Switches xv5;
Release 1;
[ Main;
print "^Division Tester -- release 1 -- Andrew Plotkin -- this program is public domain^^";
print "This program tests signed multiplication, division, and modulo operations on the \
Z-machine. All these operations are supposed to be signed. (The Z-spec 0.2 erroneously \
says they are unsigned; see the Z-machine newsletter #1 for the correction.)^^";
print "I am assuming the convention that division always rounds towards zero (not towards \
negative infinity), and (A % B) always has the same sign as A. These conventions seem \
to be common among existing C/C++ compilers. (But they are not guaranteed by the C and C++ \
standards. Those only require that (A/B)*B + (A%B) == A, for all A and all nonzero B.)^^";
TestDiv();
print "^Hit any key to exit.^";
Pause();
quit;
];
[ Pause dummy;
@read_char 1 dummy;
return dummy;
];
[ TestOneLine str answer correct;
print (string) str, " = ", answer;
if (answer == correct)
print " (ok)^";
else
print " (should be ", correct, "!)^";
];
[ TestDiv x y z;
x = 13; y = 5; z = x * y;
TestOneLine("13 * 5", z, 65);
x = 13; y = -5; z = x * y;
TestOneLine("13 * -5", z, -65);
x = -13; y = 5; z = x * y;
TestOneLine("-13 * 5", z, -65);
x = -13; y = -5; z = x * y;
TestOneLine("-13 * -5", z, 65);
x = 13; y = 5; z = x / y;
TestOneLine("13 / 5", z, 2);
x = 13; y = -5; z = x / y;
TestOneLine("13 / -5", z, -2);
x = -13; y = 5; z = x / y;
TestOneLine("-13 / 5", z, -2);
x = -13; y = -5; z = x / y;
TestOneLine("-13 / -5", z, 2);
x = 13; y = 5; z = x % y;
TestOneLine("13 % 5", z, 3);
x = 13; y = -5; z = x % y;
TestOneLine("13 % -5", z, 3);
x = -13; y = 5; z = x % y;
TestOneLine("-13 % 5", z, -3);
x = -13; y = -5; z = x % y;
TestOneLine("-13 % -5", z, -3);
];