1 files changed, 97 insertions, 0 deletions
diff --git a/compiler/rustc_target/src/abi/call/arm.rs b/compiler/rustc_target/src/abi/call/arm.rs
new file mode 100644
index 000000000..e66c2132b
--- /dev/null
+++ b/compiler/rustc_target/src/abi/call/arm.rs
@@ -0,0 +1,97 @@
+use crate::abi::call::{ArgAbi, Conv, FnAbi, Reg, RegKind, Uniform};
+use crate::abi::{HasDataLayout, TyAbiInterface};
+use crate::spec::HasTargetSpec;
+
+fn is_homogeneous_aggregate<'a, Ty, C>(cx: &C, arg: &mut ArgAbi<'a, Ty>) -> Option<Uniform>
+where
+    Ty: TyAbiInterface<'a, C> + Copy,
+    C: HasDataLayout,
+{
+    arg.layout.homogeneous_aggregate(cx).ok().and_then(|ha| ha.unit()).and_then(|unit| {
+        let size = arg.layout.size;
+
+        // Ensure we have at most four uniquely addressable members.
+        if size > unit.size.checked_mul(4, cx).unwrap() {
+            return None;
+        }
+
+        let valid_unit = match unit.kind {
+            RegKind::Integer => false,
+            RegKind::Float => true,
+            RegKind::Vector => size.bits() == 64 || size.bits() == 128,
+        };
+
+        valid_unit.then_some(Uniform { unit, total: size })
+    })
+}
+
+fn classify_ret<'a, Ty, C>(cx: &C, ret: &mut ArgAbi<'a, Ty>, vfp: bool)
+where
+    Ty: TyAbiInterface<'a, C> + Copy,
+    C: HasDataLayout,
+{
+    if !ret.layout.is_aggregate() {
+        ret.extend_integer_width_to(32);
+        return;
+    }
+
+    if vfp {
+        if let Some(uniform) = is_homogeneous_aggregate(cx, ret) {
+            ret.cast_to(uniform);
+            return;
+        }
+    }
+
+    let size = ret.layout.size;
+    let bits = size.bits();
+    if bits <= 32 {
+        ret.cast_to(Uniform { unit: Reg::i32(), total: size });
+        return;
+    }
+    ret.make_indirect();
+}
+
+fn classify_arg<'a, Ty, C>(cx: &C, arg: &mut ArgAbi<'a, Ty>, vfp: bool)
+where
+    Ty: TyAbiInterface<'a, C> + Copy,
+    C: HasDataLayout,
+{
+    if !arg.layout.is_aggregate() {
+        arg.extend_integer_width_to(32);
+        return;
+    }
+
+    if vfp {
+        if let Some(uniform) = is_homogeneous_aggregate(cx, arg) {
+            arg.cast_to(uniform);
+            return;
+        }
+    }
+
+    let align = arg.layout.align.abi.bytes();
+    let total = arg.layout.size;
+    arg.cast_to(Uniform { unit: if align <= 4 { Reg::i32() } else { Reg::i64() }, total });
+}
+
+pub fn compute_abi_info<'a, Ty, C>(cx: &C, fn_abi: &mut FnAbi<'a, Ty>)
+where
+    Ty: TyAbiInterface<'a, C> + Copy,
+    C: HasDataLayout + HasTargetSpec,
+{
+    // If this is a target with a hard-float ABI, and the function is not explicitly
+    // `extern "aapcs"`, then we must use the VFP registers for homogeneous aggregates.
+    let vfp = cx.target_spec().llvm_target.ends_with("hf")
+        && fn_abi.conv != Conv::ArmAapcs
+        && !fn_abi.c_variadic;
+
+    if !fn_abi.ret.is_ignore() {
+        classify_ret(cx, &mut fn_abi.ret, vfp);
+    }
+
+    for arg in &mut fn_abi.args {
+        if arg.is_ignore() {
+            continue;
+        }
+        classify_arg(cx, arg, vfp);
+    }
+}