Zig 0.17.0-dev (Split by item)

Shortcut keys
?
Show these tips
S
Focus search field
Esc
Clear focus & close tips
U
Jump to source code
↑
Move up in search results
↓
Move down in search results
↵
Go to active search result
This is an example of documentation generated by ZigDoc, an alternative to Zig's built-in Auto Doc feature. See also examples in other modes/formats. The project being documented here (as the example) is the Zig standard library. Public Function

convertFast

Public Function
std.fmt.parse_float.convert_fast.convertFast
pub fn convertFast(comptime T: type, n: Number(T)) ?T

Params

File

fmt/parse_float/convert_fast.zig:105
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
pub fn convertFast(comptime T: type, n: Number(T)) ?T {
    const MantissaT = common.mantissaType(T);

    if (!isFastPath(T, n)) {
        return null;
    }

    // TODO: x86 (no SSE/SSE2) requires x87 FPU to be setup correctly with fldcw
    const info = FloatInfo.from(T);

    var value: T = 0;
    if (n.exponent <= info.max_exponent_fast_path) {
        // normal fast path
        value = @as(T, @floatFromInt(n.mantissa));
        value = if (n.exponent < 0)
            value / fastPow10(T, @as(usize, @intCast(-n.exponent)))
        else
            value * fastPow10(T, @as(usize, @intCast(n.exponent)));
    } else {
        // disguised fast path
        const shift = n.exponent - info.max_exponent_fast_path;
        const mantissa = math.mul(MantissaT, n.mantissa, fastIntPow10(MantissaT, @as(usize, @intCast(shift)))) catch return null;
        if (mantissa > info.max_mantissa_fast_path) {
            return null;
        }
        value = @as(T, @floatFromInt(mantissa)) * fastPow10(T, info.max_exponent_fast_path);
    }

    if (n.negative) {
        value = -value;
    }
    return value;
}