From e144a2b3066ecad2a7c934b1cd437d2afad0018f Mon Sep 17 00:00:00 2001
From: Richard Biener <rguenther@suse.de>
Date: Fri, 24 Aug 2018 11:17:16 +0000
Subject: cfg.h (struct control_flow_graph): Add edge_flags_allocated and
 bb_flags_allocated members.

2018-08-24  Richard Biener  <rguenther@suse.de>

	* cfg.h (struct control_flow_graph): Add edge_flags_allocated and
	bb_flags_allocated members.
	(auto_flag): New RAII class for allocating flags.
	(auto_edge_flag): New RAII class for allocating edge flags.
	(auto_bb_flag): New RAII class for allocating bb flags.
	* cfgloop.c (verify_loop_structure): Allocate temporary edge
	flag dynamically.
	* cfganal.c (dfs_enumerate_from): Remove use of visited sbitmap
	in favor of temporarily allocated BB flag.
	* hsa-brig.c: Re-order includes.
	* hsa-dump.c: Likewise.
	* hsa-regalloc.c: Likewise.
	* print-rtl.c: Likewise.
	* profile-count.c: Likewise.

From-SVN: r263830
---
 gcc/cfg.h | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

(limited to 'gcc/cfg.h')

diff --git a/gcc/cfg.h b/gcc/cfg.h
index 0953456..9fff135 100644
--- a/gcc/cfg.h
+++ b/gcc/cfg.h
@@ -74,6 +74,10 @@ struct GTY(()) control_flow_graph {
 
   /* Maximal count of BB in function.  */
   profile_count count_max;
+
+  /* Dynamically allocated edge/bb flags.  */
+  int edge_flags_allocated;
+  int bb_flags_allocated;
 };
 
 
@@ -121,4 +125,60 @@ extern basic_block get_bb_copy (basic_block);
 void set_loop_copy (struct loop *, struct loop *);
 struct loop *get_loop_copy (struct loop *);
 
+/* Generic RAII class to allocate a bit from storage of integer type T.
+   The allocated bit is accessible as mask with the single bit set
+   via the conversion operator to T.  */
+
+template <class T>
+class auto_flag
+{
+public:
+  /* static assert T is integer type of max HOST_WIDE_INT precision.  */
+  auto_flag (T *sptr)
+    {
+      m_sptr = sptr;
+      int free_bit = ffs_hwi (~*sptr);
+      /* If there are no unset bits... */
+      if (free_bit == 0)
+	gcc_unreachable ();
+      m_flag = HOST_WIDE_INT_1U << (free_bit - 1);
+      /* ...or if T is signed and thus the complement is sign-extended,
+         check if we ran out of bits.  We could spare us this bit
+	 if we could use C++11 std::make_unsigned<T>::type to pass
+	 ~*sptr to ffs_hwi.  */
+      if (m_flag == 0)
+	gcc_unreachable ();
+      gcc_checking_assert ((*sptr & m_flag) == 0);
+      *sptr |= m_flag;
+    }
+  ~auto_flag ()
+    {
+      gcc_checking_assert ((*m_sptr & m_flag) == m_flag);
+      *m_sptr &= ~m_flag;
+    }
+  operator T () const { return m_flag; }
+private:
+  T *m_sptr;
+  T m_flag;
+};
+
+/* RAII class to allocate an edge flag for temporary use.  You have
+   to clear the flag from all edges when you are finished using it.  */
+
+class auto_edge_flag : public auto_flag<int>
+{
+public:
+  auto_edge_flag (function *fun)
+    : auto_flag (&fun->cfg->edge_flags_allocated) {}
+};
+
+/* RAII class to allocate a bb flag for temporary use.  You have
+   to clear the flag from all edges when you are finished using it.  */
+class auto_bb_flag : public auto_flag<int>
+{
+public:
+  auto_bb_flag (function *fun)
+    : auto_flag (&fun->cfg->bb_flags_allocated) {}
+};
+
 #endif /* GCC_CFG_H */
-- 
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