[PATCH] Remove register_new_name_mapping, do less timevar push/pop

[Richard Guenther <rguenther at suse dot de>]

This performs timevar push/pop at the single remaining entry to 
incremental SSA rewrite setup.  The other entry, 
register_new_name_mapping, is removed by making its only other
user use create_new_def_for.  Which needs to handle a NULL DEF
for this case, as we have no access to a DEF op for an SSA name LHS
(but we do for a PHI node).  Something Micha may change soon.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.

Richard.

2012-08-20  Richard Guenther  <rguenther@suse.de>

	* tree-flow.h (register_new_name_mapping): Remove.
	* tree-into-ssa.c (register_new_name_mapping): Likewise.
	(add_new_name_mapping): Do not push/pop timevar here.
	(create_new_def_for): Instead do it here.  Initialize
	update-ssa here, handle a NULL def.
	* tree-vrp.c (build_assert_expr_for): Use create_new_def_for.

Index: gcc/tree-flow.h
===================================================================
*** gcc/tree-flow.h	(revision 190525)
--- gcc/tree-flow.h	(working copy)
*************** void release_defs_bitset (bitmap toremov
*** 516,522 ****
  /* In tree-into-ssa.c  */
  void update_ssa (unsigned);
  void delete_update_ssa (void);
- void register_new_name_mapping (tree, tree);
  tree create_new_def_for (tree, gimple, def_operand_p);
  bool need_ssa_update_p (struct function *);
  bool name_registered_for_update_p (tree);
--- 516,521 ----
Index: gcc/tree-into-ssa.c
===================================================================
*** gcc/tree-into-ssa.c	(revision 190525)
--- gcc/tree-into-ssa.c	(working copy)
*************** static VEC(gimple_vec, heap) *phis_to_re
*** 111,125 ****
  static bitmap blocks_with_phis_to_rewrite;
  
  /* Growth factor for NEW_SSA_NAMES and OLD_SSA_NAMES.  These sets need
!    to grow as the callers to register_new_name_mapping will typically
!    create new names on the fly.  FIXME.  Currently set to 1/3 to avoid
!    frequent reallocations but still need to find a reasonable growth
!    strategy.  */
  #define NAME_SETS_GROWTH_FACTOR	(MAX (3, num_ssa_names / 3))
  
  
  /* The function the SSA updating data structures have been initialized for.
!    NULL if they need to be initialized by register_new_name_mapping.  */
  static struct function *update_ssa_initialized_fn = NULL;
  
  /* Global data to attach to the main dominator walk structure.  */
--- 111,125 ----
  static bitmap blocks_with_phis_to_rewrite;
  
  /* Growth factor for NEW_SSA_NAMES and OLD_SSA_NAMES.  These sets need
!    to grow as the callers to create_new_def_for will create new names on
!    the fly.
!    FIXME.  Currently set to 1/3 to avoid frequent reallocations but still
!    need to find a reasonable growth strategy.  */
  #define NAME_SETS_GROWTH_FACTOR	(MAX (3, num_ssa_names / 3))
  
  
  /* The function the SSA updating data structures have been initialized for.
!    NULL if they need to be initialized by create_new_def_for.  */
  static struct function *update_ssa_initialized_fn = NULL;
  
  /* Global data to attach to the main dominator walk structure.  */
*************** add_to_repl_tbl (tree new_tree, tree old
*** 587,594 ****
  static void
  add_new_name_mapping (tree new_tree, tree old)
  {
-   timevar_push (TV_TREE_SSA_INCREMENTAL);
- 
    /* OLD and NEW_TREE must be different SSA names for the same symbol.  */
    gcc_assert (new_tree != old && SSA_NAME_VAR (new_tree) == SSA_NAME_VAR (old));
  
--- 587,592 ----
*************** add_new_name_mapping (tree new_tree, tre
*** 613,620 ****
       respectively.  */
    SET_BIT (new_ssa_names, SSA_NAME_VERSION (new_tree));
    SET_BIT (old_ssa_names, SSA_NAME_VERSION (old));
- 
-   timevar_pop (TV_TREE_SSA_INCREMENTAL);
  }
  
  
--- 611,616 ----
*************** delete_update_ssa (void)
*** 2842,2857 ****
  
  
  /* Create a new name for OLD_NAME in statement STMT and replace the
!    operand pointed to by DEF_P with the newly created name.  Return
!    the new name and register the replacement mapping <NEW, OLD> in
     update_ssa's tables.  */
  
  tree
  create_new_def_for (tree old_name, gimple stmt, def_operand_p def)
  {
!   tree new_name = duplicate_ssa_name (old_name, stmt);
  
!   SET_DEF (def, new_name);
  
    if (gimple_code (stmt) == GIMPLE_PHI)
      {
--- 2838,2865 ----
  
  
  /* Create a new name for OLD_NAME in statement STMT and replace the
!    operand pointed to by DEF_P with the newly created name.  If DEF_P
!    is NULL then STMT should be a GIMPLE assignment.
!    Return the new name and register the replacement mapping <NEW, OLD> in
     update_ssa's tables.  */
  
  tree
  create_new_def_for (tree old_name, gimple stmt, def_operand_p def)
  {
!   tree new_name;
  
!   timevar_push (TV_TREE_SSA_INCREMENTAL);
! 
!   if (!update_ssa_initialized_fn)
!     init_update_ssa (cfun);
! 
!   gcc_assert (update_ssa_initialized_fn == cfun);
! 
!   new_name = duplicate_ssa_name (old_name, stmt);
!   if (def)
!     SET_DEF (def, new_name);
!   else
!     gimple_assign_set_lhs (stmt, new_name);
  
    if (gimple_code (stmt) == GIMPLE_PHI)
      {
*************** create_new_def_for (tree old_name, gimpl
*** 2861,2890 ****
        SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_name) = bb_has_abnormal_pred (bb);
      }
  
!   register_new_name_mapping (new_name, old_name);
  
    /* For the benefit of passes that will be updating the SSA form on
       their own, set the current reaching definition of OLD_NAME to be
       NEW_NAME.  */
    get_ssa_name_ann (old_name)->info.current_def = new_name;
  
!   return new_name;
! }
! 
! 
! /* Register name NEW to be a replacement for name OLD.  This function
!    must be called for every replacement that should be performed by
!    update_ssa.  */
! 
! void
! register_new_name_mapping (tree new_tree, tree old)
! {
!   if (!update_ssa_initialized_fn)
!     init_update_ssa (cfun);
! 
!   gcc_assert (update_ssa_initialized_fn == cfun);
  
!   add_new_name_mapping (new_tree, old);
  }
  
  
--- 2869,2884 ----
        SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_name) = bb_has_abnormal_pred (bb);
      }
  
!   add_new_name_mapping (new_name, old_name);
  
    /* For the benefit of passes that will be updating the SSA form on
       their own, set the current reaching definition of OLD_NAME to be
       NEW_NAME.  */
    get_ssa_name_ann (old_name)->info.current_def = new_name;
  
!   timevar_pop (TV_TREE_SSA_INCREMENTAL);
  
!   return new_name;
  }
  
  
*************** insert_updated_phi_nodes_for (tree var,
*** 3056,3068 ****
        frontier of the blocks where each of NEW_SSA_NAMES are defined.
  
     The mapping between OLD_SSA_NAMES and NEW_SSA_NAMES is setup by
!    calling register_new_name_mapping for every pair of names that the
     caller wants to replace.
  
!    The caller identifies the new names that have been inserted and the
!    names that need to be replaced by calling register_new_name_mapping
!    for every pair <NEW, OLD>.  Note that the function assumes that the
!    new names have already been inserted in the IL.
  
     For instance, given the following code:
  
--- 3050,3062 ----
        frontier of the blocks where each of NEW_SSA_NAMES are defined.
  
     The mapping between OLD_SSA_NAMES and NEW_SSA_NAMES is setup by
!    calling create_new_def_for to create new defs for names that the
     caller wants to replace.
  
!    The caller cretaes the new names to be inserted and the names that need
!    to be replaced by calling create_new_def_for for each old definition
!    to be replaced.  Note that the function assumes that the
!    new defining statement has already been inserted in the IL.
  
     For instance, given the following code:
  
Index: gcc/tree-vrp.c
===================================================================
*** gcc/tree-vrp.c	(revision 190525)
--- gcc/tree-vrp.c	(working copy)
*************** debug_all_value_ranges (void)
*** 4152,4184 ****
  static gimple
  build_assert_expr_for (tree cond, tree v)
  {
!   tree n;
    gimple assertion;
  
!   gcc_assert (TREE_CODE (v) == SSA_NAME);
!   n = duplicate_ssa_name (v, NULL);
  
!   if (COMPARISON_CLASS_P (cond))
!     {
!       tree a = build2 (ASSERT_EXPR, TREE_TYPE (v), v, cond);
!       assertion = gimple_build_assign (n, a);
!     }
!   else if (TREE_CODE (cond) == SSA_NAME)
!     {
!       /* Given V, build the assignment N = true.  */
!       gcc_assert (v == cond);
!       assertion = gimple_build_assign (n, boolean_true_node);
!     }
!   else
!     gcc_unreachable ();
! 
!   SSA_NAME_DEF_STMT (n) = assertion;
  
    /* The new ASSERT_EXPR, creates a new SSA name that replaces the
!      operand of the ASSERT_EXPR. Register the new name and the old one
!      in the replacement table so that we can fix the SSA web after
!      adding all the ASSERT_EXPRs.  */
!   register_new_name_mapping (n, v);
  
    return assertion;
  }
--- 4152,4171 ----
  static gimple
  build_assert_expr_for (tree cond, tree v)
  {
!   tree a, n;
    gimple assertion;
  
!   gcc_assert (TREE_CODE (v) == SSA_NAME
! 	      && COMPARISON_CLASS_P (cond));
  
!   a = build2 (ASSERT_EXPR, TREE_TYPE (v), v, cond);
!   assertion = gimple_build_assign (NULL_TREE, a);
  
    /* The new ASSERT_EXPR, creates a new SSA name that replaces the
!      operand of the ASSERT_EXPR.  Create it so the new name and the old one
!      are registered in the replacement table so that we can fix the SSA web
!      after adding all the ASSERT_EXPRs.  */
!   n = create_new_def_for (v, assertion, NULL);
  
    return assertion;
  }