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-rw-r--r--meta-oe/recipes-devtools/gcc/gcc-4.5/linaro/gcc-4.5-linaro-r99468.patch811
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 0000000000..cf22aaf16f
--- /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,