Chris Angelico <ros...@gmail.com> writes:
>>> sys.version
'3.10.0b2+ (heads/3.10:33a7a24288, Jun 9 2021, 20:47:39) [GCC 8.3.0]'
>>> def chk(x):
... if not(0 < x < 10): raise Exception
...
>>> dis.dis(chk)
2 0 LOAD_CONST 1 (0)
2 LOAD_FAST 0 (x)
4 DUP_TOP
6 ROT_THREE
8 COMPARE_OP 0 (<)
10 POP_JUMP_IF_FALSE 11 (to 22)
12 LOAD_CONST 2 (10)
14 COMPARE_OP 0 (<)
16 POP_JUMP_IF_TRUE 14 (to 28)
18 LOAD_GLOBAL 0 (Exception)
20 RAISE_VARARGS 1
>> 22 POP_TOP
24 LOAD_GLOBAL 0 (Exception)
26 RAISE_VARARGS 1
>> 28 LOAD_CONST 0 (None)
30 RETURN_VALUE
>>>
Why are there two separate bytecode blocks for the "raise Exception"?
I'd have thought that the double condition would still be evaluated as
one thing, or at least that the jump destinations for both the
early-abort and the main evaluation should be the same.
Looks like in 3.8 it compiles more like the way you expected.
I didn't try 3.9, but it looks like a recent change to te compiler.
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