//: Jump primitives
:(scenario jump_can_skip_instructions)
recipe main [
jump 1:offset
1:number <- copy 1:literal
]
+run: jump 1:offset
-run: 1:number <- copy 1:literal
-mem: storing 1 in location 1
:(before "End Primitive Recipe Declarations")
JUMP,
:(before "End Primitive Recipe Numbers")
Recipe_number["jump"] = JUMP;
:(before "End Primitive Recipe Implementations")
case JUMP: {
assert(current_instruction().ingredients.at(0).initialized);
assert(SIZE(ingredients) == 1);
assert(scalar(ingredients.at(0)));
instruction_counter += ingredients.at(0).at(0);
trace(Primitive_recipe_depth, "run") << "jumping to instruction " << instruction_counter+1;
break;
}
//: special type to designate jump targets
:(before "End Mu Types Initialization")
Type_number["offset"] = 0;
:(scenario jump_backward)
recipe main [
jump 1:offset # 0 -+
jump 3:offset # | +-+ 1
# \/ /\ |
jump -2:offset # 2 +-->+ |
] # \/ 3
+run: jump 1:offset
+run: jump -2:offset
+run: jump 3:offset
:(before "End Primitive Recipe Declarations")
JUMP_IF,
:(before "End Primitive Recipe Numbers")
Recipe_number["jump-if"] = JUMP_IF;
:(before "End Primitive Recipe Implementations")
case JUMP_IF: {
assert(current_instruction().ingredients.at(1).initialized);
assert(SIZE(ingredients) == 2);
assert(scalar(ingredients.at(0)));
if (!ingredients.at(0).at(0)) {
trace(Primitive_recipe_depth, "run") << "jump-if fell through";
break;
}
assert(scalar(ingredients.at(1)));
instruction_counter += ingredients.at(1).at(0);
trace(Primitive_recipe_depth, "run") << "jumping to instruction " << instruction_counter+1;
break;
}
:(scenario jump_if)
recipe main [
jump-if 999:literal, 1:offset
123:number <- copy 1:literal
]
+run: jump-if 999:literal, 1:offset
+run: jumping to instruction 2
-run: 1:number <- copy 1:literal
-mem: storing 1 in location 123
:(scenario jump_if_fallthrough)
recipe main [
jump-if 0:literal, 1:offset
123:number <- copy 1:literal
]
+run: jump-if 0:literal, 1:offset
+run: jump-if fell through
+run: 123:number <- copy 1:literal
+mem: storing 1 in location 123
:(before "End Primitive Recipe Declarations")
JUMP_UNLESS,
:(before "End Primitive Recipe Numbers")
Recipe_number["jump-unless"] = JUMP_UNLESS;
:(before "End Primitive Recipe Implementations")
case JUMP_UNLESS: {
assert(current_instruction().ingredients.at(1).initialized);
assert(SIZE(ingredients) == 2);
assert(scalar(ingredients.at(0)));
if (ingredients.at(0).at(0)) {
trace(Primitive_recipe_depth, "run") << "jump-unless fell through";
break;
}
assert(scalar(ingredients.at(1)));
instruction_counter += ingredients.at(1).at(0);
trace(Primitive_recipe_depth, "run") << "jumping to instruction " << instruction_counter+1;
break;
}
:(scenario jump_unless)
recipe main [
jump-unless 0:literal, 1:offset
123:number <- copy 1:literal
]
+run: jump-unless 0:literal, 1:offset
+run: jumping to instruction 2
-run: 123:number <- copy 1:literal
-mem: storing 1 in location 123
:(scenario jump_unless_fallthrough)
recipe main [
jump-unless 999:literal, 1:offset
123:number <- copy 1:literal
]
+run: jump-unless 999:literal, 1:offset
+run: jump-unless fell through
+run: 123:number <- copy 1:literal
+mem: storing 1 in location 123