move layer into meta-oe in preparation for future splits

As per TSC decision

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>

1 files changed, 811 insertions, 0 deletions

diff --git a/meta-oe/recipes-devtools/gcc/gcc-4.5/linaro/gcc-4.5-linaro-r99468.patch b/meta-oe/recipes-devtools/gcc/gcc-4.5/linaro/gcc-4.5-linaro-r99468.patch
new file mode 100644
index 000000000..cf22aaf16
--- /dev/null
+++ b/meta-oe/recipes-devtools/gcc/gcc-4.5/linaro/gcc-4.5-linaro-r99468.patch
@@ -0,0 +1,811 @@
+2010-12-13  Tom de Vries  <tom@codesourcery.com>
+
+        gcc/
+        * tree-if-switch-conversion.c: New pass.
+        * tree-pass.h (pass_if_to_switch): Declare.
+        * common.opt (ftree-if-to-switch-conversion): New switch.
+        * opts.c (decode_options): Set flag_tree_if_to_switch_conversion at -O2
+        and higher.
+        * passes.c (init_optimization_passes): Use new pass.
+        * params.def (PARAM_IF_TO_SWITCH_THRESHOLD): New param.
+        * doc/invoke.texi (-ftree-if-to-switch-conversion)
+        (if-to-switch-threshold): New item.
+        * doc/invoke.texi (Optimization Options, option -O2): Add
+        -ftree-if-to-switch-conversion.
+        * Makefile.in (OBJS-common): Add tree-if-switch-conversion.o.
+        * Makefile.in (tree-if-switch-conversion.o): New rule.
+
+=== modified file 'gcc/Makefile.in'
+Index: gcc-4_5-branch/gcc/Makefile.in
+===================================================================
+--- gcc-4_5-branch.orig/gcc/Makefile.in
++++ gcc-4_5-branch/gcc/Makefile.in
+@@ -1354,6 +1354,7 @@ OBJS-common = \
+        tree-profile.o \
+        tree-scalar-evolution.o \
+        tree-sra.o \
++       tree-if-switch-conversion.o \
+        tree-switch-conversion.o \
+        tree-ssa-address.o \
+        tree-ssa-alias.o \
+@@ -3013,6 +3014,11 @@ tree-sra.o : tree-sra.c $(CONFIG_H) $(SY
+    $(TM_H) $(TREE_H) $(GIMPLE_H) $(CGRAPH_H) $(TREE_FLOW_H) $(IPA_PROP_H) \
+    $(DIAGNOSTIC_H) statistics.h $(TREE_DUMP_H) $(TIMEVAR_H) $(PARAMS_H) \
+    $(TARGET_H) $(FLAGS_H) $(EXPR_H) $(TREE_INLINE_H)
++tree-if-switch-conversion.o : tree-if-switch-conversion.c $(CONFIG_H) \
++    $(SYSTEM_H) $(TREE_H) $(TM_P_H) $(TREE_FLOW_H) $(DIAGNOSTIC_H) \
++    $(TREE_INLINE_H) $(TIMEVAR_H) $(TM_H) coretypes.h $(TREE_DUMP_H) \
++    $(GIMPLE_H) $(TREE_PASS_H) $(FLAGS_H) $(EXPR_H) $(BASIC_BLOCK_H) output.h \
++    $(GGC_H) $(OBSTACK_H) $(PARAMS_H) $(CPPLIB_H) $(PARAMS_H)
+ tree-switch-conversion.o : tree-switch-conversion.c $(CONFIG_H) $(SYSTEM_H) \
+     $(TREE_H) $(TM_P_H) $(TREE_FLOW_H) $(DIAGNOSTIC_H) $(TREE_INLINE_H) \
+     $(TIMEVAR_H) $(TM_H) coretypes.h $(TREE_DUMP_H) $(GIMPLE_H) \
+Index: gcc-4_5-branch/gcc/common.opt
+===================================================================
+--- gcc-4_5-branch.orig/gcc/common.opt
++++ gcc-4_5-branch/gcc/common.opt
+@@ -1285,6 +1285,10 @@ ftree-switch-conversion
+ Common Report Var(flag_tree_switch_conversion) Optimization
+ Perform conversions of switch initializations.
+ 
++ftree-if-to-switch-conversion
++Common Report Var(flag_tree_if_to_switch_conversion) Optimization
++Perform conversions of chains of ifs into switches.
++
+ ftree-dce
+ Common Report Var(flag_tree_dce) Optimization
+ Enable SSA dead code elimination optimization on trees
+Index: gcc-4_5-branch/gcc/doc/invoke.texi
+===================================================================
+--- gcc-4_5-branch.orig/gcc/doc/invoke.texi
++++ gcc-4_5-branch/gcc/doc/invoke.texi
+@@ -382,7 +382,8 @@ Objective-C and Objective-C++ Dialects}.
+ -fstrict-aliasing -fstrict-overflow -fthread-jumps -ftracer @gol
+ -ftree-builtin-call-dce -ftree-ccp -ftree-ch -ftree-copy-prop @gol
+ -ftree-copyrename -ftree-dce @gol
+--ftree-dominator-opts -ftree-dse -ftree-forwprop -ftree-fre -ftree-loop-im @gol
++-ftree-dominator-opts -ftree-dse -ftree-forwprop -ftree-fre @gol
++-ftree-if-to-switch-conversion -ftree-loop-im @gol
+ -ftree-phiprop -ftree-loop-distribution @gol
+ -ftree-loop-ivcanon -ftree-loop-linear -ftree-loop-optimize @gol
+ -ftree-parallelize-loops=@var{n} -ftree-pre -ftree-pta -ftree-reassoc @gol
+@@ -5798,6 +5799,7 @@ also turns on the following optimization
+ -fsched-interblock  -fsched-spec @gol
+ -fschedule-insns  -fschedule-insns2 @gol
+ -fstrict-aliasing -fstrict-overflow @gol
++-ftree-if-to-switch-conversion @gol
+ -ftree-switch-conversion @gol
+ -ftree-pre @gol
+ -ftree-vrp}
+@@ -6634,6 +6636,10 @@ Perform conversion of simple initializat
+ initializations from a scalar array.  This flag is enabled by default
+ at @option{-O2} and higher.
+ 
++@item -ftree-if-to-switch-conversion
++Perform conversion of chains of ifs into switches.  This flag is enabled by
++default at @option{-O2} and higher.
++
+ @item -ftree-dce
+ @opindex ftree-dce
+ Perform dead code elimination (DCE) on trees.  This flag is enabled by
+@@ -8577,6 +8583,12 @@ loop in the loop nest by a given number 
+ length can be changed using the @option{loop-block-tile-size}
+ parameter.  The default value is 51 iterations.
+ 
++@item if-to-switch-threshold
++If-chain to switch conversion, enabled by
++@option{-ftree-if-to-switch-conversion} convert chains of ifs of sufficient
++length into switches.  The parameter @option{if-to-switch-threshold} can be
++used to set the minimal required length.  The default value is 3.
++
+ @end table
+ @end table
+ 
+Index: gcc-4_5-branch/gcc/opts.c
+===================================================================
+--- gcc-4_5-branch.orig/gcc/opts.c
++++ gcc-4_5-branch/gcc/opts.c
+@@ -905,6 +905,7 @@ decode_options (unsigned int argc, const
+   flag_tree_builtin_call_dce = opt2;
+   flag_tree_pre = opt2;
+   flag_tree_switch_conversion = opt2;
++  flag_tree_if_to_switch_conversion = opt2;
+   flag_ipa_cp = opt2;
+   flag_ipa_sra = opt2;
+   flag_ee = opt2;
+Index: gcc-4_5-branch/gcc/params.def
+===================================================================
+--- gcc-4_5-branch.orig/gcc/params.def
++++ gcc-4_5-branch/gcc/params.def
+@@ -826,6 +826,11 @@ DEFPARAM (PARAM_IPA_SRA_PTR_GROWTH_FACTO
+          "a pointer to an aggregate with",
+          2, 0, 0)
+ 
++DEFPARAM (PARAM_IF_TO_SWITCH_THRESHOLD,
++         "if-to-switch-threshold",
++         "Threshold for converting an if-chain into a switch",
++         3, 0, 0)
++
+ /*
+ Local variables:
+ mode:c
+Index: gcc-4_5-branch/gcc/passes.c
+===================================================================
+--- gcc-4_5-branch.orig/gcc/passes.c
++++ gcc-4_5-branch/gcc/passes.c
+@@ -788,6 +788,7 @@ init_optimization_passes (void)
+          NEXT_PASS (pass_cd_dce);
+          NEXT_PASS (pass_early_ipa_sra);
+          NEXT_PASS (pass_tail_recursion);
++         NEXT_PASS (pass_if_to_switch);
+          NEXT_PASS (pass_convert_switch);
+           NEXT_PASS (pass_cleanup_eh);
+           NEXT_PASS (pass_profile);
+@@ -844,6 +845,7 @@ init_optimization_passes (void)
+       NEXT_PASS (pass_phiprop);
+       NEXT_PASS (pass_fre);
+       NEXT_PASS (pass_copy_prop);
++      NEXT_PASS (pass_if_to_switch);
+       NEXT_PASS (pass_merge_phi);
+       NEXT_PASS (pass_vrp);
+       NEXT_PASS (pass_dce);
+Index: gcc-4_5-branch/gcc/tree-if-switch-conversion.c
+===================================================================
+--- /dev/null
++++ gcc-4_5-branch/gcc/tree-if-switch-conversion.c
+@@ -0,0 +1,643 @@
++/* Convert a chain of ifs into a switch.
++   Copyright (C) 2010 Free Software Foundation, Inc.
++   Contributed by Tom de Vries <tom@codesourcery.com>
++
++This file is part of GCC.
++
++GCC is free software; you can redistribute it and/or modify it
++under the terms of the GNU General Public License as published by the
++Free Software Foundation; either version 3, or (at your option) any
++later version.
++
++GCC is distributed in the hope that it will be useful, but WITHOUT
++ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
++for more details.
++
++You should have received a copy of the GNU General Public License
++along with GCC; see the file COPYING3.  If not, write to the Free
++Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
++02110-1301, USA.  */
++
++
++/* The following pass converts a chain of ifs into a switch.
++
++   The if-chain has the following properties:
++   - all bbs end in a GIMPLE_COND.
++   - all but the first bb are empty, apart from the GIMPLE_COND.
++   - the GIMPLE_CONDs compare the same variable against integer constants.
++   - the true gotos all target the same bb.
++   - the false gotos target the next in the if-chain.
++
++   F.i., consider the following if-chain:
++   ...
++   <bb 4>:
++   ...
++   if (D.1993_3 == 32)
++     goto <bb 3>;
++   else
++     goto <bb 5>;
++
++   <bb 5>:
++   if (D.1993_3 == 13)
++     goto <bb 3>;
++   else
++     goto <bb 6>;
++
++   <bb 6>:
++   if (D.1993_3 == 10)
++     goto <bb 3>;
++   else
++     goto <bb 7>;
++
++   <bb 7>:
++   if (D.1993_3 == 9)
++     goto <bb 3>;
++   else
++     goto <bb 8>;
++   ...
++
++   The pass will report this if-chain like this:
++   ...
++   var: D.1993_3
++   first: <bb 4>
++   true: <bb 3>
++   last: <bb 7>
++   constants: 9 10 13 32
++   ...
++
++   and then convert the if-chain into a switch:
++   ...
++   <bb 4>:
++   ...
++   switch (D.1993_3) <default: <L8>,
++                      case 9: <L7>,
++                      case 10: <L7>,
++                      case 13: <L7>,
++                      case 32: <L7>>
++   ...
++
++   The conversion does not happen if the chain is too short.  The threshold is
++   determined by the parameter PARAM_IF_TO_SWITCH_THRESHOLD.
++
++   The pass will try to construct a chain for each bb, unless the bb it is
++   already contained in a chain.  This ensures that all chains will be found,
++   and that no chain will be constructed twice.  The pass constructs and
++   converts the chains one-by-one, rather than first calculating all the chains
++   and then doing the conversions.
++
++   The pass could detect range-checks in analyze_bb as well, and handle them.
++   Simple ones, like 'c <= 5', and more complex ones, like
++   '(unsigned char) c + 247 <= 1', which is generated by the C front-end from
++   code like '(c == 9 || c == 10)' or '(9 <= c && c <= 10)'.  */
++
++#include "config.h"
++#include "system.h"
++#include "coretypes.h"
++#include "tm.h"
++
++#include "params.h"
++#include "flags.h"
++#include "tree.h"
++#include "basic-block.h"
++#include "tree-flow.h"
++#include "tree-flow-inline.h"
++#include "tree-ssa-operands.h"
++#include "diagnostic.h"
++#include "tree-pass.h"
++#include "tree-dump.h"
++#include "timevar.h"
++
++/* Information we've collected about a single bb.  */
++
++struct ifsc_info
++{
++  /* The variable of the bb's ending GIMPLE_COND, NULL_TREE if not present.  */
++  tree var;
++  /* The cond_code of the bb's ending GIMPLE_COND.  */
++  enum tree_code cond_code;
++  /* The constant of the bb's ending GIMPLE_COND.  */
++  tree constant;
++  /* Successor edge of the bb if its GIMPLE_COND is true.  */
++  edge true_edge;
++  /* Successor edge of the bb if its GIMPLE_COND is false.  */
++  edge false_edge;
++  /* Set if the bb has valid ifsc_info.  */
++   bool valid;
++  /* Set if the bb is part of a chain.  */
++  bool chained;
++};
++
++/* Macros to access the fields of struct ifsc_info.  */
++
++#define BB_IFSC_VAR(bb) (((struct ifsc_info *)bb->aux)->var)
++#define BB_IFSC_COND_CODE(bb) (((struct ifsc_info *)bb->aux)->cond_code)
++#define BB_IFSC_CONSTANT(bb) (((struct ifsc_info *)bb->aux)->constant)
++#define BB_IFSC_TRUE_EDGE(bb) (((struct ifsc_info *)bb->aux)->true_edge)
++#define BB_IFSC_FALSE_EDGE(bb) (((struct ifsc_info *)bb->aux)->false_edge)
++#define BB_IFSC_VALID(bb) (((struct ifsc_info *)bb->aux)->valid)
++#define BB_IFSC_CHAINED(bb) (((struct ifsc_info *)bb->aux)->chained)
++
++/* Data-type describing an if-chain.  */
++
++struct if_chain
++{
++  /* First bb in the chain.  */
++  basic_block first;
++  /* Last bb in the chain.  */
++  basic_block last;
++  /* Variable that GIMPLE_CONDs of all bbs in chain compare against.  */
++  tree var;
++  /* bb that all GIMPLE_CONDs jump to if comparison succeeds.  */
++  basic_block true_dest;
++  /* Constants that GIMPLE_CONDs of all bbs in chain compare var against.  */
++  VEC (tree, heap) *constants;
++  /* Same as previous, but sorted and with duplicates removed.  */
++  VEC (tree, heap) *unique_constants;
++};
++
++/* Utility macro.  */
++
++#define SWAP(T, X, Y) do { T tmp = (X); (X) = (Y); (Y) = tmp; } while (0)
++
++/* Helper function for sort_constants.  */
++
++static int
++compare_constants (const void *p1, const void *p2)
++{
++  const_tree const c1 = *(const_tree const*)p1;
++  const_tree const c2 = *(const_tree const*)p2;
++
++  return tree_int_cst_compare (c1, c2);
++}
++
++/* Sort constants in constants and copy to unique_constants, while skipping
++   duplicates.  */
++
++static void
++sort_constants (VEC (tree,heap) *constants, VEC (tree,heap) **unique_constants)
++{
++  size_t len = VEC_length (tree, constants);
++  unsigned int ix;
++  tree prev = NULL_TREE, constant;
++
++  /* Sort constants.  */
++  qsort (VEC_address (tree, constants), len, sizeof (tree),
++         compare_constants);
++
++  /* Copy to unique_constants, while skipping duplicates.  */
++  for (ix = 0; VEC_iterate (tree, constants, ix, constant); ix++)
++    {
++      if (prev != NULL_TREE && tree_int_cst_compare (prev, constant) == 0)
++        continue;
++      prev = constant;
++
++      VEC_safe_push (tree, heap, *unique_constants, constant);
++    }
++}
++
++/* Get true_edge and false_edge of a bb ending in a conditional jump.  */
++
++static void
++get_edges (basic_block bb, edge *true_edge, edge *false_edge)
++{
++  edge e0, e1;
++  int e0_true;
++  int n = EDGE_COUNT (bb->succs);
++  gcc_assert (n == 2);
++
++  e0 = EDGE_SUCC (bb, 0);
++  e1 = EDGE_SUCC (bb, 1);
++
++  e0_true = e0->flags & EDGE_TRUE_VALUE;
++
++  *true_edge = e0_true ? e0 : e1;
++  *false_edge = e0_true ? e1 : e0;
++
++  gcc_assert ((*true_edge)->flags & EDGE_TRUE_VALUE);
++  gcc_assert ((*false_edge)->flags & EDGE_FALSE_VALUE);
++
++  gcc_assert (((*true_edge)->flags & EDGE_FALLTHRU) == 0);
++  gcc_assert (((*false_edge)->flags & EDGE_FALLTHRU) == 0);
++}
++
++/* Analyze bb and store results in ifsc_info struct.  */
++
++static void
++analyze_bb (basic_block bb)
++{
++  gimple stmt = last_stmt (bb);
++  tree lhs, rhs, var, constant;
++  edge true_edge, false_edge;
++  enum tree_code cond_code;
++
++  /* Don't redo analysis.  */
++  if (BB_IFSC_VALID (bb))
++    return;
++  BB_IFSC_VALID (bb) = true;
++
++
++  /* bb needs to end in GIMPLE_COND.  */
++  if (!stmt || gimple_code (stmt) != GIMPLE_COND)
++    return;
++
++  /* bb needs to end in EQ_EXPR or NE_EXPR.  */
++  cond_code = gimple_cond_code (stmt);
++  if (cond_code != EQ_EXPR && cond_code != NE_EXPR)
++    return;
++
++  lhs = gimple_cond_lhs (stmt);
++  rhs = gimple_cond_rhs (stmt);
++
++  /* GIMPLE_COND needs to compare variable to constant.  */
++  if ((TREE_CONSTANT (lhs) == 0)
++      == (TREE_CONSTANT (rhs) == 0))
++    return;
++
++  var = TREE_CONSTANT (lhs) ? rhs : lhs;
++  constant = TREE_CONSTANT (lhs)? lhs : rhs;
++
++  /* Switches cannot handle non-integral types.  */
++  if (!INTEGRAL_TYPE_P(TREE_TYPE (var)))
++    return;
++
++  get_edges (bb, &true_edge, &false_edge);
++
++  if (cond_code == NE_EXPR)
++    SWAP (edge, true_edge, false_edge);
++
++  /* TODO: loosen this constraint.  In principle it's ok if true_edge->dest has
++     phis, as long as for each phi all the edges coming from the chain have the
++     same value.  */
++  if (!gimple_seq_empty_p (phi_nodes (true_edge->dest)))
++    return;
++
++  /* Store analysis in ifsc_info struct.  */
++  BB_IFSC_VAR (bb) = var;
++  BB_IFSC_COND_CODE (bb) = cond_code;
++  BB_IFSC_CONSTANT (bb) = constant;
++  BB_IFSC_TRUE_EDGE (bb) = true_edge;
++  BB_IFSC_FALSE_EDGE (bb) = false_edge;
++}
++
++/* Grow if-chain forward.  */
++
++static void
++grow_if_chain_forward (struct if_chain *chain)
++{
++  basic_block next_bb;
++
++  while (1)
++    {
++      next_bb = BB_IFSC_FALSE_EDGE (chain->last)->dest;
++
++      /* next_bb is already part of another chain.  */
++      if (BB_IFSC_CHAINED (next_bb))
++        break;
++
++      /* next_bb needs to be dominated by the last bb.  */
++      if (!single_pred_p (next_bb))
++        break;
++
++      analyze_bb (next_bb);
++
++      /* Does next_bb fit in chain?  */
++      if (BB_IFSC_VAR (next_bb) != chain->var
++          || BB_IFSC_TRUE_EDGE (next_bb)->dest != chain->true_dest)
++        break;
++
++      /* We can only add empty bbs at the end of the chain.  */
++      if (first_stmt (next_bb) != last_stmt (next_bb))
++        break;
++
++      /* Add next_bb at end of chain.  */
++      VEC_safe_push (tree, heap, chain->constants, BB_IFSC_CONSTANT (next_bb));
++      BB_IFSC_CHAINED (next_bb) = true;
++      chain->last = next_bb;
++    }
++}
++
++/* Grow if-chain backward.  */
++
++static void
++grow_if_chain_backward (struct if_chain *chain)
++{
++  basic_block prev_bb;
++
++  while (1)
++    {
++      /* First bb is not empty, cannot grow backwards.  */
++      if (first_stmt (chain->first) != last_stmt (chain->first))
++        break;
++
++      /* First bb has no single predecessor, cannot grow backwards.  */
++      if (!single_pred_p (chain->first))
++        break;
++
++      prev_bb = single_pred (chain->first);
++
++      /* prev_bb is already part of another chain.  */
++      if (BB_IFSC_CHAINED (prev_bb))
++        break;
++
++      analyze_bb (prev_bb);
++
++      /* Does prev_bb fit in chain?  */
++      if (BB_IFSC_VAR (prev_bb) != chain->var
++          || BB_IFSC_TRUE_EDGE (prev_bb)->dest != chain->true_dest)
++        break;
++
++      /* Add prev_bb at beginning of chain.  */
++      VEC_safe_push (tree, heap, chain->constants, BB_IFSC_CONSTANT (prev_bb));
++      BB_IFSC_CHAINED (prev_bb) = true;
++      chain->first = prev_bb;
++    }
++}
++
++/* Grow if-chain containing bb.  */
++
++static void
++grow_if_chain (basic_block bb, struct if_chain *chain)
++{
++  /* Initialize chain to empty.  */
++  VEC_truncate (tree, chain->constants, 0);
++  VEC_truncate (tree, chain->unique_constants, 0);
++
++  /* bb is already part of another chain.  */
++  if (BB_IFSC_CHAINED (bb))
++    return;
++
++  analyze_bb (bb);
++
++  /* bb is not fit to be part of a chain.  */
++  if (BB_IFSC_VAR (bb) == NULL_TREE)
++    return;
++
++  /* Set bb as initial part of the chain.  */
++  VEC_safe_push (tree, heap, chain->constants, BB_IFSC_CONSTANT (bb));
++  chain->first = chain->last = bb;
++  chain->var = BB_IFSC_VAR (bb);
++  chain->true_dest = BB_IFSC_TRUE_EDGE (bb)->dest;
++
++  /* bb is part of a chain now.  */
++  BB_IFSC_CHAINED (bb) = true;
++
++  /* Grow chain to its maximum size.  */
++  grow_if_chain_forward (chain);
++  grow_if_chain_backward (chain);
++
++  /* Sort constants and skip duplicates.  */
++  sort_constants (chain->constants, &chain->unique_constants);
++}
++
++static void
++dump_tree_vector (VEC (tree, heap) *vec)
++{
++  unsigned int ix;
++  tree constant;
++
++  for (ix = 0; VEC_iterate (tree, vec, ix, constant); ix++)
++    {
++      if (ix != 0)
++        fprintf (dump_file, " ");
++      print_generic_expr (dump_file, constant, 0);
++    }
++  fprintf (dump_file, "\n");
++}
++
++/* Dump if-chain to dump_file.  */
++
++static void
++dump_if_chain (struct if_chain *chain)
++{
++  if (!dump_file)
++    return;
++
++  fprintf (dump_file, "var: ");
++  print_generic_expr (dump_file, chain->var, 0);
++  fprintf (dump_file, "\n");
++  fprintf (dump_file, "first: <bb %d>\n", chain->first->index);
++  fprintf (dump_file, "true: <bb %d>\n", chain->true_dest->index);
++  fprintf (dump_file, "last: <bb %d>\n",chain->last->index);
++
++  fprintf (dump_file, "constants: ");
++  dump_tree_vector (chain->constants);
++
++  if (VEC_length (tree, chain->unique_constants)
++      != VEC_length (tree, chain->constants))
++    {
++      fprintf (dump_file, "unique_constants: ");
++      dump_tree_vector (chain->unique_constants);
++    }
++}
++
++/* Remove redundant bbs and edges.  */
++
++static void
++remove_redundant_bbs_and_edges (struct if_chain *chain, int *false_prob)
++{
++  basic_block bb, next;
++  edge true_edge, false_edge;
++
++  for (bb = chain->first;; bb = next)
++    {
++      true_edge = BB_IFSC_TRUE_EDGE (bb);
++      false_edge = BB_IFSC_FALSE_EDGE (bb);
++
++      /* Determine next, before we delete false_edge.  */
++      next = false_edge->dest;
++
++      /* Accumulate probability.  */
++      *false_prob = (*false_prob * false_edge->probability) / REG_BR_PROB_BASE;
++
++      /* Don't remove the new true_edge.  */
++      if (bb != chain->first)
++        remove_edge (true_edge);
++
++      /* Don't remove the new false_edge.  */
++      if (bb != chain->last)
++        remove_edge (false_edge);
++
++      /* Don't remove the first bb.  */
++      if (bb != chain->first)
++        delete_basic_block (bb);
++
++      /* Stop after last.  */
++      if (bb == chain->last)
++        break;
++    }
++}
++
++/* Update control flow graph.  */
++
++static void
++update_cfg (struct if_chain *chain)
++{
++  edge true_edge, false_edge;
++  int false_prob;
++  int flags_mask = ~(EDGE_FALLTHRU|EDGE_TRUE_VALUE|EDGE_FALSE_VALUE);
++
++  /* We keep these 2 edges, and remove the rest.  We need this specific
++     false_edge, because a phi in chain->last->dest might reference (the index
++     of) this edge.  For true_edge, we could pick any of them.  */
++  true_edge = BB_IFSC_TRUE_EDGE (chain->first);
++  false_edge = BB_IFSC_FALSE_EDGE (chain->last);
++
++  /* Update true edge.  */
++  true_edge->flags &= flags_mask;
++
++  /* Update false edge.  */
++  redirect_edge_pred (false_edge, chain->first);
++  false_edge->flags &= flags_mask;
++
++  false_prob = REG_BR_PROB_BASE;
++  remove_redundant_bbs_and_edges (chain, &false_prob);
++
++  /* Repair probabilities.  */
++  true_edge->probability = REG_BR_PROB_BASE - false_prob;
++  false_edge->probability = false_prob;
++
++  /* Force recalculation of dominance info.  */
++  free_dominance_info (CDI_DOMINATORS);
++  free_dominance_info (CDI_POST_DOMINATORS);
++}
++
++/* Create switch statement.  Borrows from gimplify_switch_expr.  */
++
++static void
++convert_if_chain_to_switch (struct if_chain *chain)
++{
++  tree label_decl_true, label_decl_false;
++  gimple label_true, label_false, gimple_switch;
++  gimple_stmt_iterator gsi;
++  tree default_case, other_case, constant;
++  unsigned int ix;
++  VEC (tree, heap) *labels;
++
++  labels = VEC_alloc (tree, heap, 8);
++
++  /* Create and insert true jump label.  */
++  label_decl_true = create_artificial_label (UNKNOWN_LOCATION);
++  label_true = gimple_build_label (label_decl_true);
++  gsi = gsi_start_bb (chain->true_dest);
++  gsi_insert_before (&gsi, label_true, GSI_SAME_STMT);
++
++  /* Create and insert false jump label.  */
++  label_decl_false = create_artificial_label (UNKNOWN_LOCATION);
++  label_false = gimple_build_label (label_decl_false);
++  gsi = gsi_start_bb (BB_IFSC_FALSE_EDGE (chain->last)->dest);
++  gsi_insert_before (&gsi, label_false, GSI_SAME_STMT);
++
++  /* Create default case label.  */
++  default_case = build3 (CASE_LABEL_EXPR, void_type_node,
++                         NULL_TREE, NULL_TREE,
++                         label_decl_false);
++
++  /* Create case labels.  */
++  for (ix = 0; VEC_iterate (tree, chain->unique_constants, ix, constant); ix++)
++    {
++      /* TODO: use ranges, as in gimplify_switch_expr.  */
++      other_case = build3 (CASE_LABEL_EXPR, void_type_node,
++                           constant, NULL_TREE,
++                           label_decl_true);
++      VEC_safe_push (tree, heap, labels, other_case);
++    }
++
++  /* Create and insert switch.  */
++  gimple_switch = gimple_build_switch_vec (chain->var, default_case, labels);
++  gsi = gsi_for_stmt (last_stmt (chain->first));
++  gsi_insert_before (&gsi, gimple_switch, GSI_SAME_STMT);
++
++  /* Remove now obsolete if.  */
++  gsi_remove (&gsi, true);
++
++  VEC_free (tree, heap, labels);
++}
++
++/* Allocation and initialization.  */
++
++static void
++init_pass (struct if_chain *chain)
++{
++  alloc_aux_for_blocks (sizeof (struct ifsc_info));
++
++  chain->constants = VEC_alloc (tree, heap, 8);
++  chain->unique_constants = VEC_alloc (tree, heap, 8);
++}
++
++/* Deallocation.  */
++
++static void
++finish_pass (struct if_chain *chain)
++{
++  free_aux_for_blocks ();
++
++  VEC_free (tree, heap, chain->constants);
++  VEC_free (tree, heap, chain->unique_constants);
++}
++
++/* Find if-chains and convert them to switches.  */
++
++static unsigned int
++do_if_to_switch (void)
++{
++  basic_block bb;
++  struct if_chain chain;
++  unsigned int convert_threshold = PARAM_VALUE (PARAM_IF_TO_SWITCH_THRESHOLD);
++
++  init_pass (&chain);
++
++  for (bb = cfun->cfg->x_entry_block_ptr->next_bb;
++       bb != cfun->cfg->x_exit_block_ptr;)
++    {
++      grow_if_chain (bb, &chain);
++
++      do
++        bb = bb->next_bb;
++      while (BB_IFSC_CHAINED (bb));
++
++      /* Determine if the chain is long enough.  */
++      if (VEC_length (tree, chain.unique_constants) < convert_threshold)
++        continue;
++
++      dump_if_chain (&chain);
++
++      convert_if_chain_to_switch (&chain);
++
++      update_cfg (&chain);
++    }
++
++  finish_pass (&chain);
++
++  return 0;
++}
++
++/* The pass gate.  */
++
++static bool
++if_to_switch_gate (void)
++{
++  return flag_tree_if_to_switch_conversion;
++}
++
++/* The pass definition.  */
++
++struct gimple_opt_pass pass_if_to_switch =
++{
++ {
++  GIMPLE_PASS,
++  "iftoswitch",                         /* name */
++  if_to_switch_gate,                    /* gate */
++  do_if_to_switch,                      /* execute */
++  NULL,                                 /* sub */
++  NULL,                                 /* next */
++  0,                                    /* static_pass_number */
++  TV_TREE_SWITCH_CONVERSION,            /* tv_id */
++  PROP_cfg | PROP_ssa,                  /* properties_required */
++  0,                                    /* properties_provided */
++  0,                                    /* properties_destroyed */
++  0,                                    /* todo_flags_start */
++  TODO_update_ssa | TODO_dump_func
++  | TODO_ggc_collect | TODO_verify_ssa  /* todo_flags_finish */
++ }
++};
+Index: gcc-4_5-branch/gcc/tree-pass.h
+===================================================================
+--- gcc-4_5-branch.orig/gcc/tree-pass.h
++++ gcc-4_5-branch/gcc/tree-pass.h
+@@ -560,6 +560,7 @@ extern struct gimple_opt_pass pass_inlin
+ extern struct gimple_opt_pass pass_all_early_optimizations;
+ extern struct gimple_opt_pass pass_update_address_taken;
+ extern struct gimple_opt_pass pass_convert_switch;
++extern struct gimple_opt_pass pass_if_to_switch;
+ 
+ /* The root of the compilation pass tree, once constructed.  */
+ extern struct opt_pass *all_passes, *all_small_ipa_passes, *all_lowering_passes,