Re: Is const_int zero extended or sign-extended?

[Dave Korn <dave dot korn dot cygwin at googlemail dot com>]

Bingfeng Mei wrote:
> Hello, I am confused by one very basic concept :).  In the following rtx
> expression, if const_int is 32-bit and DImode is 64-bit, will the const_int
> sign-extended or zero-extended. In other word, is the content of reg:DI 95
> 0xffffffffffffffff9 or 0xffffffff9 after this instruction?
> 
> (set:DI (reg:DI 95) (const_int -7 [0xfffffff9]))
> 
> Thanks, Bingfeng Mei
> 

  IIUC in the absence of any explicit extension operation, a const_int is
taken to be whatever size the object it is assigned to, with the value given
by the signed decimal interpretation.  That RTL sets reg 95 to a DImode -7.

  Is this part of a larger problem?

    cheers,
      DaveK