X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;ds=sidebyside;f=gcc%2Ftree-ssa-copyrename.c;h=c236de34d962db731a2e3db16e55a102b7fd088d;hb=eca87a93f3e4482e01ffcbce86525bbd87dc7993;hp=ed221c2f3e08565a0291cc3831ec8a6c05023dba;hpb=2a3ebafa45c591f2c37dcc249816c71c7930245b;p=pf3gnuchains%2Fgcc-fork.git diff --git a/gcc/tree-ssa-copyrename.c b/gcc/tree-ssa-copyrename.c index ed221c2f3e0..c236de34d96 100644 --- a/gcc/tree-ssa-copyrename.c +++ b/gcc/tree-ssa-copyrename.c @@ -1,5 +1,6 @@ /* Rename SSA copies. - Copyright (C) 2004, 2006, 2007, 2008 Free Software Foundation, Inc. + Copyright (C) 2004, 2006, 2007, 2008, 2009, 2010 + Free Software Foundation, Inc. Contributed by Andrew MacLeod This file is part of GCC. @@ -28,6 +29,7 @@ along with GCC; see the file COPYING3. If not see #include "basic-block.h" #include "function.h" #include "diagnostic.h" +#include "tree-pretty-print.h" #include "bitmap.h" #include "tree-flow.h" #include "gimple.h" @@ -50,22 +52,22 @@ along with GCC; see the file COPYING3. If not see T.3_5 = a_1 = T.3_5 - If this copy couldn't be copy propagated, it could possibly remain in the - program throughout the optimization phases. After SSA->normal, it would + If this copy couldn't be copy propagated, it could possibly remain in the + program throughout the optimization phases. After SSA->normal, it would become: T.3 = a = T.3 - - Since T.3_5 is distinct from all other SSA versions of T.3, there is no - fundamental reason why the base variable needs to be T.3, subject to - certain restrictions. This optimization attempts to determine if we can + + Since T.3_5 is distinct from all other SSA versions of T.3, there is no + fundamental reason why the base variable needs to be T.3, subject to + certain restrictions. This optimization attempts to determine if we can change the base variable on copies like this, and result in code such as: a_5 = a_1 = a_5 - This gives the SSA->normal pass a shot at coalescing a_1 and a_5. If it is + This gives the SSA->normal pass a shot at coalescing a_1 and a_5. If it is possible, the copy goes away completely. If it isn't possible, a new temp will be created for a_5, and you will end up with the exact same code: @@ -79,8 +81,8 @@ along with GCC; see the file COPYING3. If not see a_1 = = a_1 - get turned into - + get turned into + T.3_5 = a_1 = T.3_5 = a_1 @@ -99,7 +101,7 @@ along with GCC; see the file COPYING3. If not see = a_1 which copy propagation would then turn into: - + a_5 = = a_5 @@ -187,7 +189,7 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug) ign1 = TREE_CODE (root1) == VAR_DECL && DECL_IGNORED_P (root1); ign2 = TREE_CODE (root2) == VAR_DECL && DECL_IGNORED_P (root2); - /* Never attempt to coalesce 2 user variables unless one is an inline + /* Never attempt to coalesce 2 user variables unless one is an inline variable. */ if (!ign1 && !ign2) { @@ -195,7 +197,7 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug) ign2 = true; else if (DECL_FROM_INLINE (root1)) ign1 = true; - else + else { if (debug) fprintf (debug, " : 2 different USER vars. No coalesce.\n"); @@ -203,7 +205,7 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug) } } - /* If both values have default defs, we can't coalesce. If only one has a + /* If both values have default defs, we can't coalesce. If only one has a tag, make sure that variable is the new root partition. */ if (gimple_default_def (cfun, root1)) { @@ -236,7 +238,7 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug) /* Merge the two partitions. */ p3 = partition_union (map->var_partition, p1, p2); - /* Set the root variable of the partition to the better choice, if there is + /* Set the root variable of the partition to the better choice, if there is one. */ if (!ign2) replace_ssa_name_symbol (partition_to_var (map, p3), root2); @@ -246,7 +248,7 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug) if (debug) { fprintf (debug, " --> P%d ", p3); - print_generic_expr (debug, SSA_NAME_VAR (partition_to_var (map, p3)), + print_generic_expr (debug, SSA_NAME_VAR (partition_to_var (map, p3)), TDF_SLIM); fprintf (debug, "\n"); } @@ -256,8 +258,8 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug) /* This function will make a pass through the IL, and attempt to coalesce any SSA versions which occur in PHI's or copies. Coalescing is accomplished by - changing the underlying root variable of all coalesced version. This will - then cause the SSA->normal pass to attempt to coalesce them all to the same + changing the underlying root variable of all coalesced version. This will + then cause the SSA->normal pass to attempt to coalesce them all to the same variable. */ static unsigned int @@ -324,7 +326,7 @@ rename_ssa_copies (void) /* Now one more pass to make all elements of a partition share the same root variable. */ - + for (x = 1; x < num_ssa_names; x++) { part_var = partition_to_var (map, x); @@ -357,7 +359,7 @@ gate_copyrename (void) return flag_tree_copyrename != 0; } -struct gimple_opt_pass pass_rename_ssa_copies = +struct gimple_opt_pass pass_rename_ssa_copies = { { GIMPLE_PASS, @@ -371,7 +373,7 @@ struct gimple_opt_pass pass_rename_ssa_copies = PROP_cfg | PROP_ssa, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ - 0, /* todo_flags_start */ + 0, /* todo_flags_start */ TODO_dump_func | TODO_verify_ssa /* todo_flags_finish */ } -}; +};