libm: Flatten the `libm/libm` directory

1 files changed, 37 insertions, 0 deletions

diff --git a/library/compiler-builtins/libm/src/math/nextafterf.rs b/library/compiler-builtins/libm/src/math/nextafterf.rs
new file mode 100644
index 00000000000..8ba3833562f
--- /dev/null
+++ b/library/compiler-builtins/libm/src/math/nextafterf.rs
@@ -0,0 +1,37 @@
+#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
+pub fn nextafterf(x: f32, y: f32) -> f32 {
+    if x.is_nan() || y.is_nan() {
+        return x + y;
+    }
+
+    let mut ux_i = x.to_bits();
+    let uy_i = y.to_bits();
+    if ux_i == uy_i {
+        return y;
+    }
+
+    let ax = ux_i & 0x7fff_ffff_u32;
+    let ay = uy_i & 0x7fff_ffff_u32;
+    if ax == 0 {
+        if ay == 0 {
+            return y;
+        }
+        ux_i = (uy_i & 0x8000_0000_u32) | 1;
+    } else if ax > ay || ((ux_i ^ uy_i) & 0x8000_0000_u32) != 0 {
+        ux_i -= 1;
+    } else {
+        ux_i += 1;
+    }
+
+    let e = ux_i & 0x7f80_0000_u32;
+    // raise overflow if ux_f is infinite and x is finite
+    if e == 0x7f80_0000_u32 {
+        force_eval!(x + x);
+    }
+    let ux_f = f32::from_bits(ux_i);
+    // raise underflow if ux_f is subnormal or zero
+    if e == 0 {
+        force_eval!(x * x + ux_f * ux_f);
+    }
+    ux_f
+}