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* [RFC][gimple] Move can_duplicate_bb_p to gimple_can_duplicate_bb_p
@ 2020-10-09 13:36 Tom de Vries
  2020-10-12  7:15 ` Richard Biener
  0 siblings, 1 reply; 6+ messages in thread
From: Tom de Vries @ 2020-10-09 13:36 UTC (permalink / raw)
  To: gcc-patches; +Cc: Richard Biener

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  <tdevries@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.  */
 

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2020-10-14 12:35 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-10-09 13:36 [RFC][gimple] Move can_duplicate_bb_p to gimple_can_duplicate_bb_p Tom de Vries
2020-10-12  7:15 ` Richard Biener
2020-10-13 15:36   ` Tom de Vries
2020-10-14  6:15     ` Richard Biener
2020-10-14 10:05       ` Tom de Vries
2020-10-14 12:35         ` Richard Biener

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