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 using EightBools = bool __attribute__((ext_vector_type(8)));
  17
  18 FourShorts four_shorts;
  19 TwoInts two_ints;
  20 TwoUInts two_uints;
  21 FourInts four_ints;
  22 FourUInts four_uints;
  23 TwoLongLong two_ll;
  24 FourLongLong four_ll;
  25 TwoFloats two_floats;
  26 FourFloats four_floats;
  27 TwoDoubles two_doubles;
  28 FourDoubles four_doubles;
  29 EightBools eight_bools;
  30 EightBools other_eight_bools;
  31
  32 enum E {};
  33 enum class SE {};
  34 E e;
  35 SE se;
  36
  37 // Check the rules of the condition of the conditional operator.
  38 void Condition() {
  39   // Only int types are allowed here, the rest should fail to convert to bool.
  40   (void)(four_floats ? 1 : 1); // expected-error {{is not contextually convertible to 'bool'}}}
  41   (void)(two_doubles ? 1 : 1); // expected-error {{is not contextually convertible to 'bool'}}}
  42 }
  43
  44 // Check the rules of the LHS/RHS of the conditional operator.
  45 void Operands() {
  46   (void)(four_ints ? four_ints : throw 1); // expected-error {{GNU vector conditional operand cannot be a throw expression}}
  47   (void)(four_ints ? throw 1 : four_ints); // expected-error {{GNU vector conditional operand cannot be a throw expression}}
  48   (void)(four_ints ?: throw 1);            // expected-error {{GNU vector conditional operand cannot be a throw expression}}
  49   (void)(four_ints ? (void)1 : four_ints); // expected-error {{GNU vector conditional operand cannot be void}}
  50   (void)(four_ints ?: (void)1);            // expected-error {{GNU vector conditional operand cannot be void}}
  51
  52   // Vector types must be the same element size as the condition.
  53   (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}}
  54   (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}}
  55   (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}}
  56   (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}}
  57   (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)}}
  58   (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)}}
  59
  60   // Scalars are promoted, but must be the same element size.
  61   (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}}
  62   (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}}
  63   (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}}
  64   (void)(four_ints ?: 5ll);       // We allow this despite GCc not allowing this since we support integral->vector-integral conversions despite integer rank.
  65
  66   // This one would be allowed in GCC, but we don't allow vectors of enum. Also,
  67   // the error message isn't perfect, since it is only going to be a problem
  68   // when both sides are an enum, otherwise it'll be promoted to whatever type
  69   // the other side causes.
  70   (void)(four_ints ? e : e);                          // expected-error {{enumeration type 'E' is not allowed in a vector conditional}}
  71   (void)(four_ints ? se : se);                        // expected-error {{enumeration type 'SE' is not allowed in a vector conditional}}
  72   (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}}
  73
  74   // They must also be convertible.
  75   (void)(four_ints ? 3.0f : 5u);
  76   (void)(four_ints ? 3.0f : 5);
  77   unsigned us = 5u;
  78   int sint = 5;
  79   short shrt = 5;
  80   unsigned short uss = 5u;
  81   // The following 2 error in GCC for truncation errors, but it seems
  82   // unimportant and inconsistent to enforce that rule.
  83   (void)(four_ints ? 3.0f : us);
  84   (void)(four_ints ? 3.0f : sint);
  85
  86   // Test promotion:
  87   (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}}
  88   (void)(four_shorts ? shrt : shrt); // should be fine.
  89   (void)(four_ints ? uss : shrt);    // should be fine, since they get promoted to int.
  90   (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}}
  91
  92   // Vectors must be the same type as each other.
  93   (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))}}
  94   (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))}}
  95   (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))}}
  96
  97   // 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.
  98   (void)(four_ints ? four_uints : 3.0f);
  99   (void)(four_ints ? four_ints : 3.0f);
 100
 101   // Allow conditional select on bool vectors.
 102   (void)(eight_bools ? eight_bools : other_eight_bools);
 103
 104   // When there is a vector and a scalar, conversions must be legal.
 105   (void)(four_ints ? four_floats : 3); // should work, ints can convert to floats.
 106   (void)(four_ints ? four_uints : e);  // expected-error {{cannot convert between scalar type 'E' and vector type 'FourUInts'}}
 107   (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'}}
 108   // GCC permits this, but our conversion rules reject this for truncation.
 109   (void)(two_ints ? two_ints : us);        // expected-error {{cannot convert between scalar type 'unsigned int' and vector type 'TwoInts'}}
 110   (void)(four_shorts ? four_shorts : uss); // expected-error {{cannot convert between scalar type 'unsigned short' and vector type 'FourShorts'}}
 111   (void)(four_ints ? four_floats : us);    // expected-error {{cannot convert between scalar type 'unsigned int' and vector type 'FourFloats'}}
 112   (void)(four_ints ? four_floats : sint);  // expected-error {{cannot convert between scalar type 'int' and vector type 'FourFloats'}}
 113 }
 114
 115 template <typename T1, typename T2>
 116 struct is_same {
 117   static constexpr bool value = false;
 118 };
 119 template <typename T>
 120 struct is_same<T, T> {
 121   static constexpr bool value = true;
 122 };
 123 template <typename T1, typename T2>
 124 constexpr bool is_same_v = is_same<T1, T2>::value;
 125 template <typename T>
 126 T &&declval();
 127
 128 // Check the result types when given two vector types.
 129 void ResultTypes() {
 130   // Vectors must be the same, but result is the type of the LHS/RHS.
 131   static_assert(is_same_v<TwoInts, decltype(declval<TwoInts>() ? declval<TwoInts>() : declval<TwoInts>())>);
 132   static_assert(is_same_v<TwoFloats, decltype(declval<TwoInts>() ? declval<TwoFloats>() : declval<TwoFloats>())>);
 133
 134   // When both are scalars, converts to vectors of common type.
 135   static_assert(is_same_v<TwoUInts, decltype(declval<TwoInts>() ? declval<int>() : declval<unsigned int>())>);
 136
 137   // Constant is allowed since it doesn't truncate, and should promote to float.
 138   static_assert(is_same_v<TwoFloats, decltype(declval<TwoInts>() ? declval<float>() : 5u)>);
 139   static_assert(is_same_v<TwoFloats, decltype(declval<TwoInts>() ? 5 : declval<float>())>);
 140
 141   // when only 1 is a scalar, it should convert to a compatible type.
 142   static_assert(is_same_v<TwoFloats, decltype(declval<TwoInts>() ? declval<TwoFloats>() : declval<float>())>);
 143   static_assert(is_same_v<TwoInts, decltype(declval<TwoInts>() ? declval<TwoInts>() : declval<int>())>);
 144   static_assert(is_same_v<TwoFloats, decltype(declval<TwoInts>() ? declval<TwoFloats>() : 5)>);
 145
 146   // 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.
 147   static_assert(is_same_v<TwoInts, decltype(declval<TwoInts>() ?: declval<TwoInts>())>);
 148   static_assert(is_same_v<TwoInts, decltype(declval<TwoInts>() ?: declval<int>())>);
 149 }
 150
 151 template <typename Cond>
 152 void dependent_cond(Cond C) {
 153   (void)(C ? 1 : 2);
 154 }
 155
 156 template <typename Operand>
 157 void dependent_operand(Operand C) {
 158   (void)(two_ints ? 1 : C);
 159   (void)(two_ints ? C : 1);
 160   (void)(two_ints ? C : C);
 161 }
 162
 163 template <typename Cond, typename LHS, typename RHS>
 164 void all_dependent(Cond C, LHS L, RHS R) {
 165   (void)(C ? L : R);
 166 }
 167
 168 // Check dependent cases.
 169 void Templates() {
 170   dependent_cond(two_ints);
 171   dependent_operand(two_floats);
 172   // expected-error@165 {{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))}}}
 173   all_dependent(four_ints, four_uints, four_doubles); // expected-note {{in instantiation of}}
 174
 175   // expected-error@165 {{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))}}}
 176   all_dependent(four_ints, four_uints, two_uints); // expected-note {{in instantiation of}}
 177   all_dependent(four_ints, four_uints, four_uints);
 178 }