llvm-project/clang/test/CodeGenCXX/microsoft-abi-cdecl-method-sret.cpp
Reid Kleckner 677539d0af MS ABI: Fix __fastcall methods that return structs
The sret paramater consumes the register after the implicit 'this'
parameter, as with other calling conventions.

Fixes PR20278, which turned out to be very easy.

llvm-svn: 212669
2014-07-10 01:58:55 +00:00

45 lines
1.3 KiB
C++

// RUN: %clang_cc1 -triple i386-pc-win32 -emit-llvm %s -o - | FileCheck %s
// PR15768
// A trivial 12 byte struct is returned indirectly.
struct S {
S();
int a, b, c;
};
struct C {
S variadic_sret(const char *f, ...);
S __cdecl cdecl_sret();
S __cdecl byval_and_sret(S a);
int c;
};
S C::variadic_sret(const char *f, ...) { return S(); }
S C::cdecl_sret() { return S(); }
S C::byval_and_sret(S a) { return S(); }
// CHECK: define void @"\01?variadic_sret@C@@QAA?AUS@@PBDZZ"(%struct.C* %this, %struct.S* noalias sret %agg.result, i8* %f, ...)
// CHECK: define void @"\01?cdecl_sret@C@@QAA?AUS@@XZ"(%struct.C* %this, %struct.S* noalias sret %agg.result)
// CHECK: define void @"\01?byval_and_sret@C@@QAA?AUS@@U2@@Z"(%struct.C* %this, %struct.S* noalias sret %agg.result, %struct.S* byval align 4 %a)
int main() {
C c;
c.variadic_sret("asdf");
c.cdecl_sret();
c.byval_and_sret(S());
}
// CHECK-LABEL: define i32 @main()
// CHECK: call void {{.*}} @"\01?variadic_sret@C@@QAA?AUS@@PBDZZ"
// CHECK: call void @"\01?cdecl_sret@C@@QAA?AUS@@XZ"
// CHECK: call void @"\01?byval_and_sret@C@@QAA?AUS@@U2@@Z"
// __fastcall has similar issues.
struct A {
S __fastcall f(int x);
};
S A::f(int x) {
return S();
}
// CHECK-LABEL: define x86_fastcallcc void @"\01?f@A@@QAI?AUS@@H@Z"(%struct.A* inreg %this, %struct.S* inreg noalias sret %agg.result, i32 %x)