[COMMITTED] Remove TDF_THREADING flag in favor of param.

diff --git a/gcc/dumpfile.c b/gcc/dumpfile.c
index e6ead5debe5..8169daf7f59 100644
--- a/gcc/dumpfile.c
+++ b/gcc/dumpfile.c
@@ -145,7 +145,6 @@  static const kv_pair<dump_flags_t> dump_options[] =
   {"missed", MSG_MISSED_OPTIMIZATION},
   {"note", MSG_NOTE},
   {"optall", MSG_ALL_KINDS},
-  {"threading", TDF_THREADING},
   {"all", dump_flags_t (TDF_ALL_VALUES
 			& ~(TDF_RAW | TDF_SLIM | TDF_LINENO | TDF_GRAPH
 			    | TDF_STMTADDR | TDF_RHS_ONLY | TDF_NOUID
diff --git a/gcc/dumpfile.h b/gcc/dumpfile.h
index 76226753845..2487ae243c6 100644
--- a/gcc/dumpfile.h
+++ b/gcc/dumpfile.h
@@ -146,20 +146,17 @@  enum dump_flag : uint32_t
   /* Dump folding details.  */
   TDF_FOLDING = (1 << 21),
 
-  /* Dumping for range path solver.  */
-  TDF_THREADING = (1 << 22),
-
   /* MSG_* flags for expressing the kinds of message to
      be emitted by -fopt-info.  */
 
   /* -fopt-info optimized sources.  */
-  MSG_OPTIMIZED_LOCATIONS = (1 << 23),
+  MSG_OPTIMIZED_LOCATIONS = (1 << 22),
 
   /* Missed opportunities.  */
-  MSG_MISSED_OPTIMIZATION = (1 << 24),
+  MSG_MISSED_OPTIMIZATION = (1 << 23),
 
   /* General optimization info.  */
-  MSG_NOTE = (1 << 25),
+  MSG_NOTE = (1 << 24),
 
   /* Mask for selecting MSG_-kind flags.  */
   MSG_ALL_KINDS = (MSG_OPTIMIZED_LOCATIONS
@@ -178,16 +175,16 @@  enum dump_flag : uint32_t
      sub-option of -fopt-info to show the internal messages.  */
 
   /* Implicitly supplied for messages at the top-level dump scope.  */
-  MSG_PRIORITY_USER_FACING = (1 << 26),
+  MSG_PRIORITY_USER_FACING = (1 << 25),
 
   /* Implicitly supplied for messages within nested dump scopes.  */
-  MSG_PRIORITY_INTERNALS = (1 << 27),
+  MSG_PRIORITY_INTERNALS = (1 << 26),
 
   /* Supplied when an opt_problem generated in a nested scope is re-emitted
      at the top-level.   We want to default to showing these in -fopt-info
      output, but to *not* show them in dump files, as the message would be
      shown twice, messing up "scan-tree-dump-times" in DejaGnu tests.  */
-  MSG_PRIORITY_REEMITTED = (1 << 28),
+  MSG_PRIORITY_REEMITTED = (1 << 27),
 
   /* Mask for selecting MSG_PRIORITY_* flags.  */
   MSG_ALL_PRIORITIES = (MSG_PRIORITY_USER_FACING
@@ -195,16 +192,16 @@  enum dump_flag : uint32_t
 			| MSG_PRIORITY_REEMITTED),
 
   /* All -fdump- flags.  */
-  TDF_ALL_VALUES = (1 << 29) - 1,
+  TDF_ALL_VALUES = (1 << 28) - 1,
 
   /* Dumping for -fcompare-debug.  */
-  TDF_COMPARE_DEBUG = (1 << 29),
+  TDF_COMPARE_DEBUG = (1 << 28),
 
   /* Dump a GIMPLE value which means wrapping certain things with _Literal.  */
-  TDF_GIMPLE_VAL = (1 << 30),
+  TDF_GIMPLE_VAL = (1 << 29),
 
   /* For error.  */
-  TDF_ERROR = ((uint32_t)1 << 31),
+  TDF_ERROR = ((uint32_t)1 << 30),
 };
 
 /* Dump flags type.  */
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index 459e3e07016..cfd2a5f6f50 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -462,6 +462,13 @@  enum ranger_debug
 		      | RANGER_DEBUG_TRACE)
 };
 
+/* Jump threader verbose dumps.  */
+enum threader_debug
+{
+  THREADER_DEBUG_NONE = 0,
+  THREADER_DEBUG_ALL = 1
+};
+
 /* EVRP mode.  */
 enum evrp_mode
 {
diff --git a/gcc/gimple-range-path.cc b/gcc/gimple-range-path.cc
index 9d3fe89185e..52de10369f3 100644
--- a/gcc/gimple-range-path.cc
+++ b/gcc/gimple-range-path.cc
@@ -34,7 +34,7 @@  along with GCC; see the file COPYING3.  If not see
 #include "gimple-iterator.h"
 
 // Internal construct to help facilitate debugging of solver.
-#define DEBUG_SOLVER (dump_file && dump_flags & TDF_THREADING)
+#define DEBUG_SOLVER (dump_file && (param_threader_debug == THREADER_DEBUG_ALL))
 
 path_range_query::path_range_query (gimple_ranger &ranger, bool resolve)
   : m_ranger (ranger)
diff --git a/gcc/params.opt b/gcc/params.opt
index 4b409d55a2d..e725c99e5e4 100644
--- a/gcc/params.opt
+++ b/gcc/params.opt
@@ -1047,6 +1047,19 @@  Maximum number of escape points tracked by modref per SSA-name.
 Common Joined UInteger Var(param_modref_max_adjustments) Init(8) IntegerRange(0, 254) Param Optimization
 Maximum number of times a given range is adjusted during the dataflow.
 
+-param=threader-debug=
+Common Joined Var(param_threader_debug) Enum(threader_debug) Init(THREADER_DEBUG_NONE) Param Optimization
+--param=threader-debug=[none|all] Enables verbose dumping of the threader solver.
+
+Enum
+Name(threader_debug) Type(enum threader_debug) UnknownError(unknown threader debug mode %qs)
+
+EnumValue
+Enum(threader_debug) String(none) Value(THREADER_DEBUG_NONE)
+
+EnumValue
+Enum(threader_debug) String(all) Value(THREADER_DEBUG_ALL)
+
 -param=tm-max-aggregate-size=
 Common Joined UInteger Var(param_tm_max_aggregate_size) Init(9) Param Optimization
 Size in bytes after which thread-local aggregates should be instrumented with the logging functions instead of save/restore pairs.