===================================================================
@@ -5415,29 +5415,23 @@ iv_ca_set_cp (struct ivopts_data *data, struct iv_
}
/* Extend set IVS by expressing USE by some of the candidates in it
- if possible. All important candidates will be considered
- if IMPORTANT_CANDIDATES is true. */
+ if possible. Consider all important candidates if candidates in
+ set IVS don't give any result. */
static void
iv_ca_add_use (struct ivopts_data *data, struct iv_ca *ivs,
- struct iv_use *use, bool important_candidates)
+ struct iv_use *use)
{
struct cost_pair *best_cp = NULL, *cp;
bitmap_iterator bi;
- bitmap cands;
unsigned i;
gcc_assert (ivs->upto >= use->id);
+ ivs->upto++;
+ ivs->bad_uses++;
- if (ivs->upto == use->id)
+ EXECUTE_IF_SET_IN_BITMAP (ivs->cands, 0, i, bi)
{
- ivs->upto++;
- ivs->bad_uses++;
- }
-
- cands = (important_candidates ? data->important_candidates : ivs->cands);
- EXECUTE_IF_SET_IN_BITMAP (cands, 0, i, bi)
- {
struct iv_cand *cand = iv_cand (data, i);
cp = get_use_iv_cost (data, use, cand);
@@ -5445,6 +5439,17 @@ iv_ca_add_use (struct ivopts_data *data, struct iv
if (cheaper_cost_pair (cp, best_cp))
best_cp = cp;
}
+
+ if (best_cp == NULL)
+ {
+ EXECUTE_IF_SET_IN_BITMAP (data->important_candidates, 0, i, bi)
+ {
+ cand = iv_cand (data, i);
+ cp = get_use_iv_cost (data, use, cand);
+ if (cheaper_cost_pair (cp, best_cp))
+ best_cp = cp;
+ }
+ }
iv_ca_set_cp (data, ivs, use, best_cp);
}
@@ -5878,18 +5883,9 @@ try_add_cand_for (struct ivopts_data *data, struct
struct iv_ca_delta *best_delta = NULL, *act_delta;
struct cost_pair *cp;
- iv_ca_add_use (data, ivs, use, false);
+ iv_ca_add_use (data, ivs, use);
best_cost = iv_ca_cost (ivs);
-
cp = iv_ca_cand_for_use (ivs, use);
- if (!cp)
- {
- ivs->upto--;
- ivs->bad_uses--;
- iv_ca_add_use (data, ivs, use, true);
- best_cost = iv_ca_cost (ivs);
- cp = iv_ca_cand_for_use (ivs, use);
- }
if (cp)
{
best_delta = iv_ca_delta_add (use, NULL, cp, NULL);
Hi, As I analyzed in bug pr62178, current candidate selecting algorithm can't find out the optimal solution in some scenarios. I am trying to improve it but before that, I need to clean up the interface of iv_ca_add_use and the calls to it. The two calls to the function are controlled by a boolean argument, and the second call is always fired if the first one doesn't give any result. This patch encapsulates logic of the two calls into function iv_ca_add_use and cleanups the interface. Another change is remove the check in below code. gcc_assert (ivs->upto >= use->id); if (ivs->upto == use->id) { ivs->upto++; ivs->bad_uses++; } It can be proved in an inductive approach that ivs->up_to always equals to use->id at the position. This patch does not change code logic at all, anyway, it passes bootstrap and regtest on x86_64/x86. So is it OK? Thanks, bin 2014-08-27 Bin Cheng <bin.cheng@arm.com> * tree-ssa-loop-ivopts.c (iv_ca_add_use): Delete parameter important_candidates. Consider all important candidates if IVS doesn't give any result. Remove check on ivs->upto. (try_add_cand_for): Call iv_ca_add_use only once.