diff options
Diffstat (limited to 'gcc/tree-into-ssa.c')
| -rw-r--r-- | gcc/tree-into-ssa.c | 49 |
1 files changed, 24 insertions, 25 deletions
diff --git a/gcc/tree-into-ssa.c b/gcc/tree-into-ssa.c index 18b00a888ea..c1da5e4fcbb 100644 --- a/gcc/tree-into-ssa.c +++ b/gcc/tree-into-ssa.c @@ -128,6 +128,30 @@ struct mark_def_sites_global_data bitmap kills; }; +/* It is advantageous to avoid things like life analysis for variables which + do not need PHI nodes. This enum describes whether or not a particular + variable may need a PHI node. */ + +enum need_phi_state { + /* This is the default. If we are still in this state after finding + all the definition and use sites, then we will assume the variable + needs PHI nodes. This is probably an overly conservative assumption. */ + NEED_PHI_STATE_UNKNOWN, + + /* This state indicates that we have seen one or more sets of the + variable in a single basic block and that the sets dominate all + uses seen so far. If after finding all definition and use sites + we are still in this state, then the variable does not need any + PHI nodes. */ + NEED_PHI_STATE_NO, + + /* This state indicates that we have either seen multiple definitions of + the variable in multiple blocks, or that we encountered a use in a + block that was not dominated by the block containing the set(s) of + this variable. This variable is assumed to need PHI nodes. */ + NEED_PHI_STATE_MAYBE +}; + /* Information stored for both SSA names and decls. */ struct common_info_d { @@ -1494,31 +1518,6 @@ rewrite_dom_walker::after_dom_children (basic_block bb ATTRIBUTE_UNUSED) /* Dump bitmap SET (assumed to contain VAR_DECLs) to FILE. */ -void -dump_decl_set (FILE *file, bitmap set) -{ - if (set) - { - bitmap_iterator bi; - unsigned i; - - fprintf (file, "{ "); - - EXECUTE_IF_SET_IN_BITMAP (set, 0, i, bi) - { - fprintf (file, "D.%u", i); - fprintf (file, " "); - } - - fprintf (file, "}"); - } - else - fprintf (file, "NIL"); -} - - -/* Dump bitmap SET (assumed to contain VAR_DECLs) to FILE. */ - DEBUG_FUNCTION void debug_decl_set (bitmap set) { |