Re: Using pointers with inline assembly in Ada

[NiGHTS <nights@unku.us>]

On Friday, June 10, 2022 at 9:39:44 AM UTC-4, Jeffrey R.Carter wrote:
> On 2022-06-09 23:30, NiGHTS wrote: 
> > 
> > declare 
> > type ff is array (0 .. 10) of Unsigned_32; 
> > pragma Pack(ff); 
> > Flags : aliased ff := (others => 0); 
> > Flag_Address : System.Address := Flags'Address; 
> > begin 
> > Asm ( "movl %0, %%eax" & 
> > "movl $1, (%%eax)" , 
> > Inputs => System.Address'Asm_Input ("g", Flag_Address), 
> > Clobber => "eax", 
> > Volatile => true 
> > ); 
> > Put_Line ("Output:" & Flags(0)'Img); 
> > end;
> Have you looked at the GNAT User's Guide section on this 
> (https://docs.adacore.com/live/wave/gnat_ugn/html/gnat_ugn/gnat_ugn/inline_assembler.html)? 
> I have never used this, but the first thing I notice is that the examples in the 
> User's Guide put an LF-HT pair between statements: 
> 
> Asm ("pushfl" & LF & HT & -- push flags on stack 
> "popl %%eax" & LF & HT & -- load eax with flags 
> "movl %%eax, %0", -- store flags in variable 
> Outputs => Unsigned_32'Asm_Output ("=g", Flags)); 
> 
> It is also legal to separate the statements with spaces, but what you have would 
> seem to be 
> 
> movl %0, %%eaxmovl $1, (%%eax) 
> 
> which may be a problem.
> -- 
> Jeff Carter 
> "I'm a lumberjack and I'm OK." 
> Monty Python's Flying Circus 
> 54
On my side I had the LF HT characters. I copied the code badly to this posting. So though you are right, my post lied a little bit by accident. This didn't end up being the main problem.