------- Additional Comments From giovannibajo at libero dot it 2004-11-01 02:26
-------
The final tree dump of the loop with -O1 -fno-ivopts looks like this:
<L15>:;
nr = pathp->offset;
node = pathp->node;
D.7834 = &node->tags;
addr.9 = (volatile long int *) ((long unsigned int *) D.7834 + D.7838);
__asm__ __volatile__("btrl %1,%0":"=m" *addr.9:"dIr" nr);
D.7823 = node->tags[tag][0];
if (D.7823 != 0) goto out; else goto <L10>;
<L10>:;
pathp = pathp - 12B;
if (pathp->node != 0B) goto <L15>; else goto out;
With IV-OPTS, it is like this:
<L15>:;
nr = *ivtmp.124;
node = *((struct radix_tree_node * *) ivtmp.124 + -8B);
D.7834 = &node->tags;
addr.9 = (volatile long int *) ((long unsigned int *) D.7834 + D.7838);
__asm__ __volatile__("btrl %1,%0":"=m" *addr.9:"dIr" nr);
D.7823 = node->tags[tag][0];
if (D.7823 != 0) goto out; else goto <L10>;
Invalid sum of incoming frequencies 9667, should be 9550
<L10>:;
D.7820 = *ivtmp.128;
ivtmp.124 = ivtmp.124 - 12B;
ivtmp.128 = ivtmp.128 - 12B;
if (D.7820 != 0B) goto <L15>; else goto out;
It looks like the end condition is now checked on the pointer BEFORE
decrementing it, unless I am mistaken.
Zdenek, two questions:
- Aren't ivtmp.128 and ivtmp.124 duplicates?
- Since they behave exactly like pathp, there is a way to at least preserve the
variable name so that the code is easier to read?
--
What |Removed |Added
----------------------------------------------------------------------------
CC| |rakdver at gcc dot gnu dot
| |org, giovannibajo at libero
| |dot it
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18241
