These instructions are used for boolean operations, either explicit a or b or implicit a < b < c.

We should remove these instructions for a few reasons:

• These two bytecodes represent only 0.2% of all instructions.
• They add quite a lot of complexity to the compiler
• PEP 669 requires an instrumented version of all jumps, so removing them will remove 4 instructions, not just 2.
• They can be trivially replaced: JUMP_IF_FALSE_OR_POP becomes COPY 1; POP_JUMP_IF_FALSE; POP_TOP.

We can avoid generating much, if any, extra code by better peephole optimization, or more sophisticated code generation.

Possible optimizations

Code generation

If there are no walrus expressions (x := ...) in the statement, then LOAD_FAST instructions can be freely re-ordered and duplicated.
a < b < c can be implemented as (a < b) or (b < c) without the need to store b on the stack.

Currently we generate the sequence:

 LOAD_FAST 0 (a) LOAD_FAST 1 (b) SWAP 2 COPY 2 COMPARE (<) POP_JUMP_IF_FALSE LOAD_FAST 2 (c) COMPARE (<) POP_JUMP_IF_FALSE 

We could generate:

 LOAD_FAST 0 (a) LOAD_FAST 1 (b) COMPARE (<) POP_JUMP_IF_FALSE LOAD_FAST 1 (b) LOAD_FAST 2 (c) COMPARE (<) POP_JUMP_IF_FALSE 

CFG optimization

The sequence:

 LOAD_FAST 0 (a) LOAD_FAST 1 (b) SWAP 2 

can be changed to:

 LOAD_FAST 1 (b) LOAD_FAST 0 (a) 

The sequence:

 LOAD_FAST a COPY 1 POP_JUMP_IF_FALSE label POP_TOP ... label: ... 

can be changed to:

 LOAD_FAST a POP_JUMP_IF_FALSE label ... label: LOAD_FAST a ... 

(Provided that label has only one predecessor)