1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 #![allow(non_upper_case_globals)]
13 use llvm::{Integer, Pointer, Float, Double, Struct, Array, Vector};
14 use abi::{self, FnType, ArgType};
15 use context::CrateContext;
18 fn ty_size(ty: Type) -> usize {
22 fn is_homogenous_aggregate_ty(ty: Type) -> Option<(Type, u64)> {
23 fn check_array(ty: Type) -> Option<(Type, u64)> {
24 let len = ty.array_length() as u64;
28 let elt = ty.element_type();
30 // if our element is an HFA/HVA, so are we; multiply members by our len
31 is_homogenous_aggregate_ty(elt).map(|(base_ty, members)| (base_ty, len * members))
34 fn check_struct(ty: Type) -> Option<(Type, u64)> {
35 let str_tys = ty.field_types();
36 if str_tys.len() == 0 {
40 let mut prev_base_ty = None;
42 for opt_homog_agg in str_tys.iter().map(|t| is_homogenous_aggregate_ty(*t)) {
43 match (prev_base_ty, opt_homog_agg) {
44 // field isn't itself an HFA, so we aren't either
45 (_, None) => return None,
47 // first field - store its type and number of members
48 (None, Some((field_ty, field_members))) => {
49 prev_base_ty = Some(field_ty);
50 members = field_members;
53 // 2nd or later field - give up if it's a different type; otherwise incr. members
54 (Some(prev_ty), Some((field_ty, field_members))) => {
55 if prev_ty != field_ty {
58 members += field_members;
63 // Because of previous checks, we know prev_base_ty is Some(...) because
64 // 1. str_tys has at least one element; and
65 // 2. prev_base_ty was filled in (or we would've returned early)
66 let (base_ty, members) = (prev_base_ty.unwrap(), members);
68 // Ensure there is no padding.
69 if ty_size(ty) == ty_size(base_ty) * (members as usize) {
70 Some((base_ty, members))
76 let homog_agg = match ty.kind() {
77 Float => Some((ty, 1)),
78 Double => Some((ty, 1)),
79 Array => check_array(ty),
80 Struct => check_struct(ty),
81 Vector => match ty_size(ty) {
88 // Ensure we have at most four uniquely addressable members
89 homog_agg.and_then(|(base_ty, members)| {
90 if members > 0 && members <= 4 {
91 Some((base_ty, members))
98 fn classify_ret_ty(ccx: &CrateContext, ret: &mut ArgType) {
99 if is_reg_ty(ret.ty) {
100 ret.extend_integer_width_to(32);
103 if let Some((base_ty, members)) = is_homogenous_aggregate_ty(ret.ty) {
104 ret.cast = Some(Type::array(&base_ty, members));
107 let size = ty_size(ret.ty);
109 let llty = if size <= 1 {
111 } else if size <= 2 {
113 } else if size <= 4 {
115 } else if size <= 8 {
118 Type::array(&Type::i64(ccx), ((size + 7 ) / 8 ) as u64)
120 ret.cast = Some(llty);
123 ret.make_indirect(ccx);
126 fn classify_arg_ty(ccx: &CrateContext, arg: &mut ArgType) {
127 if is_reg_ty(arg.ty) {
128 arg.extend_integer_width_to(32);
131 if let Some((base_ty, members)) = is_homogenous_aggregate_ty(arg.ty) {
132 arg.cast = Some(Type::array(&base_ty, members));
135 let size = ty_size(arg.ty);
137 let llty = if size == 0 {
138 Type::array(&Type::i64(ccx), 0)
139 } else if size == 1 {
141 } else if size == 2 {
143 } else if size <= 4 {
145 } else if size <= 8 {
148 Type::array(&Type::i64(ccx), ((size + 7 ) / 8 ) as u64)
150 arg.cast = Some(llty);
153 arg.make_indirect(ccx);
156 fn is_reg_ty(ty: Type) -> bool {
167 pub fn compute_abi_info(ccx: &CrateContext, fty: &mut FnType) {
168 if !fty.ret.is_ignore() {
169 classify_ret_ty(ccx, &mut fty.ret);
172 for arg in &mut fty.args {
173 if arg.is_ignore() { continue; }
174 classify_arg_ty(ccx, arg);