llvm-project/clang/test/Parser/pragma-unroll.cpp

// RUN: %clang_cc1 -std=c++11 -verify %s

// Note that this puts the expected lines before the directives to work around
// limitations in the -verify mode.

void test(int *List, int Length) {
  int i = 0;

#pragma unroll
  while (i + 1 < Length) {
    List[i] = i;
  }

#pragma nounroll
  while (i < Length) {
    List[i] = i;
  }

#pragma unroll 4
  while (i - 1 < Length) {
    List[i] = i;
  }

#pragma unroll(8)
  while (i - 2 < Length) {
    List[i] = i;
  }

/* expected-error {{expected ')'}} */ #pragma unroll(4
/* expected-error {{missing argument; expected an integer value}} */ #pragma unroll()
/* expected-warning {{extra tokens at end of '#pragma unroll'}} */ #pragma unroll 1 2
  while (i-6 < Length) {
    List[i] = i;
  }

/* expected-warning {{extra tokens at end of '#pragma nounroll'}} */ #pragma nounroll 1
  while (i-7 < Length) {
    List[i] = i;
  }

/* expected-error {{expected ')'}} */ #pragma unroll(()
/* expected-error {{expected expression}} */ #pragma unroll -
/* The values of 0 and 1 block any unrolling of the loop. */ #pragma unroll 0
/* expected-error {{value '3000000000' is too large}} */ #pragma unroll(3000000000)
/* expected-error {{value '3000000000' is too large}} */ #pragma unroll 3000000000
  while (i-8 < Length) {
    List[i] = i;
  }

/* The values of 0 and 1 block any unrolling of the loop. */ #pragma unroll(0)
  while (i-8 < Length) {
    List[i] = i;
  }

#pragma unroll
/* expected-error {{expected a for, while, or do-while loop to follow '#pragma unroll'}} */ int j = Length;
#pragma unroll 4
/* expected-error {{expected a for, while, or do-while loop to follow '#pragma unroll'}} */ int k = Length;
#pragma nounroll
/* expected-error {{expected a for, while, or do-while loop to follow '#pragma nounroll'}} */ int l = Length;

  switch (i) {
  case 1:
#pragma unroll
/* expected-error {{expected a for, while, or do-while loop to follow '#pragma unroll'}} */ [[fallthrough]];
  case 2:
    for (int i = 0; i < 10; ++i);
    break;
  }

#pragma unroll 4
/* expected-error {{incompatible directives 'unroll(disable)' and '#pragma unroll(4)'}} */ #pragma clang loop unroll(disable)
  while (i-10 < Length) {
    List[i] = i;
  }

#pragma unroll(4)
/* expected-error {{incompatible directives 'unroll(full)' and '#pragma unroll(4)'}} */ #pragma clang loop unroll(full)
  while (i-11 < Length) {
    List[i] = i;
  }

#pragma unroll(4)
/* expected-error {{incompatible directives 'unroll(enable)' and '#pragma unroll(4)'}} */ #pragma clang loop unroll(enable)
  while (i-11 < Length) {
    List[i] = i;
  }

#pragma unroll(4)
/* expected-error {{incompatible directives '#pragma unroll' and '#pragma unroll(4)'}} */ #pragma unroll
  while (i-11 < Length) {
    List[i] = i;
  }

#pragma clang loop unroll_count(4)
/* expected-error {{incompatible directives '#pragma nounroll' and 'unroll_count(4)'}} */ #pragma nounroll
  while (i-12 < Length) {
    List[i] = i;
  }

#pragma nounroll
/* expected-error {{duplicate directives '#pragma nounroll' and '#pragma nounroll'}} */ #pragma nounroll
  while (i-13 < Length) {
    List[i] = i;
  }

#pragma unroll
/* expected-error {{duplicate directives '#pragma unroll' and '#pragma unroll'}} */ #pragma unroll
  while (i-14 < Length) {
    List[i] = i;
  }

#pragma unroll
/* expected-error {{duplicate directives '#pragma unroll' and 'unroll(full)'}} */ #pragma clang loop unroll(full)
  while (i-15 < Length) {
    List[i] = i;
  }

#pragma unroll 4
/* expected-error {{duplicate directives '#pragma unroll(4)' and '#pragma unroll(4)'}} */ #pragma unroll(4)
  while (i-16 < Length) {
    List[i] = i;
  }

#pragma unroll
/* expected-error {{expected statement}} */ }

using size_t = unsigned long long;

template <bool Flag>
int FailToBuild(int n) {
  constexpr int N = 100;
  auto init = [=]() { return Flag ? n : 0UL; };
  auto cond = [=](size_t ix) { return Flag ? ix != 0 : ix < 10; };
  auto iter = [=](size_t ix) {
    return Flag ? ix & ~(1ULL << __builtin_clzll(ix)) : ix + 1;
  };
#pragma unroll Flag ? 0 : N // Ok, allow 0.
  for (size_t ix = init(); cond(ix); ix = iter(ix)) {
    n *= n;
  }
#pragma GCC unroll Flag ? 0 : N // Ok, allow 0.
  for (size_t ix = init(); cond(ix); ix = iter(ix)) {
    n *= n;
  }
  return n;
}

int foo(int n) {
    return FailToBuild<true>(n);
}

int bar(int n) {
    return FailToBuild<false>(n);
}