[Open64-devel] (no subject)

[Cheng, Bu Q. <bu....@in...>]

> > 		source file:
> >
> > 		static void bitfields();
> > 		struct fields
> > 		        {
> > 		        unsigned x1:1;
> > 		        unsigned x2:2;
> > 		        unsigned x3:3;
> > 		        unsigned   :1;          /* just because it can be
done */
> > 		        unsigned x4:4;
> > 		        };
> > 		struct fields *bf()
> > 		{
> > 		        static struct fields f;
> > 		        return(&f);
> > 		}
> > 		void bitfields()
> > 		{
> > 		        struct fields  *bf();
> > 		        Filename = "c35.c";
> > 		        bf()->x3 = 3;
> > 		        bf()->x2 = 2;
> > 		        iequals(0, bf()->x3 *= bf()->x2, 6);
> > 		}
> > 		main()
> > 		{
> > 		        bitfields();
> > 		}
   When doing,
     
             sgicc -ipa -O2 c35.c util.c -keep -show
     
            Result 
	          ***** Reached first test *****
       	  ERROR in c35.c at line 45: (4) != (6)       
  
         The bug is cause when doing ebo. ebo use
sxt_sequence()(ebo_special.cxx) to merge two instructions into one.
                 dep  r1 = r2, r3, pos1, leng1
                 extra.u r4 = r1, pos2, leng2            ---->   and_i
r4=r3, leng2
  
    sxt_sequence make a mistake. When pos1 <= pos2 &&  (pos1 + leng1) >=
(pos2 + leng2). It will do above merge. It's wrong since if 
pos1 < pos2 not '='(just like  the IR of c35.c). The merge will change the
semantic of  program. 

Thanks 

ChengBuQi