// operator precedence and associativity, the same in both compilers. every binary // operator is placed next to its neighbours in the table and between two of the same // kind, so a wrong binding changes a printed number. src/tools/parity.sh compiles // this program with zc0 and with the self-hosted compiler and compares the output. // it stays inside zc0's subset: no ?: (zc0 has none), no types beyond int. // // the table, tightest first: unary - ! ~ * &, then * / %, + -, << >>, < > <= >=, // == !=, &, ^, |, &&, ||, then the assignments, which group to the right. every // binary operator groups to the left. the expected output follows the c rules and // was checked by compiling the same expressions with a c compiler. namespace; include rt; int trace, calls; int seen(int v) { calls++; trace = trace * 10 + v; return v; } int id(int v) { return v; } int out(int v) { rt.put_n(v); rt.put_c(32); return v; } int endl() { rt.put_c(10); return 0; } int main() { // operands the compilers cannot fold away int a = id(2), b = id(3), c = id(4), e = id(5), z = id(0), one = id(1); // * / % against + -, and left grouping out(a + b * c); out(a * b + c); out(a - b * c); out(a * b - c); out((a + b) * c); out(id(100) - 30 - 20); out(1 - 2 + 3); out(id(100) / 5 / 2); out(id(20) / 3 * 3); out(a * b % c); out(id(100) % 7 % 3); out(id(100) / 10 % 4); out(id(7) % 4 * 3); endl(); // + - against << >>, and left grouping out(one << a + one); out(id(32) >> a - one); out(one << a << b); out(id(256) >> a >> one); out(one << b * a); out(id(8) >> one << one); endl(); // shifts against < > <= >=, and the relational chain out(one << a < e); out(id(16) >> one > 7); out(a < b < c); out(e > c > b); out(z <= e <= z); out(a >= b >= z); endl(); // relations against == !=, and the equality chain out(a < b == one); out(one == a > b); out(e == e == one); out(b != c != one); out(id(3) > a == one < a); endl(); // == against & ^ | out(c & c == c); out(one | a == a); out(b ^ b == b); out(a == a & one); out(c != z | z); endl(); // & ^ | against each other, and against + and << out(c | b & one); out(id(7) ^ e & b); out(one | 6 ^ b); out(id(6) & b | 8); out(a + 6 & c); out(one & b << one); out(id(12) | one << a); endl(); // && and || against | & and each other; the result of both is 0 or 1 out(one || z && z); out(z && z || one); out(z || one && one || z); out(z && one | one); out(one || z & z); out(b && c); out(b & c); out(z || id(9)); out(id(7) && id(8) && z); out(a < b && c < e || z); out(z == z || z && z); endl(); // unary operators out(-a * b); out(- -b); out(-a + e); out(!z + one); out(!a == z); out(!!id(7)); out(~z & 255); out(~one + one); out(~a & 7); out(-a * -b); out(a - -b); out(-id(7) % 4); out(!(a < b) + one); out(*&a + one); out(-*&b); endl(); // assignment groups to the right and takes the whole expression on its right int x, y, w; x = y = w = id(7); out(x); out(y); out(w); x = id(10); x -= 3 - 1; out(x); x *= a + b; out(x); x <<= one + one; out(x); x |= one << b; out(x); x += y -= 2; out(x); out(y); x = id(100); x /= a * b; out(x); x %= 7 - 2; out(x); x = id(6); x &= 3 | 8; out(x); x ^= 1 + 2 * 3; out(x); x = id(255); x >>= 2 + 2; out(x); endl(); // division, remainder and shifts of negative numbers out(id(0) - 7 / 2); out((id(0) - 7) / 2); out((id(0) - 7) % 3); out(id(7) % (id(0) - 3)); out((id(0) - 8) >> 1); out((id(0) - 8) << 1); endl(); // short circuit: how many operands ran, and in what order calls = 0; trace = 0; x = seen(0) && seen(1); out(x); out(calls); out(trace); calls = 0; trace = 0; x = seen(1) || seen(2); out(x); out(calls); out(trace); calls = 0; trace = 0; x = seen(1) || seen(2) && seen(3); out(x); out(calls); out(trace); calls = 0; trace = 0; x = seen(0) || seen(2) && seen(3); out(x); out(calls); out(trace); calls = 0; trace = 0; x = seen(0) && seen(2) || seen(3); out(x); out(calls); out(trace); calls = 0; trace = 0; x = seen(1) && seen(0) || seen(2) && seen(3); out(x); out(calls); out(trace); calls = 0; trace = 0; x = seen(1) | seen(2) && seen(0) & seen(3); out(x); out(calls); out(trace); endl(); // operands run left to right whatever their binding calls = 0; trace = 0; x = seen(1) + seen(2) * seen(3) - seen(4); out(x); out(calls); out(trace); calls = 0; trace = 0; x = seen(1) << seen(2) < seen(3) == seen(4); out(x); out(calls); out(trace); calls = 0; trace = 0; x = out(seen(1) - seen(2)) * out(seen(3)); out(x); out(calls); out(trace); endl(); return 0; }