diff --git a/clang/test/SemaCXX/vector.cpp b/clang/test/SemaCXX/vector.cpp
--- a/clang/test/SemaCXX/vector.cpp
+++ b/clang/test/SemaCXX/vector.cpp
@@ -772,3 +772,193 @@
 }
 #endif
 }
+
+namespace vector_implicit_conversions {
+// Test ext_vector_type builtin operators in the presence of implicit conversions
+
+typedef int __attribute__((ext_vector_type(4))) vec4i;
+
+struct vec4i_wrapper {
+    vec4i x;
+
+    vec4i_wrapper(const vec4i& val): x(val) {}
+    operator vec4i() const { return x; } // expected-note 1+ {{candidate function}}
+};
+
+vec4i_wrapper operator| (const vec4i_wrapper& lhs, const vec4i_wrapper rhs) { return vec4i(lhs) | vec4i(rhs); }
+vec4i_wrapper& operator|= (vec4i_wrapper& lhs, const vec4i_wrapper& rhs) { return lhs = lhs | rhs; } // #oreq_operator
+
+vec4i_wrapper test_compound_assignment_mixed(vec4i_wrapper a, vec4i b) {
+  // These are not accepted because the LHS isn't subject to conversions, so no built-in operators apply here
+  a += b; // expected-error{{no viable overloaded '+='}}
+  a -= b; // expected-error{{no viable overloaded '-='}}
+  a *= b; // expected-error{{no viable overloaded '*='}}
+  a /= b; // expected-error{{no viable overloaded '/='}}
+  a %= b; // expected-error{{no viable overloaded '%='}}
+  a &= b; // expected-error{{no viable overloaded '&='}}
+  // Note: This operator is explicitly defined above, so it is accpted via implicit conversions
+  a |= b;
+  a ^= b; // expected-error{{no viable overloaded '^='}}
+  a >>= b; // expected-error{{no viable overloaded '>>='}}
+  a <<= b; // expected-error{{no viable overloaded '<<='}}
+
+  b += a;
+  b -= a;
+  b *= a;
+  b /= a;
+  // FIXME: Consistency for vector builtin operators with implicit conversions https://github.com/llvm/llvm-project/issues/62949
+  b %= a; // expected-error{{invalid operands to binary expression}}
+  b &= a; // expected-error{{invalid operands to binary expression}}
+  b |= a; // expected-error{{invalid operands to binary expression}}
+  // expected-note@#oreq_operator{{candidate function not viable}}
+  b ^= a; // expected-error{{invalid operands to binary expression}}
+  b >>= a; // expected-error{{used type 'vec4i_wrapper' where integer is required}}
+  b <<= a; // expected-error{{used type 'vec4i_wrapper' where integer is required}}
+
+  return a;
+}
+
+vec4i_wrapper test_operators_mixed(vec4i_wrapper a, vec4i b) {
+  // The operator overload isn't defined, so this is implicitly:
+  // a = vec4i_wrapper(vec4i(a) + b)
+  a = a + b;
+  a = b + a;
+  a = a - b;
+  a = b - a;
+  a = a * b;
+  a = b * a;
+  a = a / b;
+  a = b / a;
+  // FIXME: Consistency for vector builtin operators with implicit conversions https://github.com/llvm/llvm-project/issues/62949
+  a = a % b; // expected-error{{invalid operands to binary expression}}
+  a = b % a; // expected-error{{invalid operands to binary expression}}
+
+  // Conditionals yield vectors of integers
+  vec4i c;
+  c = a == b;
+  c = b == a;
+  c = a != b;
+  c = b != a;
+  c = a <= b;
+  c = b <= a;
+  c = a >= b;
+  c = b >= a;
+  c = a < b;
+  c = b < a;
+  c = a > b;
+  c = b > a;
+
+  a = a && b; // expected-error{{invalid operands to binary expression}}
+  // expected-error@-1{{cannot convert between vector and non-scalar values}}
+  a = b && a; // expected-error{{invalid operands to binary expression}}
+  // expected-error@-1{{cannot convert between vector and non-scalar values}}
+  a = a || b; // expected-error{{invalid operands to binary expression}}
+  // expected-error@-1{{cannot convert between vector and non-scalar values}}
+  a = b || a; // expected-error{{invalid operands to binary expression}}
+  // expected-error@-1{{cannot convert between vector and non-scalar values}}
+
+  a = a & b; // expected-error{{invalid operands to binary expression}}
+  a = b & a; // expected-error{{invalid operands to binary expression}}
+  // Note: These have a user-defined operator overload which is being selected
+  a = a | b;
+  a = b | a;
+  a = a ^ b; // expected-error{{invalid operands to binary expression}}
+  a = b ^ a; // expected-error{{invalid operands to binary expression}}
+  a = a << b; // expected-error{{used type 'vec4i_wrapper' where integer is required}}
+  a = b << a; // expected-error{{used type 'vec4i_wrapper' where integer is required}}
+  a = a >> b; // expected-error{{used type 'vec4i_wrapper' where integer is required}}
+  a = b >> a; // expected-error{{used type 'vec4i_wrapper' where integer is required}}
+
+  return a;
+}
+
+vec4i_wrapper test_operators_homogenous(vec4i_wrapper a, vec4i_wrapper b) {
+  // The operator overload isn't defined, so this is implicitly:
+  // a = vec4i_wrapper(vec4i(a) + vec4i(b))
+  a = a + b;
+  a = a - b;
+  a = a * b;
+  a = a / b;
+  // FIXME: Consistency for vector builtin operators with implicit conversions https://github.com/llvm/llvm-project/issues/62949
+  a = a % b; // expected-error{{invalid operands to binary expression}}
+
+  // Conditionals yield vectors of integers
+  vec4i c;
+  c = a == b;
+  c = a != b;
+  c = a <= b;
+  c = a >= b;
+  c = a < b;
+  c = a > b;
+
+  a = a && b; // expected-error{{invalid operands to binary expression}}
+  // expected-error@-1{{no viable conversion from 'vec4i_wrapper' to 'bool'}}
+  a = a || b; // expected-error{{invalid operands to binary expression}}
+  // expected-error@-1{{no viable conversion from 'vec4i_wrapper' to 'bool'}}
+
+  a = a & b; // expected-error{{invalid operands to binary expression}}
+  // Note: This has a user-defined operator overload which is being selected
+  a = a | b;
+  a = a ^ b; // expected-error{{invalid operands to binary expression}}
+  a = a << b; // expected-error{{invalid operands to binary expression}}
+  a = a >> b; // expected-error{{invalid operands to binary expression}}
+
+  return a;
+}
+
+vec4i_wrapper test_operators_with_scalar(vec4i_wrapper a, int b) {
+  // The operator overload isn't defined, so this is implicitly:
+  // a = vec4i_wrapper(vec4i(a) + b)
+  // And b is implictly splatted
+  // FIXME: Consistency for vector builtin operators with implicit conversions https://github.com/llvm/llvm-project/issues/62949
+  // FIXME: Provide vector/scalar builtin overloads https://github.com/llvm/llvm-project/issues/62869
+  a = a + b; // expected-error{{invalid operands to binary expression}}
+  a = b + a; // expected-error{{invalid operands to binary expression}}
+  a = a - b; // expected-error{{invalid operands to binary expression}}
+  a = b - a; // expected-error{{invalid operands to binary expression}}
+  a = a * b; // expected-error{{invalid operands to binary expression}}
+  a = b * a; // expected-error{{invalid operands to binary expression}}
+  a = a / b; // expected-error{{invalid operands to binary expression}}
+  a = b / a; // expected-error{{invalid operands to binary expression}}
+  a = a % b; // expected-error{{invalid operands to binary expression}}
+  a = b % a; // expected-error{{invalid operands to binary expression}}
+
+  // Conditionals yield vectors of integers
+  vec4i c;
+  c = a == b; // expected-error{{invalid operands to binary expression}}
+  c = b == a; // expected-error{{invalid operands to binary expression}}
+  c = a != b; // expected-error{{invalid operands to binary expression}}
+  c = b != a; // expected-error{{invalid operands to binary expression}}
+  c = a <= b; // expected-error{{invalid operands to binary expression}}
+  c = b <= a; // expected-error{{invalid operands to binary expression}}
+  c = a >= b; // expected-error{{invalid operands to binary expression}}
+  c = b >= a; // expected-error{{invalid operands to binary expression}}
+  c = a < b; // expected-error{{invalid operands to binary expression}}
+  c = b < a; // expected-error{{invalid operands to binary expression}}
+  c = a > b; // expected-error{{invalid operands to binary expression}}
+  c = b > a; // expected-error{{invalid operands to binary expression}}
+
+  a = a && b; // expected-error{{invalid operands to binary expression}}
+  // expected-error@-1{{no viable conversion from 'vec4i_wrapper' to 'bool'}}
+  a = b && a; // expected-error{{invalid operands to binary expression}}
+  // expected-error@-1{{no viable conversion from 'vec4i_wrapper' to 'bool'}}
+  a = a || b; // expected-error{{invalid operands to binary expression}}
+  // expected-error@-1{{no viable conversion from 'vec4i_wrapper' to 'bool'}}
+  a = b || a; // expected-error{{invalid operands to binary expression}}
+  // expected-error@-1{{no viable conversion from 'vec4i_wrapper' to 'bool'}}
+
+  a = a & b; // expected-error{{invalid operands to binary expression}}
+  a = b & a; // expected-error{{invalid operands to binary expression}}
+  // Note: These have a user-defined operator overload which is being selected
+  a = a | b;
+  a = b | a;
+  a = a ^ b; // expected-error{{invalid operands to binary expression}}
+  a = b ^ a; // expected-error{{invalid operands to binary expression}}
+  a = a << b; // expected-error{{invalid operands to binary expression}}
+  a = b << a; // expected-error{{invalid operands to binary expression}}
+  a = a >> b; // expected-error{{invalid operands to binary expression}}
+  a = b >> a; // expected-error{{invalid operands to binary expression}}
+
+  return a;
+}
+} // vector_implicit_conversions