Add params for jump-table expansion params (PR middle-end/90340).

2019-05-10  Martin Liska  <mliska@suse.cz>

	PR middle-end/90340
	* doc/invoke.texi: New params.
	* params.def (PARAM_JUMP_TABLE_MAX_GROWTH_RATIO_FOR_SIZE): New.
	(PARAM_JUMP_TABLE_MAX_GROWTH_RATIO_FOR_SPEED): Likewise.
	* tree-switch-conversion.c (jump_table_cluster::can_be_handled):
	Use it.
	* tree-switch-conversion.h (struct jump_table_cluster):
	Likewise.
2019-05-10  Martin Liska  <mliska@suse.cz>

	PR middle-end/90340
	* gcc.dg/tree-ssa/pr90340-2.c: New test.
	* gcc.dg/tree-ssa/pr90340.c: New test.

From-SVN: r271053

gcc/ChangeLog

+2019-05-10  Martin Liska  <mliska@suse.cz>
+
+	PR middle-end/90340
+	* doc/invoke.texi: New params.
+	* params.def (PARAM_JUMP_TABLE_MAX_GROWTH_RATIO_FOR_SIZE): New.
+	(PARAM_JUMP_TABLE_MAX_GROWTH_RATIO_FOR_SPEED): Likewise.
+	* tree-switch-conversion.c (jump_table_cluster::can_be_handled):
+	Use it.
+	* tree-switch-conversion.h (struct jump_table_cluster):
+	Likewise.
+
 2019-05-09  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	* combine.c (combine_simplify_rtx): Don't make IF_THEN_ELSE RTL.

gcc/doc/invoke.texi

@@ -11889,6 +11889,16 @@ The smallest number of different values for which it is best to use a
 jump-table instead of a tree of conditional branches.  If the value is
 0, use the default for the machine.
 
+@item jump-table-max-growth-ratio-for-size
+The maximum code size growth ratio when expanding
+into a jump table (in percent).  The parameter is used when
+optimizing for size.
+
+@item jump-table-max-growth-ratio-for-speed
+The maximum code size growth ratio when expanding
+into a jump table (in percent).  The parameter is used when
+optimizing for speed.
+
 @item tree-reassoc-width
 Set the maximum number of instructions executed in parallel in
 reassociated tree. This parameter overrides target dependent

gcc/params.def

@@ -1175,6 +1175,20 @@ DEFPARAM (PARAM_CASE_VALUES_THRESHOLD,
 	  "if 0, use the default for the machine.",
           0, 0, 0)
 
+DEFPARAM (PARAM_JUMP_TABLE_MAX_GROWTH_RATIO_FOR_SIZE,
+	  "jump-table-max-growth-ratio-for-size",
+	  "The maximum code size growth ratio when expanding "
+	  "into a jump table (in percent).  The parameter is used when "
+	  "optimizing for size.",
+	  300, 0, 0)
+
+DEFPARAM (PARAM_JUMP_TABLE_MAX_GROWTH_RATIO_FOR_SPEED,
+	  "jump-table-max-growth-ratio-for-speed",
+	  "The maximum code size growth ratio when expanding "
+	  "into a jump table (in percent).  The parameter is used when "
+	  "optimizing for speed.",
+	  800, 0, 0)
+
 /* Data race flags for C++0x memory model compliance.  */
 DEFPARAM (PARAM_ALLOW_STORE_DATA_RACES,
 	  "allow-store-data-races",

gcc/testsuite/ChangeLog

+2019-05-10  Martin Liska  <mliska@suse.cz>
+
+	PR middle-end/90340
+	* gcc.dg/tree-ssa/pr90340-2.c: New test.
+	* gcc.dg/tree-ssa/pr90340.c: New test.
+
 2019-05-09  Cherry Zhang  <cherryyz@google.com>
 
 	* go.dg/mapstring.go: New test.

gcc/testsuite/gcc.dg/tree-ssa/pr90340-2.c

+/* { dg-do compile { target { { x86_64-*-* aarch64-*-* ia64-*-* powerpc64-*-* } && lp64 } } } */
+/* { dg-options "-Os --param jump-table-max-growth-ratio-for-size=200 -fdump-tree-switchlower1" } */
+
+int a;
+
+int foo(char c) {
+  switch (c) {
+  case 'c':
+    return a;
+  case 's':
+    return 3;
+  case 'n':
+    return 1;
+  case '%':
+    return -2;
+  case 'o':
+    return a + 2;
+    break;
+  case 'X':
+  case 'x':
+    return 2222;
+  case 'd':
+  case 'i':
+  case 'u':
+    return 3333;
+  default:
+    return 0;
+  }
+}
+
+/* { dg-final { scan-tree-dump ";; GIMPLE switch case clusters: 37 88 99 100 105 110 111 115 117 120" "switchlower1" } } */

gcc/testsuite/gcc.dg/tree-ssa/pr90340.c

+/* { dg-do compile { target { { x86_64-*-* aarch64-*-* ia64-*-* powerpc64-*-* } && lp64 } } } */
+/* { dg-options "-Os -fdump-tree-switchlower1" } */
+
+int a;
+
+int foo(char c) {
+  switch (c) {
+  case 'c':
+    return a;
+  case 's':
+    return 3;
+  case 'n':
+    return 1;
+  case '%':
+    return -2;
+  case 'o':
+    return a + 2;
+    break;
+  case 'X':
+  case 'x':
+    return 2222;
+  case 'd':
+  case 'i':
+  case 'u':
+    return 3333;
+  default:
+    return 0;
+  }
+}
+
+/* { dg-final { scan-tree-dump ";; GIMPLE switch case clusters: 37 88 JT:99-120" "switchlower1" } } */

gcc/tree-switch-conversion.c

@@ -1268,7 +1268,9 @@ jump_table_cluster::can_be_handled (const vec<cluster *> &clusters,
     return true;
 
   unsigned HOST_WIDE_INT max_ratio
-    = optimize_insn_for_size_p () ? max_ratio_for_size : max_ratio_for_speed;
+    = (optimize_insn_for_size_p ()
+       ? PARAM_VALUE (PARAM_JUMP_TABLE_MAX_GROWTH_RATIO_FOR_SIZE)
+       : PARAM_VALUE (PARAM_JUMP_TABLE_MAX_GROWTH_RATIO_FOR_SPEED));
   unsigned HOST_WIDE_INT range = get_range (clusters[start]->get_low (),
 					    clusters[end]->get_high ());
   /* Check overflow.  */
@@ -1282,7 +1284,7 @@ jump_table_cluster::can_be_handled (const vec<cluster *> &clusters,
       comparison_count += sc->m_range_p ? 2 : 1;
     }
 
-  return range <= max_ratio * comparison_count;
+  return 100 * range <= max_ratio * comparison_count;
 }
 
 /* Return true if cluster starting at START and ending at END (inclusive)
@@ -1299,11 +1301,6 @@ jump_table_cluster::is_beneficial (const vec<cluster *> &,
   return end - start + 1 >= case_values_threshold ();
 }
 
-/* Definition of jump_table_cluster constants.  */
-
-const unsigned HOST_WIDE_INT jump_table_cluster::max_ratio_for_size;
-const unsigned HOST_WIDE_INT jump_table_cluster::max_ratio_for_speed;
-
 /* Find bit tests of given CLUSTERS, where all members of the vector
    are of type simple_cluster.  New clusters are returned.  */
 

gcc/tree-switch-conversion.h

@@ -269,12 +269,6 @@ struct jump_table_cluster: public group_cluster
 
   /* Return whether jump table expansion is allowed.  */
   static bool is_enabled (void);
-
-  /* Max growth ratio for code that is optimized for size.  */
-  static const unsigned HOST_WIDE_INT max_ratio_for_size = 3;
-
-  /* Max growth ratio for code that is optimized for speed.  */
-  static const unsigned HOST_WIDE_INT max_ratio_for_speed = 8;
 };
 
 /* A GIMPLE switch statement can be expanded to a short sequence of bit-wise