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use llvm::{Integer, Pointer, Float, Double, Struct, Vector, Array};
use abi::{self, FnType, ArgType};
use context::CrateContext;
use type_::Type;
fn ty_size(ty: Type) -> usize {
if ty.kind() == Vector {
bug!("ty_size: unhandled type")
} else {
abi::ty_size(ty, 8)
}
}
fn is_homogenous_aggregate_ty(ty: Type) -> Option<(Type, u64)> {
fn check_array(ty: Type) -> Option<(Type, u64)> {
let len = ty.array_length() as u64;
if len == 0 {
return None
}
let elt = ty.element_type();
is_homogenous_aggregate_ty(elt).map(|(base_ty, members)| (base_ty, len * members))
}
fn check_struct(ty: Type) -> Option<(Type, u64)> {
let str_tys = ty.field_types();
if str_tys.len() == 0 {
return None
}
let mut prev_base_ty = None;
let mut members = 0;
for opt_homog_agg in str_tys.iter().map(|t| is_homogenous_aggregate_ty(*t)) {
match (prev_base_ty, opt_homog_agg) {
(_, None) => return None,
(None, Some((field_ty, field_members))) => {
prev_base_ty = Some(field_ty);
members = field_members;
},
(Some(prev_ty), Some((field_ty, field_members))) => {
if prev_ty != field_ty {
return None;
}
members += field_members;
}
}
}
let (base_ty, members) = (prev_base_ty.unwrap(), members);
if ty_size(ty) == ty_size(base_ty) * (members as usize) {
Some((base_ty, members))
} else {
None
}
}
let homog_agg = match ty.kind() {
Float => Some((ty, 1)),
Double => Some((ty, 1)),
Array => check_array(ty),
Struct => check_struct(ty),
_ => None
};
homog_agg.and_then(|(base_ty, members)| {
if members > 0 && members <= 8 {
Some((base_ty, members))
} else {
None
}
})
}
fn classify_ret_ty(ccx: &CrateContext, ret: &mut ArgType) {
if is_reg_ty(ret.ty) {
ret.extend_integer_width_to(64);
return;
}
ret.make_indirect(ccx);
if let Some((base_ty, members)) = is_homogenous_aggregate_ty(ret.ty) {
ret.cast = Some(Type::array(&base_ty, members));
return;
}
let size = ty_size(ret.ty);
if size <= 16 {
let llty = if size <= 1 {
Type::i8(ccx)
} else if size <= 2 {
Type::i16(ccx)
} else if size <= 4 {
Type::i32(ccx)
} else if size <= 8 {
Type::i64(ccx)
} else {
Type::array(&Type::i64(ccx), ((size + 7 ) / 8 ) as u64)
};
ret.cast = Some(llty);
return;
}
}
fn classify_arg_ty(ccx: &CrateContext, arg: &mut ArgType) {
if is_reg_ty(arg.ty) {
arg.extend_integer_width_to(64);
return;
}
if let Some((base_ty, members)) = is_homogenous_aggregate_ty(arg.ty) {
arg.cast = Some(Type::array(&base_ty, members));
return;
}
arg.cast = Some(struct_ty(ccx, arg.ty));
}
fn is_reg_ty(ty: Type) -> bool {
match ty.kind() {
Integer
| Pointer
| Float
| Double => true,
_ => false
}
}
fn coerce_to_long(ccx: &CrateContext, size: usize) -> Vec<Type> {
let long_ty = Type::i64(ccx);
let mut args = Vec::new();
let mut n = size / 64;
while n > 0 {
args.push(long_ty);
n -= 1;
}
let r = size % 64;
if r > 0 {
args.push(Type::ix(ccx, r as u64));
}
args
}
fn struct_ty(ccx: &CrateContext, ty: Type) -> Type {
let size = ty_size(ty) * 8;
Type::struct_(ccx, &coerce_to_long(ccx, size), false)
}
pub fn compute_abi_info(ccx: &CrateContext, fty: &mut FnType) {
if !fty.ret.is_ignore() {
classify_ret_ty(ccx, &mut fty.ret);
}
for arg in &mut fty.args {
if arg.is_ignore() { continue; }
classify_arg_ty(ccx, arg);
}
}