[LLVMdev] sext..to instruction

[Le Anh Quang]

Hi,
I have a question about the "sext..to" instruction. In the document, I found
two examples:
%x = sext i8 -1 to i16
It means:
i8 -1   = 1111 1111 --> 1111 1111 1111 1111 = i16
how can it determinate, that the i16 value %x positive is (65535)?
And the second example:

%y = sext i1 true to i32
1 --> 1111 1111 1111 1111 1111 1111 1111 1111
In this example, %y is -1

I'm not sure about it, when sext to results a positve/negative value?
Thank for any advice
Quang