Hi,
The function gimple_can_duplicate_bb_p currently always returns true.
The presence of can_duplicate_bb_p in tracer.c however suggests that
there are cases when bb's indeed cannot be duplicated.
Move the implementation of can_duplicate_bb_p to gimple_can_duplicate_bb_p.
Bootstrapped and reg-tested on x86_64-linux.
Build x86_64-linux with nvptx accelerator and tested libgomp.
No issues found.
As corner-case check, bootstrapped and reg-tested a patch that makes
gimple_can_duplicate_bb_p always return false, resulting in
PR97333 - "[gimple_can_duplicate_bb_p == false, tree-ssa-threadupdate]
ICE in duplicate_block, at cfghooks.c:1093".
Any comments?
Thanks,
- Tom
[gimple] Move can_duplicate_bb_p to gimple_can_duplicate_bb_p
gcc/ChangeLog:
2020-10-09 Tom de Vries <tdevr...@suse.de>
* tracer.c (cached_can_duplicate_bb_p): Use can_duplicate_block_p
instead of can_duplicate_bb_p.
(can_duplicate_insn_p, can_duplicate_bb_no_insn_iter_p): Move ...
* tree-cfg.c: ... here.
* tracer.c (can_duplicate_bb_p): Move ...
* tree-cfg.c (gimple_can_duplicate_bb_p): here.
* tree-cfg.h (can_duplicate_insn_p, can_duplicate_bb_no_insn_iter_p):
Declare.
---
gcc/tracer.c | 61 +---------------------------------------------------------
gcc/tree-cfg.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++-
gcc/tree-cfg.h | 2 ++
3 files changed, 56 insertions(+), 61 deletions(-)
diff --git a/gcc/tracer.c b/gcc/tracer.c
index e1c2b9527e5..16b46c65b14 100644
--- a/gcc/tracer.c
+++ b/gcc/tracer.c
@@ -84,65 +84,6 @@ bb_seen_p (basic_block bb)
return bitmap_bit_p (bb_seen, bb->index);
}
-/* Return true if gimple stmt G can be duplicated. */
-static bool
-can_duplicate_insn_p (gimple *g)
-{
- /* An IFN_GOMP_SIMT_ENTER_ALLOC/IFN_GOMP_SIMT_EXIT call must be
- duplicated as part of its group, or not at all.
- The IFN_GOMP_SIMT_VOTE_ANY and IFN_GOMP_SIMT_XCHG_* are part of such a
- group, so the same holds there. */
- if (is_gimple_call (g)
- && (gimple_call_internal_p (g, IFN_GOMP_SIMT_ENTER_ALLOC)
- || gimple_call_internal_p (g, IFN_GOMP_SIMT_EXIT)
- || gimple_call_internal_p (g, IFN_GOMP_SIMT_VOTE_ANY)
- || gimple_call_internal_p (g, IFN_GOMP_SIMT_XCHG_BFLY)
- || gimple_call_internal_p (g, IFN_GOMP_SIMT_XCHG_IDX)))
- return false;
-
- return true;
-}
-
-/* Return true if BB can be duplicated. Avoid iterating over the insns. */
-static bool
-can_duplicate_bb_no_insn_iter_p (const_basic_block bb)
-{
- if (bb->index < NUM_FIXED_BLOCKS)
- return false;
-
- if (gimple *g = last_stmt (CONST_CAST_BB (bb)))
- {
- /* A transaction is a single entry multiple exit region. It
- must be duplicated in its entirety or not at all. */
- if (gimple_code (g) == GIMPLE_TRANSACTION)
- return false;
-
- /* An IFN_UNIQUE call must be duplicated as part of its group,
- or not at all. */
- if (is_gimple_call (g)
- && gimple_call_internal_p (g)
- && gimple_call_internal_unique_p (g))
- return false;
- }
-
- return true;
-}
-
-/* Return true if BB can be duplicated. */
-static bool
-can_duplicate_bb_p (const_basic_block bb)
-{
- if (!can_duplicate_bb_no_insn_iter_p (bb))
- return false;
-
- for (gimple_stmt_iterator gsi = gsi_start_bb (CONST_CAST_BB (bb));
- !gsi_end_p (gsi); gsi_next (&gsi))
- if (!can_duplicate_insn_p (gsi_stmt (gsi)))
- return false;
-
- return true;
-}
-
static sbitmap can_duplicate_bb;
/* Cache VAL as value of can_duplicate_bb_p for BB. */
@@ -167,7 +108,7 @@ cached_can_duplicate_bb_p (const_basic_block bb)
return false;
}
- return can_duplicate_bb_p (bb);
+ return can_duplicate_block_p (bb);
}
/* Return true if we should ignore the basic block for purposes of tracing. */
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index 5caf3b62d69..a5677859ffc 100644
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -6208,11 +6208,63 @@ gimple_split_block_before_cond_jump (basic_block bb)
}
+/* Return true if gimple stmt G can be duplicated. */
+bool
+can_duplicate_insn_p (gimple *g)
+{
+ /* An IFN_GOMP_SIMT_ENTER_ALLOC/IFN_GOMP_SIMT_EXIT call must be
+ duplicated as part of its group, or not at all.
+ The IFN_GOMP_SIMT_VOTE_ANY and IFN_GOMP_SIMT_XCHG_* are part of such a
+ group, so the same holds there. */
+ if (is_gimple_call (g)
+ && (gimple_call_internal_p (g, IFN_GOMP_SIMT_ENTER_ALLOC)
+ || gimple_call_internal_p (g, IFN_GOMP_SIMT_EXIT)
+ || gimple_call_internal_p (g, IFN_GOMP_SIMT_VOTE_ANY)
+ || gimple_call_internal_p (g, IFN_GOMP_SIMT_XCHG_BFLY)
+ || gimple_call_internal_p (g, IFN_GOMP_SIMT_XCHG_IDX)))
+ return false;
+
+ return true;
+}
+
+/* Return true if BB can be duplicated. Avoid iterating over the insns. */
+bool
+can_duplicate_bb_no_insn_iter_p (const_basic_block bb)
+{
+ if (bb->index < NUM_FIXED_BLOCKS)
+ return false;
+
+ if (gimple *g = last_stmt (CONST_CAST_BB (bb)))
+ {
+ /* A transaction is a single entry multiple exit region. It
+ must be duplicated in its entirety or not at all. */
+ if (gimple_code (g) == GIMPLE_TRANSACTION)
+ return false;
+
+ /* An IFN_UNIQUE call must be duplicated as part of its group,
+ or not at all. */
+ if (is_gimple_call (g)
+ && gimple_call_internal_p (g)
+ && gimple_call_internal_unique_p (g))
+ return false;
+ }
+
+ return true;
+}
+
/* Return true if basic_block can be duplicated. */
static bool
-gimple_can_duplicate_bb_p (const_basic_block bb ATTRIBUTE_UNUSED)
+gimple_can_duplicate_bb_p (const_basic_block bb)
{
+ if (!can_duplicate_bb_no_insn_iter_p (bb))
+ return false;
+
+ for (gimple_stmt_iterator gsi = gsi_start_bb (CONST_CAST_BB (bb));
+ !gsi_end_p (gsi); gsi_next (&gsi))
+ if (!can_duplicate_insn_p (gsi_stmt (gsi)))
+ return false;
+
return true;
}
diff --git a/gcc/tree-cfg.h b/gcc/tree-cfg.h
index beb4997a61c..9b270615321 100644
--- a/gcc/tree-cfg.h
+++ b/gcc/tree-cfg.h
@@ -117,6 +117,8 @@ extern basic_block gimple_switch_label_bb (function *,
gswitch *, unsigned);
extern basic_block gimple_switch_default_bb (function *, gswitch *);
extern edge gimple_switch_edge (function *, gswitch *, unsigned);
extern edge gimple_switch_default_edge (function *, gswitch *);
+extern bool can_duplicate_insn_p (gimple *);
+extern bool can_duplicate_bb_no_insn_iter_p (const_basic_block);
/* Return true if the LHS of a call should be removed. */
