1 Optimisation Prerequisites and Effect
2 ------------ ------------------------
3
4 constant_storage value instruction references a constant;
5 (guidance) storage instruction references a constant;
6 | indicate whether both instructions satisfy the
7 | preconditions and should be removed (although
8 | this currently involves just a single merged
9 | instruction)
10
11 constant_accessor value instruction references a constant;
12 (guidance) | target name provided (for use in producing an
13 | address access instruction)
14
15 known_target value instruction references a constant;
16 (guidance) | target and context are provided (no instructions
17 | are removed)
18
19 self_access value instruction references "self" in a method;
20 (guidance) specified attribute name always has the same
21 position;
22 | indicate whether an appropriate instruction can
23 | be generated for the access
24
25 temp_storage value instruction is a simple input operation;
26 (elimination) value instruction is the last instruction;
27 (guidance) | remove the value instruction, provide the value
28 | instruction in place of a temporary storage
29 | reference
30
31 load_operations value instruction is a simple input operation;
32 (merge) value instruction is the last instruction;
33 current instruction uses simple input;
34 | remove the value instruction, make the value
35 | instruction the input to the current instruction
36
37 no_operations input to the current instruction loads from the
38 (guidance) destination of the current instruction;
39 | indicate that the current instruction should be
40 | omitted
41
42 unused_results value instruction is a simple input operation;
43 (elimination) value instruction is the final instruction of a
44 discarded expression;
45 | remove the value instruction
46
47 unused_objects attribute is defined using a name which is not
48 (inspection) used in an active region of the program or is
49 defined within a class which is not used by
50 the program, object is unambiguously
51 referenced by such attributes
52 | remove such attributes and objects
