     1
     2
     3
     4
     5
     6
     7
     8
     9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41

    use core::f64;

    const TOINT: f64 = 1. / f64::EPSILON;

    /// Floor (f64)
    ///
    /// Finds the nearest integer less than or equal to `x`.
    #[inline]
    #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
    pub fn floor(x: f64) -> f64 {
        // On wasm32 we know that LLVM's intrinsic will compile to an optimized
        // `f64.floor` native instruction, so we can leverage this for both code size
        // and speed.
        llvm_intrinsically_optimized! {
            #[cfg(target_arch = "wasm32")] {
                return unsafe { ::core::intrinsics::floorf64(x) }
            }
        }
        let ui = x.to_bits();
        let e = ((ui >> 52) & 0x7ff) as i32;

        if (e >= 0x3ff + 52) || (x == 0.) {
            return x;
        }
        /* y = int(x) - x, where int(x) is an integer neighbor of x */
        let y = if (ui >> 63) != 0 {
            x - TOINT + TOINT - x
        } else {
            x + TOINT - TOINT - x
        };
        /* special case because of non-nearest rounding modes */
        if e < 0x3ff {
            force_eval!(y);
            return if (ui >> 63) != 0 { -1. } else { 0. };
        }
        if y > 0. {
            x + y - 1.
        } else {
            x + y
        }
    }

# Help

## Keyboard Shortcuts

`?`
  Show this help dialog
`S`
  Focus the search field
`↑`
  Move up in search results
`↓`
  Move down in search results
`↹`
  Switch tab
`⏎`
  Go to active search result
`+`
  Expand all sections
`-`
  Collapse all sections

## Search Tricks

Prefix searches with a type followed by a colon (e.g., `fn:`) to restrict the search to a given type.

Accepted types are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.

Search functions by type signature (e.g., `vec -> usize` or `* -> vec`)

Search multiple things at once by splitting your query with comma (e.g., `str,u8` or `String,struct:Vec,test`)