loop split condition is moved between loop1 and loop2, the split bb's
count and probability should also be duplicated instead of (100% vs INV),
secondly, the original loop1 and loop2 count need be propotional from the
original loop.
Regression tested pass, OK for master?
diff base/loop-cond-split-1.c.151t.lsplit
patched/loop-cond-split-1.c.151t.lsplit:
...
int prephitmp_16;
int prephitmp_25;
<bb 2> [local count: 118111600]:
if (n_7(D) > 0)
goto <bb 4>; [89.00%]
else
goto <bb 3>; [11.00%]
<bb 3> [local count: 118111600]:
return;
<bb 4> [local count: 105119324]:
pretmp_3 = ga;
- <bb 5> [local count: 955630225]:
+ <bb 5> [local count: 315357973]:
# i_13 = PHI <i_10(20), 0(4)>
# prephitmp_12 = PHI <prephitmp_5(20), pretmp_3(4)>
if (prephitmp_12 != 0)
goto <bb 6>; [33.00%]
else
goto <bb 7>; [67.00%]
- <bb 6> [local count: 315357972]:
+ <bb 6> [local count: 104068130]:
_2 = do_something ();
ga = _2;
- <bb 7> [local count: 955630225]:
+ <bb 7> [local count: 315357973]:
# prephitmp_5 = PHI <prephitmp_12(5), _2(6)>
i_10 = inc (i_13);
if (n_7(D) > i_10)
goto <bb 21>; [89.00%]
else
goto <bb 11>; [11.00%]
<bb 11> [local count: 105119324]:
goto <bb 3>; [100.00%]
- <bb 21> [local count: 850510901]:
+ <bb 21> [local count: 280668596]:
if (prephitmp_12 != 0)
- goto <bb 20>; [100.00%]
+ goto <bb 20>; [33.00%]
else
- goto <bb 19>; [INV]
+ goto <bb 19>; [67.00%]
- <bb 20> [local count: 850510901]:
+ <bb 20> [local count: 280668596]:
goto <bb 5>; [100.00%]
- <bb 19> [count: 0]:
+ <bb 19> [local count: 70429947]:
# i_23 = PHI <i_10(21)>
# prephitmp_25 = PHI <prephitmp_5(21)>
- <bb 12> [local count: 955630225]:
+ <bb 12> [local count: 640272252]:
# i_15 = PHI <i_23(19), i_22(16)>
# prephitmp_16 = PHI <prephitmp_25(19), prephitmp_16(16)>
i_22 = inc (i_15);
if (n_7(D) > i_22)
goto <bb 16>; [89.00%]
else
goto <bb 11>; [11.00%]
- <bb 16> [local count: 850510901]:
+ <bb 16> [local count: 569842305]:
goto <bb 12>; [100.00%]
}
gcc/ChangeLog:
* tree-ssa-loop-split.c (split_loop): Fix incorrect probability.
(do_split_loop_on_cond): Likewise.
---
gcc/tree-ssa-loop-split.c | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
diff --git a/gcc/tree-ssa-loop-split.c b/gcc/tree-ssa-loop-split.c
index 3f6ad046623..d30782888f3 100644
--- a/gcc/tree-ssa-loop-split.c
+++ b/gcc/tree-ssa-loop-split.c
@@ -575,7 +575,11 @@ split_loop (class loop *loop1)
stmts2);
tree cond = build2 (guard_code, boolean_type_node, guard_init, border);
if (!initial_true)
- cond = fold_build1 (TRUTH_NOT_EXPR, boolean_type_node, cond);
+ cond = fold_build1 (TRUTH_NOT_EXPR, boolean_type_node, cond);
+
+ edge true_edge = EDGE_SUCC (bbs[i], 0)->flags & EDGE_TRUE_VALUE
+ ? EDGE_SUCC (bbs[i], 0)
+ : EDGE_SUCC (bbs[i], 1);
/* Now version the loop, placing loop2 after loop1 connecting
them, and fix up SSA form for that. */
@@ -583,10 +587,10 @@ split_loop (class loop *loop1)
basic_block cond_bb;
class loop *loop2 = loop_version (loop1, cond, &cond_bb,
- profile_probability::always (),
- profile_probability::always (),
- profile_probability::always (),
- profile_probability::always (),
+ true_edge->probability,
+ true_edge->probability.invert (),
+ true_edge->probability,
+ true_edge->probability.invert (),
true);
gcc_assert (loop2);
@@ -1486,10 +1490,10 @@ do_split_loop_on_cond (struct loop *loop1, edge
invar_branch)
initialize_original_copy_tables ();
struct loop *loop2 = loop_version (loop1, boolean_true_node, NULL,
- profile_probability::always (),
- profile_probability::never (),
- profile_probability::always (),
- profile_probability::always (),
+ invar_branch->probability.invert (),
+ invar_branch->probability,
+ invar_branch->probability.invert (),
+ invar_branch->probability,
true);
if (!loop2)
{
@@ -1530,6 +1534,9 @@ do_split_loop_on_cond (struct loop *loop1, edge
invar_branch)
to_loop1->flags |= true_invar ? EDGE_FALSE_VALUE : EDGE_TRUE_VALUE;
to_loop2->flags |= true_invar ? EDGE_TRUE_VALUE : EDGE_FALSE_VALUE;
+ to_loop1->probability = invar_branch->probability.invert ();
+ to_loop2->probability = invar_branch->probability;
+
/* Due to introduction of a control flow edge from loop1 latch to loop2
pre-header, we should update PHIs in loop2 to reflect this connection
between loop1 and loop2. */
--
2.27.0.90.geebb51ba8c
