IN: scratchpad [
{ byte-array } declare
[ 0 alien-unsigned-4 32 shift ]
[ 4 alien-unsigned-4 ] bi bitor
64 >signed
] optimized.
! working
[
dup >R 0 alien-unsigned-4 32 fixnum-shift
R> 4 alien-unsigned-4 over tag 0 eq?
[ fixnum-bitor ] [ fixnum>bignum bignum-bitor ] if
18446744073709551615 >R >bignum R> bignum-bitand
dup 63 bignum-bit? [ 18446744073709551616 bignum- ] [ ] if
]
! broken
[
dup >R 0 alien-unsigned-4 32 fixnum-shift
R> 4 alien-unsigned-4 over tag 0 eq?
[ fixnum-bitor ] [ fixnum>bignum bignum-bitor ] if
dup 63 bignum-bit? [ 18446744073709551616 bignum- ] [ ] if
]
The second case correctly eliminates the bitand but incorrectly assumes
that the item on the stack (which is an integer -- either a fixnum or a
bignum), was converted to a bignum.
e256a4ba18