holey-bytes/hbvm/src/float/riscv64.rs

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use {core::arch::asm, hbbytecode::RoundingMode};
macro_rules! roundm_op_litmode_internal {
($ins:literal, $in:expr, $out:expr => $outy:ident, $mode:literal $(,)?) => {
asm!(
concat!($ins, " {}, {}, ", $mode),
out($outy) $out,
in(freg) $in,
)
};
}
macro_rules! gen_roundm_op_litmode {
[$($ty:ident => $reg:ident),* $(,)?] => {
macro_rules! roundm_op_litmode {
$(
($ins:literal, $in:expr, $out:expr => $ty, $mode:literal) => {
roundm_op_litmode_internal!($ins, $in, $out => $reg, $mode)
};
)*
}
};
}
gen_roundm_op_litmode![
f32 => freg,
f64 => freg,
i64 => reg,
];
macro_rules! fnsdef {
{$(
$(#[$attr:meta])*
$vis:vis fn $name:ident($from:ident -> $to:ident): $ins:literal;
)*} => {$(
$(#[$attr])*
$vis fn $name(val: $from, mode: RoundingMode) -> $to {
let result: $to;
unsafe {
match mode {
RoundingMode::NearestEven => roundm_op_litmode!($ins, val, result => $to, "rne"),
RoundingMode::Truncate => roundm_op_litmode!($ins, val, result => $to, "rtz"),
RoundingMode::Up => roundm_op_litmode!($ins, val, result => $to, "rup"),
RoundingMode::Down => roundm_op_litmode!($ins, val, result => $to, "rdn"),
}
}
result
}
)*};
}
fnsdef! {
/// Convert [`f64`] to [`f32`] with chosen rounding mode
pub fn conv64to32(f64 -> f32): "fcvt.s.d";
/// Convert [`f32`] to [`i64`] with chosen rounding mode
pub fn f32toint(f32 -> i64): "fcvt.l.s";
/// Convert [`f64`] to [`i64`] with chosen rounding mode
pub fn f64toint(f64 -> i64): "fcvt.l.d";
}