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.
[ 0 15 [a,b] interval-contains? ] all?
] unit-test
-${ 0 255 [a,b] } [ 0 255 [a,b] dup interval-bitor ] unit-test
-${ 0 511 [a,b] } [ 0 256 [a,b] dup interval-bitor ] unit-test
+${ 0 256 [a,b] } [ 0 255 [a,b] dup interval-bitor ] unit-test
+${ 0 512 [a,b] } [ 0 256 [a,b] dup interval-bitor ] unit-test
${ -128 127 [a,b] } [ -128 127 [a,b] dup interval-bitor ] unit-test
${ -256 255 [a,b] } [ -128 128 [a,b] dup interval-bitor ] unit-test
: interval-bitor ( i1 i2 -- i3 )
[
{ { [ 2dup [ interval-nonnegative? ] both? ]
- [ [ max-lower-bound ] [ max-upper-bound ] 2bi bit-weight 1 - [a,b] ] }
+ ! FIXME: this should maybe be bitweight 1 -
+ [ [ max-lower-bound ] [ max-upper-bound ] 2bi bit-weight [a,b] ] }
{ [ 2dup [ interval-negative? ] both? ]
[ max-lower-bound -1 [a,b] ] }
[ interval-union interval-bit-weight [ neg ] [ 1 - ] bi [a,b] ]