[sac-user] sac-visualization tool
Sven-Bodo Scholz
S.Scholz at herts.ac.uk
Fri Jun 13 05:57:56 BST 2008
On Thu, Jun 12, 2008 at 07:44:34PM +0800, Sunita Chandrasekaran wrote:
> and this:
> I am really confused sorting these declarations out...i was looking at
> sudoku.sac but I am still wondering how to go about declaration multiple
> variables
for argc/argv we have an emulation in a module CommandLine (see
http://www.sac-home.org/docs/libdoc/node61.html for details).
what exactly do you mean by multiple variables?
Do you refer to non-scalar arrays?
We have a type hierarchy to denote non scalar types. essentialy these
are element types followed by some shape restriction in square brackets.
e.g.
int[45] is the type of a 45 element vector
int[2,3] is the type of a 2 by 3 matrix
we also have more abstract types whose sytax is borrowed from regular
expressions e.g.
int[.] for int vectors
int[.,.,.] for 3 dimensional array
int[+] for non-scalar int arrays
int[*] for integer arrays that could be scalar
' hope that helps,
Bodo
>
> int main(int argc, char *argv[]);
>
> int msap (int **sequences, int *lengths, int *order, int first, int last,
> int longest,
> int matrix[max_unique_elements][max_unique_elements],
> int gapo_d, int gapx_d, int matave, int **scores);
>
>
> On Thu, Jun 12, 2008 at 5:12 PM, Sunita Chandrasekaran <sunisg123 at gmail.com>
> wrote:
>
> > how would you handle c pointers in sac?
> >
> > for eg (int **sequences, int *lengths, int *order )
> >
> >
> > On Thu, Jun 12, 2008 at 10:21 AM, Sunita Chandrasekaran <
> > sunisg123 at gmail.com> wrote:
> >
> >> Excellent Prof Scholz.
> >> Thanks to you for the explanation, yes am getting a hang of what sac can
> >> do. I think I will do some more coding myself to figure out what exactly is
> >> happening so that I can match that with these outputs.
> >>
> >> Something that I would definitely mention, is I am really v happy the way
> >> the compiler got installed, the installation just didn't break and hardly
> >> does this happen while installing a compiler or doing some
> >> cross-compilation.
> >>
> >> The compiler structure is well handled. Appreciate the sac team for this
> >> commendable effort taken.
> >>
> >> On Wed, Jun 11, 2008 at 8:09 PM, Sven-Bodo Scholz <S.Scholz at herts.ac.uk>
> >> wrote:
> >>
> >>> On Wed, Jun 11, 2008 at 03:32:39PM +0800, Sunita Chandrasekaran wrote:
> >>> > Hi
> >>> >
> >>> > Does this sac2c compiler come with any graphic analyzer tool?
> >>> > How do you view the graphs or the optimization effects? vcg?
> >>>
> >>> Hi Sunita,
> >>>
> >>> there are 2 things you might want to visualize: a) programs
> >>> b) data (i.e. arrays)
> >>>
> >>> For the latter, we use off-the-shelve tools that exist as C libraries
> >>> such as SDL or DISLIN.
> >>>
> >>> However, I assume that you are interested in the former since you
> >>> mentioned vcg. AFAIK, there exists no graphical tol to visualise SaC
> >>> programs. BUT, we have built-in support for printing optimised programs
> >>> as SaC code itself. if you use 'sac2c -h' you will get lots of possible
> >>> compiler flags include the BREAK-options -b<xyz>.
> >>> Be aware though that the further "down" in the compilation process that
> >>> you break the more difficult to relate to the original program the code
> >>> becomes.
> >>>
> >>> Here a quick example to get started:
> >>>
> >>> Let's look at the following program:
> >>>
> >>>
> >>> --------------------------------------------------------------------------------
> >>> use Array: all;
> >>>
> >>> int main()
> >>> {
> >>> a = 0;
> >>>
> >>> for( i=0; i<10; i++) {
> >>> a += i;
> >>> }
> >>> return( a);
> >>> }
> >>>
> >>> --------------------------------------------------------------------------------
> >>>
> >>> sac2c -b3 sunita.sac gives
> >>>
> >>>
> >>> --------------------------------------------------------------------------------
> >>> [.... lots of "gibberish"....]
> >>> /*
> >>> * function definitions (FUNDEFS)
> >>> */
> >>>
> >>> int _MAIN::main()
> >>> /*
> >>> * main :: ---
> >>> */
> >>> {
> >>> a = 0;
> >>> i = 0;
> >>> while (i Array::< 10)
> >>> {
> >>> a = Array::+( a, i);
> >>> i = Array::+( i, 1);
> >>> }
> >>> return( a);
> >>> }
> >>>
> >>> --------------------------------------------------------------------------------
> >>>
> >>> sac2c -b6 sunita.sac gives
> >>>
> >>>
> >>> --------------------------------------------------------------------------------
> >>> [.... lots of "gibberish"....]
> >>> /*
> >>> * function definitions (FUNDEFS)
> >>> */
> >>>
> >>> /* Loop function */
> >>> int _MAIN::_dup_5_main__Loop_0( int a, int i)
> >>> /*
> >>> * _dup_5_main__Loop_0 :: ---
> >>> */
> >>> {
> >>> int a__SSA0_3;
> >>> int a__SSA0_2;
> >>> int i__SSA0_1;
> >>> int a__SSA0_1;
> >>> int{1} _flat_2;
> >>> int{10} _flat_4;
> >>> bool _flat_3;
> >>>
> >>> a__SSA0_1 = wrapper:Array::+( a, i);
> >>> _flat_2 = 1;
> >>> i__SSA0_1 = wrapper:Array::+( i, _flat_2);
> >>> _flat_4 = 10;
> >>> _flat_3 = wrapper:Array::<( i__SSA0_1, _flat_4);
> >>> if (_flat_3)
> >>> {
> >>> a__SSA0_2 = _MAIN::_dup_5_main__Loop_0( a__SSA0_1, i__SSA0_1);
> >>> }
> >>> else
> >>> {
> >>> /* empty */
> >>> }
> >>> a__SSA0_3 = ( _flat_3 ? a__SSA0_2 : a__SSA0_1 );
> >>> return( a__SSA0_3);
> >>> }
> >>>
> >>> /* Cond function */
> >>> int _MAIN::main__Cond_1( int{0} a, int{0} i, bool _flat_0)
> >>> /*
> >>> * main__Cond_1 :: ---
> >>> */
> >>> {
> >>> int a__SSA0_2;
> >>> int a__SSA0_1;
> >>>
> >>> if (_flat_0)
> >>> {
> >>> a__SSA0_1 = _MAIN::_dup_5_main__Loop_0( a, i);
> >>> }
> >>> else
> >>> {
> >>> /* empty */
> >>> }
> >>> a__SSA0_2 = ( _flat_0 ? a__SSA0_1 : a );
> >>> return( a__SSA0_2);
> >>> }
> >>>
> >>> int _MAIN::main()
> >>> /*
> >>> * main :: ---
> >>> */
> >>> {
> >>> int a__SSA0_2;
> >>> int a__SSA0_1;
> >>> bool _flat_0;
> >>> int{10} _flat_1;
> >>> int{0} i;
> >>> int{0} a;
> >>>
> >>> a = 0;
> >>> i = 0;
> >>> _flat_1 = 10;
> >>> _flat_0 = wrapper:Array::<( i, _flat_1);
> >>> a__SSA0_1 = _MAIN::main__Cond_1( a, i, _flat_0);
> >>> a__SSA0_2 = _type_conv_( int, a__SSA0_1);
> >>> return( a__SSA0_2);
> >>> }
> >>>
> >>> --------------------------------------------------------------------------------
> >>>
> >>> Here you can see that our compiler has transformed the loop into a tail
> >>> recursive function called _MAIN::_dup_5_main__Loop_0. You can also see
> >>> what the type inference has found out.
> >>> Notice here as well that, on this level, we may have things that are
> >>> exceed the set of user-level SaC. An example are types of the form
> >>> int{0} a which indicates that a has the value 0!
> >>>
> >>> If we preceed and let the optimiser do its job, i.e.
> >>> sac2c -b11 sunita.sac, we obtain:
> >>>
> >>>
> >>> --------------------------------------------------------------------------------
> >>> [ I am picking the relevant parts here :-) ]
> >>>
> >>> int _MAIN::main()
> >>> /*
> >>> * main :: ---
> >>> */
> >>> {
> >>> int a__SSA0_1;
> >>> int{0} a;
> >>>
> >>> a = 0;
> >>> a__SSA0_1 = _MAIN::_dup_279__main__Loop_0( a, a);
> >>> return( a__SSA0_1);
> >>> }
> >>>
> >>> int _MAIN::_dup_279__main__Loop_0( int a, int i)
> >>> /*
> >>> * _dup_279__main__Loop_0 :: ---
> >>> */
> >>> {
> >>> int _pinl_19__flat_69;
> >>> int _pinl_20__flat_69;
> >>> bool _pinl_21__flat_42;
> >>> int a__SSA0_3;
> >>> int a__SSA0_2;
> >>>
> >>> _pinl_19__flat_69 = _add_SxS_( a, i);
> >>> _pinl_20__flat_69 = _add_SxS_( i, 1);
> >>> _pinl_21__flat_42 = _lt_SxS_( _pinl_20__flat_69, 10);
> >>> if (_pinl_21__flat_42)
> >>> {
> >>> a__SSA0_2 = _MAIN::_dup_279__main__Loop_0( _pinl_19__flat_69,
> >>> _pinl_20__flat_69);
> >>> }
> >>> else
> >>> {
> >>> /* empty */
> >>> }
> >>> a__SSA0_3 = ( _pinl_21__flat_42 ? a__SSA0_2 : _pinl_19__flat_69 );
> >>> return( a__SSA0_3);
> >>> }
> >>>
> >>>
> >>> --------------------------------------------------------------------------------
> >>> Usually, you do NOT want to see any code thereafter because our C-code
> >>> generator is rather generic and therefore the intermediate code becomes
> >>> ebven less readable to the "untrained eye" ;-)
> >>>
> >>> If you want to tweak the optimisation you could, for example, increase
> >>> the loop unrolling threshold by using
> >>>
> >>> sac2c -maxlur 10 -b11 sunita.sac
> >>>
> >>> In which case you obtain:
> >>>
> >>> --------------------------------------------------------------------------------
> >>> [...gibberish...]
> >>>
> >>> int{45} _MAIN::main()
> >>> /*
> >>> * main :: ---
> >>> */
> >>> {
> >>> int{45} a__SSA0_1;
> >>>
> >>> a__SSA0_1 = 45;
> >>> return( a__SSA0_1);
> >>> }
> >>>
> >>> --------------------------------------------------------------------------------
> >>>
> >>> ' hope that you were after some way to get this kind of information
> >>> about about the optimisation results....
> >>>
> >>> Cheers,
> >>> Bodo
> >>>
> >>>
> >>
> >
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