machine dependent left shift results

On a 32 bit machine, ~0<<32 gives 11111111111111111111111111111111 (I was
expecting 0)

(~0<<31)<<1 gives 0.

I was trying ~(~0<<$size) to create a mask of $size ones.

((1<<$size) -1) was what I tried first but it also failed for the same
reason, I guess.

I like that in verilog I can just say {$size{1'b1}}

I know I can use Math::BigInt, but I still wonder what the rationale is
behind the first example failing.

EC

easily_confused

reposted on comp.lang.perl.misc
please respond there


"easily_confused" <> wrote in message
news:003ff6be$0$32523$...
> On a 32 bit machine, ~0<<32 gives 11111111111111111111111111111111 (I was
> expecting 0)
>
> (~0<<31)<<1 gives 0.
>
> I was trying ~(~0<<$size) to create a mask of $size ones.
>
> ((1<<$size) -1) was what I tried first but it also failed for the same
> reason, I guess.
>
> I like that in verilog I can just say {$size{1'b1}}
>
> I know I can use Math::BigInt, but I still wonder what the rationale is
> behind the first example failing.
>
> EC
>
>
>

easily_confused