llvm-project/clang/test/Sema/builtin-assume.c

// RUN: %clang_cc1 -triple i386-mingw32 -fms-extensions -fsyntax-only -verify %s
// RUN: %clang_cc1 -triple x86_64-unknown-unknown -fsyntax-only -verify %s

int foo(int *a, int i) {
#ifdef _MSC_VER
  __assume(i != 4);
  __assume(++i > 2); //expected-warning {{the argument to '__assume' has side effects that will be discarded}}

  int test = sizeof(struct{char qq[(__assume(i != 5), 7)];});
#else
  __builtin_assume(i != 4);
  __builtin_assume(++i > 2); //expected-warning {{the argument to '__builtin_assume' has side effects that will be discarded}}

  int test = sizeof(struct{char qq[(__builtin_assume(i != 5), 7)];});
#endif
  return a[i];
}