src/test/codegen/return-value-in-reg.rs

   1 //! This test checks that types of up to 128 bits are returned by-value instead of via out-pointer.
   2
   3 // compile-flags: -C no-prepopulate-passes -O
   4 // only-x86_64
   5
   6 #![crate_type = "lib"]
   7
   8 pub struct S {
   9     a: u64,
  10     b: u32,
  11     c: u32,
  12 }
  13
  14 // CHECK: define i128 @modify(%S* noalias nocapture dereferenceable(16) %s)
  15 #[no_mangle]
  16 pub fn modify(s: S) -> S {
  17     S { a: s.a + s.a, b: s.b + s.b, c: s.c + s.c }
  18 }
  19
  20 #[repr(packed)]
  21 pub struct TooBig {
  22     a: u64,
  23     b: u32,
  24     c: u32,
  25     d: u8,
  26 }
  27
  28 // CHECK: define void @m_big(%TooBig* [[ATTRS:.*sret.*]], %TooBig* [[ATTRS2:.*]] %s)
  29 #[no_mangle]
  30 pub fn m_big(s: TooBig) -> TooBig {
  31     TooBig { a: s.a + s.a, b: s.b + s.b, c: s.c + s.c, d: s.d + s.d }
  32 }