The following patch finally removes the reference dependence check cache.
Its benefit is too low for its cost. LIM Compile-time for PR39326
improves from 100s to 50s and LIMs memory use drops to unnoticable
(from 915MB memory use after LIM to 380MB memory use after LIM).
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2013-03-22 Richard Biener <rguent...@suse.de>
* tree-ssa-loop-im.c (struct mem_ref): Remove indep_ref and
dep_ref members.
(mem_ref_alloc): Do not allocate them.
(refs_independent_p): Do not query or maintain a cache.
Index: trunk/gcc/tree-ssa-loop-im.c
===================================================================
*** trunk.orig/gcc/tree-ssa-loop-im.c 2013-03-22 12:25:13.633716049 +0100
--- trunk/gcc/tree-ssa-loop-im.c 2013-03-22 12:35:18.086448436 +0100
*************** typedef struct mem_ref
*** 134,143 ****
If it is only loaded, then it is independent
on all stores in the loop. */
bitmap dep_loop; /* The complement of INDEP_LOOP. */
-
- bitmap indep_ref; /* The set of memory references on that
- this reference is independent. */
- bitmap dep_ref; /* The complement of INDEP_REF. */
} *mem_ref_p;
/* We use two bits per loop in the ref->{in,}dep_loop bitmaps, the first
--- 134,139 ----
*************** mem_ref_alloc (tree mem, unsigned hash,
*** 1482,1489 ****
ref->stored = BITMAP_ALLOC (&lim_bitmap_obstack);
ref->indep_loop = BITMAP_ALLOC (&lim_bitmap_obstack);
ref->dep_loop = BITMAP_ALLOC (&lim_bitmap_obstack);
- ref->indep_ref = BITMAP_ALLOC (&lim_bitmap_obstack);
- ref->dep_ref = BITMAP_ALLOC (&lim_bitmap_obstack);
ref->accesses_in_loop.create (0);
return ref;
--- 1478,1483 ----
*************** refs_independent_p (mem_ref_p ref1, mem_
*** 2228,2260 ****
if (ref1 == ref2)
return true;
- /* Reference dependence in a loop is symmetric. */
- if (ref1->id > ref2->id)
- {
- mem_ref_p tem = ref1;
- ref1 = ref2;
- ref2 = tem;
- }
-
- if (bitmap_bit_p (ref1->indep_ref, ref2->id))
- return true;
- if (bitmap_bit_p (ref1->dep_ref, ref2->id))
- return false;
-
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "Querying dependency of refs %u and %u: ",
ref1->id, ref2->id);
if (mem_refs_may_alias_p (ref1, ref2, &memory_accesses.ttae_cache))
{
- bitmap_set_bit (ref1->dep_ref, ref2->id);
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "dependent.\n");
return false;
}
else
{
- bitmap_set_bit (ref1->indep_ref, ref2->id);
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "independent.\n");
return true;
--- 2222,2239 ----
