clang/test/CodeGenCXX/cxx2a-three-way-comparison.cpp

   1 // RUN: %clang_cc1 -std=c++2a -emit-llvm %s -o - -triple %itanium_abi_triple | FileCheck %s --check-prefixes=CHECK,ITANIUM
   2 // RUN: %clang_cc1 -std=c++2a -emit-llvm %s -o - -triple x86_64-pc-win32 2>&1 | FileCheck %s --check-prefixes=CHECK,MSABI
   3
   4 namespace std {
   5   struct strong_ordering {
   6     int n;
   7     constexpr operator int() const { return n; }
   8     static const strong_ordering less, equal, greater;
   9   };
  10   constexpr strong_ordering strong_ordering::less = {-1};
  11   constexpr strong_ordering strong_ordering::equal = {0};
  12   constexpr strong_ordering strong_ordering::greater = {1};
  13 }
  14
  15 struct Primary {
  16   virtual void f();
  17   std::strong_ordering operator<=>(const Primary&) const = default;
  18 };
  19 struct X {
  20   virtual struct Y &operator=(Y&&);
  21   virtual struct Y &operator=(const Y&);
  22   std::strong_ordering operator<=>(const X&) const = default;
  23 };
  24 // The vtable for Y should contain the following entries in order:
  25 //  - Primary::f
  26 //  - Y::operator<=>
  27 //  - Y::operator=(const Y&) (implicit)
  28 //  - Y::operator=(Y&&) (implicit)
  29 //  - Y::operator==(const Y&) const (implicit)
  30 // See:
  31 //   https://github.com/itanium-cxx-abi/cxx-abi/issues/83 for assignment operator
  32 //   https://github.com/itanium-cxx-abi/cxx-abi/issues/88 for equality comparison
  33 // FIXME: What rule does MSVC use?
  34 struct Y : Primary, X {
  35   virtual std::strong_ordering operator<=>(const Y&) const = default;
  36 };
  37 Y y;
  38 // ITANIUM: @_ZTV1Y = {{.*}}constant {{.*}} null, {{.*}} @_ZTI1Y, {{.*}} @_ZN7Primary1fEv, {{.*}} @_ZNK1YssERKS_, {{.*}} @_ZN1YaSERKS_, {{.*}} @_ZN1YaSEOS_, {{.*}} @_ZNK1YeqERKS_], {{.*}} -[[POINTERSIZE:4|8]]
  39 // ITANIUM-SAME: @_ZTI1Y, {{.*}} @_ZThn[[POINTERSIZE]]_N1YaSERKS_
  40
  41 struct A {
  42   void operator<=>(int);
  43 };
  44
  45 // ITANIUM: define {{.*}}@_ZN1AssEi(
  46 // MSABI: define {{.*}}@"??__MA@@QEAAXH@Z"(
  47 void A::operator<=>(int) {}
  48
  49 // ITANIUM: define {{.*}}@_Zssi1A(
  50 // MSABI: define {{.*}}@"??__M@YAXHUA@@@Z"(
  51 void operator<=>(int, A) {}
  52
  53 int operator<=>(A, A);
  54
  55 // ITANIUM: define {{.*}}_Z1f1A(
  56 // MSABI: define {{.*}}@"?f@@YAHUA@@@Z"(
  57 int f(A a) {
  58   // ITANIUM: %[[RET:.*]] = call {{.*}}_Zss1AS_(
  59   // ITANIUM: ret i32 %[[RET]]
  60   // MSABI: %[[RET:.*]] = call {{.*}}"??__M@YAHUA@@0@Z"(
  61   // MSABI: ret i32 %[[RET]]
  62   return a <=> a;
  63 }
  64
  65 // CHECK-LABEL: define {{.*}}builtin_cmp
  66 void builtin_cmp(int a) {
  67   // CHECK: icmp slt
  68   // CHECK: select
  69   // CHECK: icmp eq
  70   // CHECK: select
  71   a <=> a;
  72 }