compiler/rustc_target/src/abi/call/s390x.rs

   1 // FIXME: The assumes we're using the non-vector ABI, i.e., compiling
   2 // for a pre-z13 machine or using -mno-vx.
   3
   4 use crate::abi::call::{ArgAbi, FnAbi, Reg};
   5 use crate::abi::{self, HasDataLayout, LayoutOf, TyAndLayout, TyAndLayoutMethods};
   6
   7 fn classify_ret<Ty>(ret: &mut ArgAbi<'_, Ty>) {
   8     if !ret.layout.is_aggregate() && ret.layout.size.bits() <= 64 {
   9         ret.extend_integer_width_to(64);
  10     } else {
  11         ret.make_indirect();
  12     }
  13 }
  14
  15 fn is_single_fp_element<'a, Ty, C>(cx: &C, layout: TyAndLayout<'a, Ty>) -> bool
  16 where
  17     Ty: TyAndLayoutMethods<'a, C>,
  18     C: LayoutOf<'a, Ty = Ty, TyAndLayout = TyAndLayout<'a, Ty>> + HasDataLayout,
  19 {
  20     match layout.abi {
  21         abi::Abi::Scalar(ref scalar) => scalar.value.is_float(),
  22         abi::Abi::Aggregate { .. } => {
  23             if layout.fields.count() == 1 && layout.fields.offset(0).bytes() == 0 {
  24                 is_single_fp_element(cx, layout.field(cx, 0))
  25             } else {
  26                 false
  27             }
  28         }
  29         _ => false,
  30     }
  31 }
  32
  33 fn classify_arg<'a, Ty, C>(cx: &C, arg: &mut ArgAbi<'a, Ty>)
  34 where
  35     Ty: TyAndLayoutMethods<'a, C> + Copy,
  36     C: LayoutOf<'a, Ty = Ty, TyAndLayout = TyAndLayout<'a, Ty>> + HasDataLayout,
  37 {
  38     if !arg.layout.is_aggregate() && arg.layout.size.bits() <= 64 {
  39         arg.extend_integer_width_to(64);
  40         return;
  41     }
  42
  43     if is_single_fp_element(cx, arg.layout) {
  44         match arg.layout.size.bytes() {
  45             4 => arg.cast_to(Reg::f32()),
  46             8 => arg.cast_to(Reg::f64()),
  47             _ => arg.make_indirect(),
  48         }
  49     } else {
  50         match arg.layout.size.bytes() {
  51             1 => arg.cast_to(Reg::i8()),
  52             2 => arg.cast_to(Reg::i16()),
  53             4 => arg.cast_to(Reg::i32()),
  54             8 => arg.cast_to(Reg::i64()),
  55             _ => arg.make_indirect(),
  56         }
  57     }
  58 }
  59
  60 pub fn compute_abi_info<'a, Ty, C>(cx: &C, fn_abi: &mut FnAbi<'a, Ty>)
  61 where
  62     Ty: TyAndLayoutMethods<'a, C> + Copy,
  63     C: LayoutOf<'a, Ty = Ty, TyAndLayout = TyAndLayout<'a, Ty>> + HasDataLayout,
  64 {
  65     if !fn_abi.ret.is_ignore() {
  66         classify_ret(&mut fn_abi.ret);
  67     }
  68
  69     for arg in &mut fn_abi.args {
  70         if arg.is_ignore() {
  71             continue;
  72         }
  73         classify_arg(cx, arg);
  74     }
  75 }