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use abi::call::{ArgAttribute, FnType, PassMode, Reg, RegKind};
use abi::{self, HasDataLayout, LayoutOf, TyLayout, TyLayoutMethods};
use spec::HasTargetSpec;
#[derive(PartialEq)]
pub enum Flavor {
General,
Fastcall
}
fn is_single_fp_element<'a, Ty, C>(cx: C, layout: TyLayout<'a, Ty>) -> bool
where Ty: TyLayoutMethods<'a, C> + Copy,
C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
{
match layout.abi {
abi::Abi::Scalar(ref scalar) => scalar.value.is_float(),
abi::Abi::Aggregate { .. } => {
if layout.fields.count() == 1 && layout.fields.offset(0).bytes() == 0 {
is_single_fp_element(cx, layout.field(cx, 0))
} else {
false
}
}
_ => false
}
}
pub fn compute_abi_info<'a, Ty, C>(cx: C, fty: &mut FnType<'a, Ty>, flavor: Flavor)
where Ty: TyLayoutMethods<'a, C> + Copy,
C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout + HasTargetSpec
{
if !fty.ret.is_ignore() {
if fty.ret.layout.is_aggregate() {
let t = cx.target_spec();
if t.options.abi_return_struct_as_int {
if !t.options.is_like_msvc && is_single_fp_element(cx, fty.ret.layout) {
match fty.ret.layout.size.bytes() {
4 => fty.ret.cast_to(Reg::f32()),
8 => fty.ret.cast_to(Reg::f64()),
_ => fty.ret.make_indirect()
}
} else {
match fty.ret.layout.size.bytes() {
1 => fty.ret.cast_to(Reg::i8()),
2 => fty.ret.cast_to(Reg::i16()),
4 => fty.ret.cast_to(Reg::i32()),
8 => fty.ret.cast_to(Reg::i64()),
_ => fty.ret.make_indirect()
}
}
} else {
fty.ret.make_indirect();
}
} else {
fty.ret.extend_integer_width_to(32);
}
}
for arg in &mut fty.args {
if arg.is_ignore() { continue; }
if arg.layout.is_aggregate() {
arg.make_indirect_byval();
} else {
arg.extend_integer_width_to(32);
}
}
if flavor == Flavor::Fastcall {
let mut free_regs = 2;
for arg in &mut fty.args {
let attrs = match arg.mode {
PassMode::Ignore |
PassMode::Indirect(_, None) => continue,
PassMode::Direct(ref mut attrs) => attrs,
PassMode::Pair(..) |
PassMode::Indirect(_, Some(_)) |
PassMode::Cast(_) => {
unreachable!("x86 shouldn't be passing arguments by {:?}", arg.mode)
}
};
let unit = arg.layout.homogeneous_aggregate(cx).unwrap();
assert_eq!(unit.size, arg.layout.size);
if unit.kind == RegKind::Float {
continue;
}
let size_in_regs = (arg.layout.size.bits() + 31) / 32;
if size_in_regs == 0 {
continue;
}
if size_in_regs > free_regs {
break;
}
free_regs -= size_in_regs;
if arg.layout.size.bits() <= 32 && unit.kind == RegKind::Integer {
attrs.set(ArgAttribute::InReg);
}
if free_regs == 0 {
break;
}
}
}
}