pub fn log10_int(x: anytype) std.math.Log2Int(@TypeOf(x))x41
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75pub fn log10_int(x: anytype) std.math.Log2Int(@TypeOf(x)) {
const T = @TypeOf(x);
const OutT = std.math.Log2Int(T);
if (@typeInfo(T) != .int or @typeInfo(T).int.signedness != .unsigned)
@compileError("log10_int requires an unsigned integer, found " ++ @typeName(T));
std.debug.assert(x != 0);
const bit_size = @typeInfo(T).int.bits;
if (bit_size <= 8) {
return @as(OutT, @intCast(log10_int_u8(x)));
} else if (bit_size <= 16) {
return @as(OutT, @intCast(less_than_5(x)));
}
var val = x;
var log: u32 = 0;
inline for (0..11) |i| {
// Unnecessary branches should be removed by the compiler
if (bit_size > (1 << (11 - i)) * 5 * @log2(10.0) and val >= pow10((1 << (11 - i)) * 5)) {
const num_digits = (1 << (11 - i)) * 5;
val /= pow10(num_digits);
log += num_digits;
}
}
if (val >= pow10(5)) {
val /= pow10(5);
log += 5;
}
return @as(OutT, @intCast(log + less_than_5(@as(u32, @intCast(val)))));
}
Return the log base 10 of integer value x, rounding down to the nearest integer.