rustc_target/callconv/
arm.rs

Help
1use rustc_abi::{HasDataLayout, TyAbiInterface};
2
3use crate::callconv::{ArgAbi, Conv, FnAbi, Reg, RegKind, Uniform};
4use crate::spec::HasTargetSpec;
5
6fn is_homogeneous_aggregate<'a, Ty, C>(cx: &C, arg: &mut ArgAbi<'a, Ty>) -> Option<Uniform>
7where
8    Ty: TyAbiInterface<'a, C> + Copy,
9    C: HasDataLayout,
10{
11    arg.layout.homogeneous_aggregate(cx).ok().and_then(|ha| ha.unit()).and_then(|unit| {
12        let size = arg.layout.size;
13
14        // Ensure we have at most four uniquely addressable members.
15        if size > unit.size.checked_mul(4, cx).unwrap() {
16            return None;
17        }
18
19        let valid_unit = match unit.kind {
20            RegKind::Integer => false,
21            RegKind::Float => true,
22            RegKind::Vector => size.bits() == 64 || size.bits() == 128,
23        };
24
25        valid_unit.then_some(Uniform::consecutive(unit, size))
26    })
27}
28
29fn classify_ret<'a, Ty, C>(cx: &C, ret: &mut ArgAbi<'a, Ty>, vfp: bool)
30where
31    Ty: TyAbiInterface<'a, C> + Copy,
32    C: HasDataLayout,
33{
34    if !ret.layout.is_sized() {
35        // Not touching this...
36        return;
37    }
38    if !ret.layout.is_aggregate() {
39        ret.extend_integer_width_to(32);
40        return;
41    }
42
43    if vfp {
44        if let Some(uniform) = is_homogeneous_aggregate(cx, ret) {
45            ret.cast_to(uniform);
46            return;
47        }
48    }
49
50    let size = ret.layout.size;
51    let bits = size.bits();
52    if bits <= 32 {
53        ret.cast_to(Uniform::new(Reg::i32(), size));
54        return;
55    }
56    ret.make_indirect();
57}
58
59fn classify_arg<'a, Ty, C>(cx: &C, arg: &mut ArgAbi<'a, Ty>, vfp: bool)
60where
61    Ty: TyAbiInterface<'a, C> + Copy,
62    C: HasDataLayout,
63{
64    if !arg.layout.is_sized() {
65        // Not touching this...
66        return;
67    }
68    if !arg.layout.is_aggregate() {
69        arg.extend_integer_width_to(32);
70        return;
71    }
72
73    if vfp {
74        if let Some(uniform) = is_homogeneous_aggregate(cx, arg) {
75            arg.cast_to(uniform);
76            return;
77        }
78    }
79
80    let align = arg.layout.align.abi.bytes();
81    let total = arg.layout.size;
82    arg.cast_to(Uniform::consecutive(if align <= 4 { Reg::i32() } else { Reg::i64() }, total));
83}
84
85pub(crate) fn compute_abi_info<'a, Ty, C>(cx: &C, fn_abi: &mut FnAbi<'a, Ty>)
86where
87    Ty: TyAbiInterface<'a, C> + Copy,
88    C: HasDataLayout + HasTargetSpec,
89{
90    // If this is a target with a hard-float ABI, and the function is not explicitly
91    // `extern "aapcs"`, then we must use the VFP registers for homogeneous aggregates.
92    let vfp = cx.target_spec().llvm_target.ends_with("hf")
93        && fn_abi.conv != Conv::ArmAapcs
94        && !fn_abi.c_variadic;
95
96    if !fn_abi.ret.is_ignore() {
97        classify_ret(cx, &mut fn_abi.ret, vfp);
98    }
99
100    for arg in fn_abi.args.iter_mut() {
101        if arg.is_ignore() {
102            continue;
103        }
104        classify_arg(cx, arg, vfp);
105    }
106}
rustc_target/callconv/arm.rs

rustc_target/callconv/
arm.rs
