[Mesa-dev] [PATCH] glsl: fix lowering conditional returns in subroutines

[Fabian Bieler]

Hello!

This patch fixes a bug in the lower_jumps pass if lower_sub_return is set to 
true.

Subroutines such as

void sub() {
  for (int i = 0; i < 2; ++i) {
    if (i)
      return;
  }
}

a continue instruction is inserted outside of the loop.

Subroutines such as

void sub() {
  for (int j = 0; j < 2; ++j) {
    for (int i = 0; i < 2; ++i) {
      if (i)
        return;
    }
  }
  alter_some_global_variable();
  return;
}

get transformed to

void sub() {
  bool return_flag = false;
  for (int j = 0; j < 2; ++j) {
    for (int i = 0; i < 2; ++i) {
      if (i) {
        return_flag = true;
        break;
      }
    }
    if (return_flag)
      break;
  }
  alter_some_global_variable();
  return;
}

Please review

Fabian
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