clang/test/SemaCXX/vector-size-conditional.cpp

   1 // RUN: %clang_cc1 -triple x86_64-linux-pc -fsyntax-only -verify -fexceptions -fcxx-exceptions %s -std=c++17
   2 // Note that this test depends on the size of long-long to be different from
   3 // int, so it specifies a triple.
   4
   5 using FourShorts = short __attribute__((__vector_size__(8)));
   6 using TwoInts = int __attribute__((__vector_size__(8)));
   7 using TwoUInts = unsigned __attribute__((__vector_size__(8)));
   8 using FourInts = int __attribute__((__vector_size__(16)));
   9 using FourUInts = unsigned __attribute__((__vector_size__(16)));
  10 using TwoLongLong = long long __attribute__((__vector_size__(16)));
  11 using FourLongLong = long long __attribute__((__vector_size__(32)));
  12 using TwoFloats = float __attribute__((__vector_size__(8)));
  13 using FourFloats = float __attribute__((__vector_size__(16)));
  14 using TwoDoubles = double __attribute__((__vector_size__(16)));
  15 using FourDoubles = double __attribute__((__vector_size__(32)));
  16
  17 FourShorts four_shorts;
  18 TwoInts two_ints;
  19 TwoUInts two_uints;
  20 FourInts four_ints;
  21 FourUInts four_uints;
  22 TwoLongLong two_ll;
  23 FourLongLong four_ll;
  24 TwoFloats two_floats;
  25 FourFloats four_floats;
  26 TwoDoubles two_doubles;
  27 FourDoubles four_doubles;
  28
  29 enum E {};
  30 enum class SE {};
  31 E e;
  32 SE se;
  33
  34 // Check the rules of the condition of the conditional operator.
  35 void Condition() {
  36   // Only int types are allowed here, the rest should fail to convert to bool.
  37   (void)(four_floats ? 1 : 1); // expected-error {{is not contextually convertible to 'bool'}}}
  38   (void)(two_doubles ? 1 : 1); // expected-error {{is not contextually convertible to 'bool'}}}
  39 }
  40
  41 // Check the rules of the LHS/RHS of the conditional operator.
  42 void Operands() {
  43   (void)(four_ints ? four_ints : throw 1); // expected-error {{GNU vector conditional operand cannot be a throw expression}}
  44   (void)(four_ints ? throw 1 : four_ints); // expected-error {{GNU vector conditional operand cannot be a throw expression}}
  45   (void)(four_ints ?: throw 1);            // expected-error {{GNU vector conditional operand cannot be a throw expression}}
  46   (void)(four_ints ? (void)1 : four_ints); // expected-error {{GNU vector conditional operand cannot be void}}
  47   (void)(four_ints ?: (void)1);            // expected-error {{GNU vector conditional operand cannot be void}}
  48
  49   // Vector types must be the same element size as the condition.
  50   (void)(four_ints ? two_ll : two_ll);             // expected-error {{vector condition type 'FourInts' (vector of 4 'int' values) and result type 'TwoLongLong' (vector of 2 'long long' values) do not have the same number of elements}}
  51   (void)(four_ints ? four_ll : four_ll);           // expected-error {{vector condition type 'FourInts' (vector of 4 'int' values) and result type 'FourLongLong' (vector of 4 'long long' values) do not have elements of the same size}}
  52   (void)(four_ints ? two_doubles : two_doubles);   // expected-error {{vector condition type 'FourInts' (vector of 4 'int' values) and result type 'TwoDoubles' (vector of 2 'double' values) do not have the same number of elements}}
  53   (void)(four_ints ? four_doubles : four_doubles); // expected-error {{vector condition type 'FourInts' (vector of 4 'int' values) and result type 'FourDoubles' (vector of 4 'double' values) do not have elements of the same size}}
  54   (void)(four_ints ?: two_ints);                   // expected-error {{vector operands to the vector conditional must be the same type ('FourInts' (vector of 4 'int' values) and 'TwoInts' (vector of 2 'int' values)}}
  55   (void)(four_ints ?: four_doubles);               // expected-error {{vector operands to the vector conditional must be the same type ('FourInts' (vector of 4 'int' values) and 'FourDoubles' (vector of 4 'double' values)}}
  56
  57   // Scalars are promoted, but must be the same element size.
  58   (void)(four_ints ? 3.0f : 3.0); // expected-error {{vector condition type 'FourInts' (vector of 4 'int' values) and result type '__attribute__((__vector_size__(4 * sizeof(double)))) double' (vector of 4 'double' values) do not have elements of the same size}}
  59   (void)(four_ints ? 5ll : 5);    // expected-error {{vector condition type 'FourInts' (vector of 4 'int' values) and result type '__attribute__((__vector_size__(4 * sizeof(long long)))) long long' (vector of 4 'long long' values) do not have elements of the same size}}
  60   (void)(four_ints ?: 3.0);       // expected-error {{cannot convert between scalar type 'double' and vector type 'FourInts' (vector of 4 'int' values) as implicit conversion would cause truncation}}
  61   (void)(four_ints ?: 5ll);       // We allow this despite GCc not allowing this since we support integral->vector-integral conversions despite integer rank.
  62
  63   // This one would be allowed in GCC, but we don't allow vectors of enum. Also,
  64   // the error message isn't perfect, since it is only going to be a problem
  65   // when both sides are an enum, otherwise it'll be promoted to whatever type
  66   // the other side causes.
  67   (void)(four_ints ? e : e);                          // expected-error {{enumeration type 'E' is not allowed in a vector conditional}}
  68   (void)(four_ints ? se : se);                        // expected-error {{enumeration type 'SE' is not allowed in a vector conditional}}
  69   (void)(four_shorts ? (short)5 : (unsigned short)5); // expected-error {{vector condition type 'FourShorts' (vector of 4 'short' values) and result type '__attribute__((__vector_size__(4 * sizeof(int)))) int' (vector of 4 'int' values) do not have elements of the same size}}
  70
  71   // They must also be convertible.
  72   (void)(four_ints ? 3.0f : 5u);
  73   (void)(four_ints ? 3.0f : 5);
  74   unsigned us = 5u;
  75   int sint = 5;
  76   short shrt = 5;
  77   unsigned short uss = 5u;
  78   // The following 2 error in GCC for truncation errors, but it seems
  79   // unimportant and inconsistent to enforce that rule.
  80   (void)(four_ints ? 3.0f : us);
  81   (void)(four_ints ? 3.0f : sint);
  82
  83   // Test promotion:
  84   (void)(four_shorts ? uss : shrt);  // expected-error {{vector condition type 'FourShorts' (vector of 4 'short' values) and result type '__attribute__((__vector_size__(4 * sizeof(int)))) int' (vector of 4 'int' values) do not have elements of the same size}}
  85   (void)(four_shorts ? shrt : shrt); // should be fine.
  86   (void)(four_ints ? uss : shrt);    // should be fine, since they get promoted to int.
  87   (void)(four_ints ? shrt : shrt);   //expected-error {{vector condition type 'FourInts' (vector of 4 'int' values) and result type '__attribute__((__vector_size__(4 * sizeof(short)))) short' (vector of 4 'short' values) do not have elements of the same size}}
  88
  89   // Vectors must be the same type as eachother.
  90   (void)(four_ints ? four_uints : four_floats); // expected-error {{vector operands to the vector conditional must be the same type ('FourUInts' (vector of 4 'unsigned int' values) and 'FourFloats' (vector of 4 'float' values))}}
  91   (void)(four_ints ? four_uints : four_ints);   // expected-error {{vector operands to the vector conditional must be the same type ('FourUInts' (vector of 4 'unsigned int' values) and 'FourInts' (vector of 4 'int' values))}}
  92   (void)(four_ints ? four_ints : four_uints);   // expected-error {{vector operands to the vector conditional must be the same type ('FourInts' (vector of 4 'int' values) and 'FourUInts' (vector of 4 'unsigned int' values))}}
  93
  94   // GCC rejects these, but our lax vector conversions don't seem to have a problem with them. Allow conversion of the float to an int as an extension.
  95   (void)(four_ints ? four_uints : 3.0f);
  96   (void)(four_ints ? four_ints : 3.0f);
  97
  98   // When there is a vector and a scalar, conversions must be legal.
  99   (void)(four_ints ? four_floats : 3); // should work, ints can convert to floats.
 100   (void)(four_ints ? four_uints : e);  // expected-error {{cannot convert between scalar type 'E' and vector type 'FourUInts'}}
 101   (void)(four_ints ? four_uints : se); // expected-error {{cannot convert between vector and non-scalar values ('FourUInts' (vector of 4 'unsigned int' values) and 'SE'}}
 102   // GCC permits this, but our conversion rules reject this for truncation.
 103   (void)(two_ints ? two_ints : us);        // expected-error {{cannot convert between scalar type 'unsigned int' and vector type 'TwoInts'}}
 104   (void)(four_shorts ? four_shorts : uss); // expected-error {{cannot convert between scalar type 'unsigned short' and vector type 'FourShorts'}}
 105   (void)(four_ints ? four_floats : us);    // expected-error {{cannot convert between scalar type 'unsigned int' and vector type 'FourFloats'}}
 106   (void)(four_ints ? four_floats : sint);  // expected-error {{cannot convert between scalar type 'int' and vector type 'FourFloats'}}
 107 }
 108
 109 template <typename T1, typename T2>
 110 struct is_same {
 111   static constexpr bool value = false;
 112 };
 113 template <typename T>
 114 struct is_same<T, T> {
 115   static constexpr bool value = true;
 116 };
 117 template <typename T1, typename T2>
 118 constexpr bool is_same_v = is_same<T1, T2>::value;
 119 template <typename T>
 120 T &&declval();
 121
 122 // Check the result types when given two vector types.
 123 void ResultTypes() {
 124   // Vectors must be the same, but result is the type of the LHS/RHS.
 125   static_assert(is_same_v<TwoInts, decltype(declval<TwoInts>() ? declval<TwoInts>() : declval<TwoInts>())>);
 126   static_assert(is_same_v<TwoFloats, decltype(declval<TwoInts>() ? declval<TwoFloats>() : declval<TwoFloats>())>);
 127
 128   // When both are scalars, converts to vectors of common type.
 129   static_assert(is_same_v<TwoUInts, decltype(declval<TwoInts>() ? declval<int>() : declval<unsigned int>())>);
 130
 131   // Constant is allowed since it doesn't truncate, and should promote to float.
 132   static_assert(is_same_v<TwoFloats, decltype(declval<TwoInts>() ? declval<float>() : 5u)>);
 133   static_assert(is_same_v<TwoFloats, decltype(declval<TwoInts>() ? 5 : declval<float>())>);
 134
 135   // when only 1 is a scalar, it should convert to a compatible type.
 136   static_assert(is_same_v<TwoFloats, decltype(declval<TwoInts>() ? declval<TwoFloats>() : declval<float>())>);
 137   static_assert(is_same_v<TwoInts, decltype(declval<TwoInts>() ? declval<TwoInts>() : declval<int>())>);
 138   static_assert(is_same_v<TwoFloats, decltype(declval<TwoInts>() ? declval<TwoFloats>() : 5)>);
 139
 140   // For the Binary conditional operator, the result type is either the vector on the RHS (that fits the rules on size/count), or the scalar extended to the correct count.
 141   static_assert(is_same_v<TwoInts, decltype(declval<TwoInts>() ?: declval<TwoInts>())>);
 142   static_assert(is_same_v<TwoInts, decltype(declval<TwoInts>() ?: declval<int>())>);
 143 }
 144
 145 template <typename Cond>
 146 void dependent_cond(Cond C) {
 147   (void)(C ? 1 : 2);
 148 }
 149
 150 template <typename Operand>
 151 void dependent_operand(Operand C) {
 152   (void)(two_ints ? 1 : C);
 153   (void)(two_ints ? C : 1);
 154   (void)(two_ints ? C : C);
 155 }
 156
 157 template <typename Cond, typename LHS, typename RHS>
 158 void all_dependent(Cond C, LHS L, RHS R) {
 159   (void)(C ? L : R);
 160 }
 161
 162 // Check dependent cases.
 163 void Templates() {
 164   dependent_cond(two_ints);
 165   dependent_operand(two_floats);
 166   // expected-error@159 {{vector operands to the vector conditional must be the same type ('__attribute__((__vector_size__(4 * sizeof(unsigned int)))) unsigned int' (vector of 4 'unsigned int' values) and '__attribute__((__vector_size__(4 * sizeof(double)))) double' (vector of 4 'double' values))}}}
 167   all_dependent(four_ints, four_uints, four_doubles); // expected-note {{in instantiation of}}
 168
 169   // expected-error@159 {{vector operands to the vector conditional must be the same type ('__attribute__((__vector_size__(4 * sizeof(unsigned int)))) unsigned int' (vector of 4 'unsigned int' values) and '__attribute__((__vector_size__(2 * sizeof(unsigned int)))) unsigned int' (vector of 2 'unsigned int' values))}}}
 170   all_dependent(four_ints, four_uints, two_uints); // expected-note {{in instantiation of}}
 171   all_dependent(four_ints, four_uints, four_uints);
 172 }