diff options
| author | Bin Cheng <bin.cheng@arm.com> | 2016-06-17 09:26:05 +0000 |
|---|---|---|
| committer | Bin Cheng <amker@gcc.gnu.org> | 2016-06-17 09:26:05 +0000 |
| commit | d3ee260a2840ee112c110b1b9bcd2c673a9a9ea1 (patch) | |
| tree | 563367258daeb7f327d8757c35e8e7b653b860ee /gcc/tree-ssa-loop-ivopts.c | |
| parent | bd8fb1146e42873785a3d3af65f120aa1888d8db (diff) | |
| download | gcc-d3ee260a2840ee112c110b1b9bcd2c673a9a9ea1.zip gcc-d3ee260a2840ee112c110b1b9bcd2c673a9a9ea1.tar.gz gcc-d3ee260a2840ee112c110b1b9bcd2c673a9a9ea1.tar.bz2 | |
re PR tree-optimization/71347 (Performance drop after r235513 on x86-64 in 32-bit mode.)
PR tree-optimization/71347
* tree-ssa-loop-ivopts.c (determine_group_iv_cost_address): Compute
cost for all uses in group.
PR tree-optimization/71347
* gcc.dg/tree-ssa/pr71347.c: New test.
From-SVN: r237552
Diffstat (limited to 'gcc/tree-ssa-loop-ivopts.c')
| -rw-r--r-- | gcc/tree-ssa-loop-ivopts.c | 31 |
1 files changed, 6 insertions, 25 deletions
diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c index 1e8d637..25b9780 100644 --- a/gcc/tree-ssa-loop-ivopts.c +++ b/gcc/tree-ssa-loop-ivopts.c @@ -5115,7 +5115,7 @@ determine_group_iv_cost_address (struct ivopts_data *data, { unsigned i; bitmap depends_on; - bool can_autoinc, first = true; + bool can_autoinc; iv_inv_expr_ent *inv_expr = NULL; struct iv_use *use = group->vuses[0]; comp_cost sum_cost = no_cost, cost; @@ -5142,30 +5142,11 @@ determine_group_iv_cost_address (struct ivopts_data *data, { struct iv_use *next = group->vuses[i]; - /* Compute cost for the first use with different offset to the main - use and add it afterwards. Costs for these uses could be quite - different. Given below uses in a group: - use 0 : {base + A + offset_0, step} - use 0.1: {base + A + offset_0, step} - use 0.2: {base + A + offset_1, step} - use 0.3: {base + A + offset_2, step} - when we need to compute costs with candidate: - cand 1 : {base + B + offset_0, step} - - The first use with different offset is use 0.2, its cost is larger - than cost of use 0/0.1 because we need to compute: - A - B + offset_1 - offset_0 - rather than: - A - B. */ - if (first && next->addr_offset != use->addr_offset) - { - first = false; - cost = get_computation_cost (data, next, cand, true, - NULL, &can_autoinc, NULL); - /* Remove setup cost. */ - if (!cost.infinite_cost_p ()) - cost -= cost.scratch; - } + /* TODO: We could skip computing cost for sub iv_use when it has the + same cost as the first iv_use, but the cost really depends on the + offset and where the iv_use is. */ + cost = get_computation_cost (data, next, cand, true, + NULL, &can_autoinc, NULL); sum_cost += cost; } set_group_iv_cost (data, group, cand, sum_cost, depends_on, |