1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
https://gcc.gnu.org/PR111860
https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;h=9ed6b22eb4188c57bb3f5cdba5a7effa95395186
From 9ed6b22eb4188c57bb3f5cdba5a7effa95395186 Mon Sep 17 00:00:00 2001
From: Tamar Christina <tamar.christina@arm.com>
Date: Mon, 23 Oct 2023 14:07:20 +0100
Subject: [PATCH] middle-end: don't keep .MEM guard nodes for PHI nodes who
dominate loop [PR111860]
The previous patch tried to remove PHI nodes that dominated the first loop,
however the correct fix is to only remove .MEM nodes.
This patch thus makes the condition a bit stricter and only tries to remove
MEM phi nodes.
I couldn't figure out a way to easily determine if a particular PHI is vUSE
related, so the patch does:
1. check if the definition is a vDEF and not defined in main loop.
2. check if the definition is a PHI and not defined in main loop.
3. check if the definition is a default definition.
For no 2 and 3 we may misidentify the PHI, in both cases the value is defined
outside of the loop version block which also makes it ok to remove.
gcc/ChangeLog:
PR tree-optimization/111860
* tree-vect-loop-manip.cc (slpeel_tree_duplicate_loop_to_edge_cfg):
Drop .MEM nodes only.
gcc/testsuite/ChangeLog:
PR tree-optimization/111860
* gcc.dg/vect/pr111860-2.c: New test.
* gcc.dg/vect/pr111860-3.c: New test.
---
gcc/testsuite/gcc.dg/vect/pr111860-2.c | 17 +++++++++++++++++
gcc/testsuite/gcc.dg/vect/pr111860-3.c | 17 +++++++++++++++++
gcc/tree-vect-loop-manip.cc | 21 ++++++++++++++++++++-
3 files changed, 54 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/vect/pr111860-2.c
create mode 100644 gcc/testsuite/gcc.dg/vect/pr111860-3.c
diff --git a/gcc/testsuite/gcc.dg/vect/pr111860-2.c b/gcc/testsuite/gcc.dg/vect/pr111860-2.c
new file mode 100644
index 000000000000..07f64ffb5318
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr111860-2.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fno-tree-sink -ftree-vectorize" } */
+int buffer_ctrl_ctx_0, buffer_ctrl_p1, buffer_ctrl_cmd;
+
+int
+buffer_ctrl (long ret, int i)
+{
+ switch (buffer_ctrl_cmd)
+ {
+ case 1:
+ buffer_ctrl_ctx_0 = 0;
+ for (; i; i++)
+ if (buffer_ctrl_p1)
+ ret++;
+ }
+ return ret;
+}
diff --git a/gcc/testsuite/gcc.dg/vect/pr111860-3.c b/gcc/testsuite/gcc.dg/vect/pr111860-3.c
new file mode 100644
index 000000000000..07f64ffb5318
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr111860-3.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fno-tree-sink -ftree-vectorize" } */
+int buffer_ctrl_ctx_0, buffer_ctrl_p1, buffer_ctrl_cmd;
+
+int
+buffer_ctrl (long ret, int i)
+{
+ switch (buffer_ctrl_cmd)
+ {
+ case 1:
+ buffer_ctrl_ctx_0 = 0;
+ for (; i; i++)
+ if (buffer_ctrl_p1)
+ ret++;
+ }
+ return ret;
+}
diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc
index d67c94700144..43ca985c53ce 100644
--- a/gcc/tree-vect-loop-manip.cc
+++ b/gcc/tree-vect-loop-manip.cc
@@ -1626,12 +1626,31 @@ slpeel_tree_duplicate_loop_to_edge_cfg (class loop *loop, edge loop_exit,
edge temp_e = redirect_edge_and_branch (exit, new_preheader);
flush_pending_stmts (temp_e);
}
-
/* Record the new SSA names in the cache so that we can skip materializing
them again when we fill in the rest of the LCSSA variables. */
for (auto phi : new_phis)
{
tree new_arg = gimple_phi_arg (phi, 0)->def;
+
+ if (!SSA_VAR_P (new_arg))
+ continue;
+ /* If the PHI MEM node dominates the loop then we shouldn't create
+ a new LC-SSSA PHI for it in the intermediate block. */
+ /* A MEM phi that consitutes a new DEF for the vUSE chain can either
+ be a .VDEF or a PHI that operates on MEM. And said definition
+ must not be inside the main loop. Or we must be a parameter.
+ In the last two cases we may remove a non-MEM PHI node, but since
+ they dominate both loops the removal is unlikely to cause trouble
+ as the exits must already be using them. */
+ if (virtual_operand_p (new_arg)
+ && (SSA_NAME_IS_DEFAULT_DEF (new_arg)
+ || !flow_bb_inside_loop_p (loop,
+ gimple_bb (SSA_NAME_DEF_STMT (new_arg)))))
+ {
+ auto gsi = gsi_for_stmt (phi);
+ remove_phi_node (&gsi, true);
+ continue;
+ }
new_phi_args.put (new_arg, gimple_phi_result (phi));
if (TREE_CODE (new_arg) != SSA_NAME)
--
2.39.3
|
