x y * dup *
dstack.push(x); // x
dstack.push(y); // y
dstack.push(dstack.pop() * dstack.pop()); // *
var t = dstack.pop(); dstack.push(t); dstack.push(t); // dup
dstack.push(dstack.pop() * dstack.pop()); // *
var result = dstack.pop();
dstack.push(x); // x
dstack.push(y * dstack.pop()); // *
var t = dstack.pop(); dstack.push(t); dstack.push(t); // dup
dstack.push(dstack.pop() * dstack.pop()); // *
var result = dstack.pop();
dstack.push(y * x); // *
var t = dstack.pop(); dstack.push(t); dstack.push(t); // dup
dstack.push(dstack.pop() * dstack.pop()); // *
var result = dstack.pop();
var t = y * x; dstack.push(t); dstack.push(t); // dup
dstack.push(dstack.pop() * dstack.pop()); // *
var result = dstack.pop();
var t = y * x; dstack.push(t);
dstack.push(t * dstack.pop());
var result = dstack.pop();
var t = y * x;
dstack.push(t * t);
var result = dstack.pop();
var t = y * x;
var result = t * t;
aaaa if bbbb else cccc then dddd
Optimize Wisely
Keep a compile time dstack + rstack
Walk the Haiku in order
Push / pop whole expressions
Push dstack + rstack to a conditional stack
Require both branches match
Make each entry unique
[ ]
dstack.push(x); // x
dstack.push(y); // y
dstack.push(dstack.pop() * dstack.pop()); // *
var t = dstack.pop(); dstack.push(t); dstack.push(t); // dup
dstack.push(dstack.pop() * dstack.pop()); // *
var result = dstack.pop();
[ x ]
dstack.push(y); // y
dstack.push(dstack.pop() * dstack.pop()); // *
var t = dstack.pop(); dstack.push(t); dstack.push(t); // dup
dstack.push(dstack.pop() * dstack.pop()); // *
var result = dstack.pop();
[ x | y ]
dstack.push(dstack.pop() * dstack.pop()); // *
var t = dstack.pop(); dstack.push(t); dstack.push(t); // dup
dstack.push(dstack.pop() * dstack.pop()); // *
var result = dstack.pop();
[ x ]
dstack.push(y * dstack.pop()); // *
var t = dstack.pop(); dstack.push(t); dstack.push(t); // dup
dstack.push(dstack.pop() * dstack.pop()); // *
var result = dstack.pop();
[ ]
dstack.push(y * x); // *
var t = dstack.pop(); dstack.push(t); dstack.push(t); // dup
dstack.push(dstack.pop() * dstack.pop()); // *
var result = dstack.pop();
[ y * x ]
var t = dstack.pop(); dstack.push(t); dstack.push(t); // dup
dstack.push(dstack.pop() * dstack.pop()); // *
var result = dstack.pop();
[ ]
var t = y * x; dstack.push(t); dstack.push(t); // dup
dstack.push(dstack.pop() * dstack.pop()); // *
var result = dstack.pop();
[ t ]
var t = y * x; dstack.push(t);
dstack.push(dstack.pop() * dstack.pop()); // *
var result = dstack.pop();
[ t | t ]
var t = y * x;
dstack.push(dstack.pop() * dstack.pop()); // *
var result = dstack.pop();
[ t ]
var t = y * x;
dstack.push(t * dstack.pop()); // *
var result = dstack.pop();
[ ]
var t = y * x;
dstack.push(t * t); // *
var result = dstack.pop();
[ t * t ]
var t = y * x;
var result = dstack.pop();
[ ]
var t = y * x;
var result = t * t;
if ... else ... then
{ }
[ ]
aaaa if bbbb else cccc then dddd
{ }
[ aaaa ]
A if bbbb else cccc then dddd
{ [ aaaa ],orig }
[ ]
A if(x){ bbbb else cccc then dddd
{ [ aaaa ],orig }
[ bbbb ]
A if(x){ B else cccc then dddd
{ [ bbbb ],orig }
[ ]
A if(x){ B }else{ cccc then dddd
{ [ bbbb ],orig }
[ cccc ]
A if(x){ B }else{ C then dddd
{ }
[ ]
A VARS! if(x){ B }else{ C } VARS@ dddd
{ }
[ dddd ]
A VARS! if(x){ B }else{ C } VARS@ D
Possibilities
Support loops
Support function calls
Apply to registers
⚘
Thank you
Haiku Monthly August 22, 2015 Brad Nelson / @flagxor