KOS_OP_JUMP_FALSE_FAST
Style: EXTRA (FASTVAR, LABEL, NOARG, NOARG). Row = fast slot, target pc.
Stack: No stack effect. Read the fast slot; if false, jump to the target, else advance. Raises
NameErrorwhen the slot is empty.Invariants: Jump locality for target.
Compiler form: Post-compile only: the
convert_fastlowering of JUMP_FALSE_VAR when the name has a fast slot.(if x ...),(when x ...),(while flag ...)and a bare-variable clause of a threadedand/ortest take one dispatch.
Example: (when x ...) with x in fast slot 0.
index |
opcode |
arg |
arg view |
comment |
|---|---|---|---|---|
0 |
JUMP_FALSE_FAST |
0 |
(fast 0 (“x”), -> 3, 0, 0) |
if x is false -> pc=3 |
1 |
CONST |
0 |
0 (1) |
body |
2 |
JUMP |
4 |
4 (-> 4) |
|
3 |
CONST |
1 |
1 (None) |
|
4 |
RETURN |
1 |
1 |