page align

page align

[mudongliang]

Hello everyone :
      Is there any solution to support page align in the gas ??
      For example , I have a test.s file ! If I want several
instructions only in one page , padding if no one page !
      Thanks in advance!
mudongliangabcd

Re: page align

[Nicholas Clifton]

Hi mudongliang,

>        Is there any solution to support page align in the gas ??
>        For example , I have a test.s file ! If I want several
> instructions only in one page , padding if no one page !
>        Thanks in advance!

It sounds as if you want to use the .p2align pseudo op.  The GAS 
documentation says this about it:


   .p2align[wl] <abs-expr> [, <abs-expr> [, <abs-expr>]]

   Pad the location counter (in the current subsection) to a particular
   storage boundary.  The first expression (which must be absolute) is
   the number of low-order zero bits the location counter must have after
   advancement.  For example ".p2align 3" advances the location
   counter until it a multiple of 8.  If the location counter is already
   a multiple of 8, no change is needed.

   The second expression (also absolute) gives the fill value to be
   stored in the padding bytes.  It (and the comma) may be omitted.  If
   it is omitted, the padding bytes are normally zero.  However, on some
   systems, if the section is marked as containing code and the fill
   value is omitted, the space is filled with no-op instructions.

   The third expression is also absolute, and is also optional.  If it
   is present, it is the maximum number of bytes that should be skipped
   by this alignment directive.  If doing the alignment would require
   skipping more bytes than the specified maximum, then the alignment is
   not done at all.  You can omit the fill value (the second argument)
   entirely by simply using two commas after the required alignment;
   this can be useful if you want the alignment to be filled with no-op
   instructions when appropriate.

Cheers
   Nick