On Tue, 2007-04-10 at 19:54 +0200, J.C. Pizarro wrote: > Hi Diego Novillo > > Your "Tuple representation" of the GIMPLE instructions was: > HEADER: > code 16 bits > subcode 16bits > next word > prev word > bb word > locus word > block word > BODY: > OP0 word > .. > OPN word > > I've a little idea, > > Can i remove the word "prev"? > Thanks to "bb", i can traverse the short list of > the small basic block getted from its hashtable.
Do you mean implement this as a single linked list and then to find the previous instruction, start at the beginning of the block and traverse forward? Back in the early days of tree-ssa we did such a thing with the tree iterators. It was too slow. there are many LARGE basic blocks which make the computation too expensive for any pass that goes backwards through a block. Andrew
