From: Pan Li <[email protected]>
The gen_phi_on_cond can only support below control flow for cond
from day 1. Aka:
+------+
| def |
| ... | +-----+
| cond |------>| def |
+------+ | ... |
| +-----+
| |
v |
+-----+ |
| PHI |<----------+
+-----+
Unfortunately, there will be more scenarios of control flow on PHI.
For example as below:
T __attribute__((noinline)) \
sat_s_add_##T##_fmt_3 (T x, T y) \
{ \
T sum; \
bool overflow = __builtin_add_overflow (x, y, &sum); \
return overflow ? x < 0 ? MIN : MAX : sum; \
}
DEF_SAT_S_ADD_FMT_3(int8_t, uint8_t, INT8_MIN, INT8_MAX)
With expanded RTL like below.
3 │
4 │ __attribute__((noinline))
5 │ int8_t sat_s_add_int8_t_fmt_3 (int8_t x, int8_t y)
6 │ {
7 │ signed char _1;
8 │ signed char _2;
9 │ int8_t _3;
10 │ __complex__ signed char _6;
11 │ _Bool _8;
12 │ signed char _9;
13 │ signed char _10;
14 │ signed char _11;
15 │
16 │ ;; basic block 2, loop depth 0
17 │ ;; pred: ENTRY
18 │ _6 = .ADD_OVERFLOW (x_4(D), y_5(D));
19 │ _2 = IMAGPART_EXPR <_6>;
20 │ if (_2 != 0)
21 │ goto <bb 4>; [50.00%]
22 │ else
23 │ goto <bb 3>; [50.00%]
24 │ ;; succ: 4
25 │ ;; 3
26 │
27 │ ;; basic block 3, loop depth 0
28 │ ;; pred: 2
29 │ _1 = REALPART_EXPR <_6>;
30 │ goto <bb 5>; [100.00%]
31 │ ;; succ: 5
32 │
33 │ ;; basic block 4, loop depth 0
34 │ ;; pred: 2
35 │ _8 = x_4(D) < 0;
36 │ _9 = (signed char) _8;
37 │ _10 = -_9;
38 │ _11 = _10 ^ 127;
39 │ ;; succ: 5
40 │
41 │ ;; basic block 5, loop depth 0
42 │ ;; pred: 3
43 │ ;; 4
44 │ # _3 = PHI <_1(3), _11(4)>
45 │ return _3;
46 │ ;; succ: EXIT
47 │
48 │ }
The above code will have below control flow which is not supported by
the gen_phi_on_cond.
+------+
| def |
| ... | +-----+
| cond |------>| def |
+------+ | ... |
| +-----+
| |
v |
+-----+ |
| def | |
| ... | |
+-----+ |
| |
| |
v |
+-----+ |
| PHI |<----------+
+-----+
This patch would like to add support above control flow matching for
the gen_phi_on_cond.
The below testsuites are passed for this patch:
* The rv64gcv fully regression test.
* The x86 bootstrap test.
* The x86 fully regression test.
gcc/ChangeLog:
* gimple-match-head.cc (match_control_flow_graph_case_0): Add
new func impl to match case 0 of cfg.
(match_control_flow_graph_case_1): Ditto but for case 1.
Signed-off-by: Pan Li <[email protected]>
---
gcc/gimple-match-head.cc | 115 +++++++++++++++++++++++++++++++++++++++
1 file changed, 115 insertions(+)
diff --git a/gcc/gimple-match-head.cc b/gcc/gimple-match-head.cc
index 924d3f1e710..c51728ae742 100644
--- a/gcc/gimple-match-head.cc
+++ b/gcc/gimple-match-head.cc
@@ -375,3 +375,118 @@ gimple_bitwise_inverted_equal_p (tree expr1, tree expr2,
bool &wascmp, tree (*va
return true;
return false;
}
+
+/*
+ * Return TRUE if the cfg matches the below layout by the given b2 in
+ * the first argument. Or return FALSE.
+ *
+ * If return TRUE, the output argument b_out will be updated to the b0
+ * block as below example.
+ *
+ * If return FALSE, the output argument b_out will be NULL_BLOCK.
+ *
+ * |
+ * |
+ * v
+ * +------+
+ * | b0: |
+ * | def | +-----+
+ * | ... | | b1: |
+ * | cond |------>| def |
+ * +------+ | ... |
+ * | +-----+
+ * | |
+ * v |
+ * +-----+ |
+ * | b2: | |
+ * | def |<----------+
+ * +-----+
+ */
+static inline bool
+match_control_flow_graph_case_0 (basic_block b2, basic_block *b_out)
+{
+ *b_out = NULL;
+
+ if (EDGE_COUNT (b2->preds) != 2)
+ return false;
+
+ basic_block pred_0 = EDGE_PRED (b2, 0)->src;
+ basic_block pred_1 = EDGE_PRED (b2, 1)->src;
+
+ if (pred_0 == NULL || pred_1 == NULL)
+ return false;
+
+ if (!(EDGE_COUNT (pred_0->succs) == 2 && EDGE_COUNT (pred_1->succs) == 1)
+ && !(EDGE_COUNT (pred_0->succs) == 1 && EDGE_COUNT (pred_1->succs) == 2))
+ return false;
+
+ basic_block b0 = EDGE_COUNT (pred_0->succs) == 2 ? pred_0 : pred_1;
+ basic_block b1 = EDGE_COUNT (pred_0->succs) == 1 ? pred_0 : pred_1;
+
+ if (EDGE_COUNT (b1->preds) != 1 || EDGE_PRED (b1, 0)->src != b0)
+ return false;
+
+ *b_out = b0;
+ return true;
+}
+
+/*
+ * Return TRUE if the cfg matches the below layout by the given b3 in
+ * the first argument. Or return FALSE.
+ *
+ * If return TRUE, the output argument b_out will be updated to the b0
+ * block as below example.
+ *
+ * If return FALSE, the output argument b_out will be NULL.
+ *
+ * |
+ * |
+ * v
+ * +------+
+ * | b0: |
+ * | ... | +-----+
+ * | cond |------>| b2: |
+ * +------+ | ... |
+ * | +-----+
+ * | |
+ * v |
+ * +-----+ |
+ * | b1: | |
+ * | ... | |
+ * +-----+ |
+ * | |
+ * | |
+ * v |
+ * +-----+ |
+ * | b3: |<----------+
+ * | ... |
+ * +-----+
+ */
+static inline bool
+match_control_flow_graph_case_1 (basic_block b3, basic_block *b_out)
+{
+ *b_out = NULL;
+
+ if (EDGE_COUNT (b3->preds) != 2)
+ return false;
+
+ basic_block b1 = EDGE_PRED (b3, 0)->src;
+ basic_block b2 = EDGE_PRED (b3, 1)->src;
+
+ if (b1 == NULL || b2 == NULL)
+ return false;
+
+ if (EDGE_COUNT (b1->succs) != 1
+ || EDGE_COUNT (b1->preds) != 1
+ || EDGE_COUNT (b2->succs) != 1
+ || EDGE_COUNT (b2->preds) != 1)
+ return false;
+
+ basic_block b0 = EDGE_PRED (b1, 0)->src;
+
+ if (EDGE_COUNT (b0->succs) != 2 || EDGE_PRED (b2, 0)->src != b0)
+ return false;
+
+ *b_out = b0;
+ return true;
+}
--
2.43.0
