rustc_target/callconv/
s390x.rs

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1// Reference: ELF Application Binary Interface s390x Supplement
2// https://github.com/IBM/s390x-abi
3
4use rustc_abi::{BackendRepr, HasDataLayout, TyAbiInterface};
5
6use crate::callconv::{ArgAbi, FnAbi, Reg, RegKind};
7use crate::spec::HasTargetSpec;
8
9fn classify_ret<Ty>(ret: &mut ArgAbi<'_, Ty>) {
10    let size = ret.layout.size;
11    if size.bits() <= 128 && matches!(ret.layout.backend_repr, BackendRepr::Vector { .. }) {
12        return;
13    }
14    if !ret.layout.is_aggregate() && size.bits() <= 64 {
15        ret.extend_integer_width_to(64);
16    } else {
17        ret.make_indirect();
18    }
19}
20
21fn classify_arg<'a, Ty, C>(cx: &C, arg: &mut ArgAbi<'a, Ty>)
22where
23    Ty: TyAbiInterface<'a, C> + Copy,
24    C: HasDataLayout + HasTargetSpec,
25{
26    if !arg.layout.is_sized() {
27        // Not touching this...
28        return;
29    }
30    if arg.is_ignore() {
31        // s390x-unknown-linux-{gnu,musl,uclibc} doesn't ignore ZSTs.
32        if cx.target_spec().os == "linux"
33            && matches!(&*cx.target_spec().env, "gnu" | "musl" | "uclibc")
34            && arg.layout.is_zst()
35        {
36            arg.make_indirect_from_ignore();
37        }
38        return;
39    }
40
41    let size = arg.layout.size;
42    if size.bits() <= 128 {
43        if let BackendRepr::Vector { .. } = arg.layout.backend_repr {
44            // pass non-wrapped vector types using `PassMode::Direct`
45            return;
46        }
47
48        if arg.layout.is_single_vector_element(cx, size) {
49            // pass non-transparant wrappers around a vector as `PassMode::Cast`
50            arg.cast_to(Reg { kind: RegKind::Vector, size });
51            return;
52        }
53    }
54    if !arg.layout.is_aggregate() && size.bits() <= 64 {
55        arg.extend_integer_width_to(64);
56        return;
57    }
58
59    if arg.layout.is_single_fp_element(cx) {
60        match size.bytes() {
61            4 => arg.cast_to(Reg::f32()),
62            8 => arg.cast_to(Reg::f64()),
63            _ => arg.make_indirect(),
64        }
65    } else {
66        match size.bytes() {
67            1 => arg.cast_to(Reg::i8()),
68            2 => arg.cast_to(Reg::i16()),
69            4 => arg.cast_to(Reg::i32()),
70            8 => arg.cast_to(Reg::i64()),
71            _ => arg.make_indirect(),
72        }
73    }
74}
75
76pub(crate) fn compute_abi_info<'a, Ty, C>(cx: &C, fn_abi: &mut FnAbi<'a, Ty>)
77where
78    Ty: TyAbiInterface<'a, C> + Copy,
79    C: HasDataLayout + HasTargetSpec,
80{
81    if !fn_abi.ret.is_ignore() {
82        classify_ret(&mut fn_abi.ret);
83    }
84
85    for arg in fn_abi.args.iter_mut() {
86        classify_arg(cx, arg);
87    }
88}
rustc_target/callconv/s390x.rs

rustc_target/callconv/
s390x.rs
