), f128::MIN);
-    assert_f128_biteq!(f128::MIN.next_up(), -max_down);
-    assert_f128_biteq!((-1.0 - f128::EPSILON).next_up(), -1.0);
-    assert_f128_biteq!((-smallest_normal).next_up(), -largest_subnormal);
-    assert_f128_biteq!((-tiny_up).next_up(), -tiny);
-    assert_f128_biteq!((-tiny).next_up(), -0.0f128);
-    assert_f128_biteq!((-0.0f128).next_up(), tiny);
-    assert_f128_biteq!(0.0f128.next_up(), tiny);
-    assert_f128_biteq!(tiny.next_up(), tiny_up);
-    assert_f128_biteq!(largest_subnormal.next_up(), smallest_normal);
-    assert_f128_biteq!(1.0f128.next_up(), 1.0 + f128::EPSILON);
-    assert_f128_biteq!(f128::MAX.next_up(), f128::INFINITY);
-    assert_f128_biteq!(f128::INFINITY.next_up(), f128::INFINITY);
+    assert_biteq!(f128::NEG_INFINITY.next_up(), f128::MIN);
+    assert_biteq!(f128::MIN.next_up(), -max_down);
+    assert_biteq!((-1.0 - f128::EPSILON).next_up(), -1.0f128);
+    assert_biteq!((-smallest_normal).next_up(), -largest_subnormal);
+    assert_biteq!((-tiny_up).next_up(), -tiny);
+    assert_biteq!((-tiny).next_up(), -0.0f128);
+    assert_biteq!((-0.0f128).next_up(), tiny);
+    assert_biteq!(0.0f128.next_up(), tiny);
+    assert_biteq!(tiny.next_up(), tiny_up);
+    assert_biteq!(largest_subnormal.next_up(), smallest_normal);
+    assert_biteq!(1.0f128.next_up(), 1.0 + f128::EPSILON);
+    assert_biteq!(f128::MAX.next_up(), f128::INFINITY);
+    assert_biteq!(f128::INFINITY.next_up(), f128::INFINITY);
 
     // Check that NaNs roundtrip.
     let nan0 = f128::NAN;
     let nan1 = f128::from_bits(f128::NAN.to_bits() ^ 0x002a_aaaa);
     let nan2 = f128::from_bits(f128::NAN.to_bits() ^ 0x0055_5555);
-    assert_f128_biteq!(nan0.next_up(), nan0);
-    assert_f128_biteq!(nan1.next_up(), nan1);
-    assert_f128_biteq!(nan2.next_up(), nan2);
+    assert_biteq!(nan0.next_up(), nan0);
+    assert_biteq!(nan1.next_up(), nan1);
+    assert_biteq!(nan2.next_up(), nan2);
 }
 
 #[test]
@@ -431,28 +420,28 @@ fn test_next_down() {
     let max_down = f128::from_bits(MAX_DOWN_BITS);
     let largest_subnormal = f128::from_bits(LARGEST_SUBNORMAL_BITS);
     let smallest_normal = f128::from_bits(SMALLEST_NORMAL_BITS);
-    assert_f128_biteq!(f128::NEG_INFINITY.next_down(), f128::NEG_INFINITY);
-    assert_f128_biteq!(f128::MIN.next_down(), f128::NEG_INFINITY);
-    assert_f128_biteq!((-max_down).next_down(), f128::MIN);
-    assert_f128_biteq!((-1.0f128).next_down(), -1.0 - f128::EPSILON);
-    assert_f128_biteq!((-largest_subnormal).next_down(), -smallest_normal);
-    assert_f128_biteq!((-tiny).next_down(), -tiny_up);
-    assert_f128_biteq!((-0.0f128).next_down(), -tiny);
-    assert_f128_biteq!((0.0f128).next_down(), -tiny);
-    assert_f128_biteq!(tiny.next_down(), 0.0f128);
-    assert_f128_biteq!(tiny_up.next_down(), tiny);
-    assert_f128_biteq!(smallest_normal.next_down(), largest_subnormal);
-    assert_f128_biteq!((1.0 + f128::EPSILON).next_down(), 1.0f128);
-    assert_f128_biteq!(f128::MAX.next_down(), max_down);
-    assert_f128_biteq!(f128::INFINITY.next_down(), f128::MAX);
+    assert_biteq!(f128::NEG_INFINITY.next_down(), f128::NEG_INFINITY);
+    assert_biteq!(f128::MIN.next_down(), f128::NEG_INFINITY);
+    assert_biteq!((-max_down).next_down(), f128::MIN);
+    assert_biteq!((-1.0f128).next_down(), -1.0 - f128::EPSILON);
+    assert_biteq!((-largest_subnormal).next_down(), -smallest_normal);
+    assert_biteq!((-tiny).next_down(), -tiny_up);
+    assert_biteq!((-0.0f128).next_down(), -tiny);
+    assert_biteq!((0.0f128).next_down(), -tiny);
+    assert_biteq!(tiny.next_down(), 0.0f128);
+    assert_biteq!(tiny_up.next_down(), tiny);
+    assert_biteq!(smallest_normal.next_down(), largest_subnormal);
+    assert_biteq!((1.0 + f128::EPSILON).next_down(), 1.0f128);
+    assert_biteq!(f128::MAX.next_down(), max_down);
+    assert_biteq!(f128::INFINITY.next_down(), f128::MAX);
 
     // Check that NaNs roundtrip.
     let nan0 = f128::NAN;
     let nan1 = f128::from_bits(f128::NAN.to_bits() ^ 0x002a_aaaa);
     let nan2 = f128::from_bits(f128::NAN.to_bits() ^ 0x0055_5555);
-    assert_f128_biteq!(nan0.next_down(), nan0);
-    assert_f128_biteq!(nan1.next_down(), nan1);
-    assert_f128_biteq!(nan2.next_down(), nan2);
+    assert_biteq!(nan0.next_down(), nan0);
+    assert_biteq!(nan1.next_down(), nan1);
+    assert_biteq!(nan2.next_down(), nan2);
 }
 
 #[test]
@@ -462,10 +451,10 @@ fn test_mul_add() {
     let nan: f128 = f128::NAN;
     let inf: f128 = f128::INFINITY;
     let neg_inf: f128 = f128::NEG_INFINITY;
-    assert_approx_eq!(12.3f128.mul_add(4.5, 6.7), 62.05, TOL_PRECISE);
-    assert_approx_eq!((-12.3f128).mul_add(-4.5, -6.7), 48.65, TOL_PRECISE);
-    assert_approx_eq!(0.0f128.mul_add(8.9, 1.2), 1.2, TOL_PRECISE);
-    assert_approx_eq!(3.4f128.mul_add(-0.0, 5.6), 5.6, TOL_PRECISE);
+    assert_eq!(12.3f128.mul_add(4.5, 6.7), 62.0500000000000033750779948604758829);
+    assert_eq!((-12.3f128).mul_add(-4.5, -6.7), 48.65000000000000301980662698042579);
+    assert_eq!(0.0f128.mul_add(8.9, 1.2), 1.2);
+    assert_eq!(3.4f128.mul_add(-0.0, 5.6), 5.6);
     assert!(nan.mul_add(7.8, 9.0).is_nan());
     assert_eq!(inf.mul_add(7.8, 9.0), inf);
     assert_eq!(neg_inf.mul_add(7.8, 9.0), neg_inf);
@@ -561,10 +550,10 @@ fn test_float_bits_conv() {
     assert_eq!((12.5f128).to_bits(), 0x40029000000000000000000000000000);
     assert_eq!((1337f128).to_bits(), 0x40094e40000000000000000000000000);
     assert_eq!((-14.25f128).to_bits(), 0xc002c800000000000000000000000000);
-    assert_approx_eq!(f128::from_bits(0x3fff0000000000000000000000000000), 1.0, TOL_PRECISE);
-    assert_approx_eq!(f128::from_bits(0x40029000000000000000000000000000), 12.5, TOL_PRECISE);
-    assert_approx_eq!(f128::from_bits(0x40094e40000000000000000000000000), 1337.0, TOL_PRECISE);
-    assert_approx_eq!(f128::from_bits(0xc002c800000000000000000000000000), -14.25, TOL_PRECISE);
+    assert_eq!(f128::from_bits(0x3fff0000000000000000000000000000), 1.0);
+    assert_eq!(f128::from_bits(0x40029000000000000000000000000000), 12.5);
+    assert_eq!(f128::from_bits(0x40094e40000000000000000000000000), 1337.0);
+    assert_eq!(f128::from_bits(0xc002c800000000000000000000000000), -14.25);
 
     // Check that NaNs roundtrip their bits regardless of signaling-ness
     // 0xA is 0b1010; 0x5 is 0b0101 -- so these two together clobbers all the mantissa bits