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tree-ssa-dom.c (cprop_into_successor_phis): Remove code to find the index of a PHI argument.

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* tree-ssa-dom.c (cprop_into_successor_phis): Remove code to
	find the index of a PHI argument.  Use e->dest_idx instead.
	Replace hint with index.

From-SVN: r91166
This commit is contained in:
Kazu Hirata 2004-11-24 15:15:12 +00:00 committed by Kazu Hirata
parent 8a7228ee92
commit 358804e741
2 changed files with 10 additions and 35 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2004-11-23 Kazu Hirata <kazu@cs.umass.edu>
* tree-ssa-dom.c (cprop_into_successor_phis): Remove code to
find the index of a PHI argument. Use e->dest_idx instead.
Replace hint with index.
2004-11-24 Diego Novillo <dnovillo@redhat.com>
* tree-ssa-alias.c (merge_pointed_to_info): Fix comment

39
gcc/tree-ssa-dom.c
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@ -2290,8 +2290,7 @@ cprop_into_successor_phis (basic_block bb, bitmap nonzero_vars)
FOR_EACH_EDGE (e, ei, bb->succs)
{
tree phi;
int phi_num_args;
int hint;
int index;
/* If this is an abnormal edge, then we do not want to copy propagate
into the PHI alternative associated with this edge. */
@ -2302,46 +2301,16 @@ cprop_into_successor_phis (basic_block bb, bitmap nonzero_vars)
if (! phi)
continue;
/* There is no guarantee that for any two PHI nodes in a block that
the phi alternative associated with a particular edge will be
at the same index in the phi alternative array.
However, it is very likely they will be the same. So we keep
track of the index of the alternative where we found the edge in
the previous phi node and check that index first in the next
phi node. If that hint fails, then we actually search all
the entries. */
phi_num_args = PHI_NUM_ARGS (phi);
hint = phi_num_args;
index = e->dest_idx;
for ( ; phi; phi = PHI_CHAIN (phi))
{
int i;
tree new;
use_operand_p orig_p;
tree orig;
/* If the hint is valid (!= phi_num_args), see if it points
us to the desired phi alternative. */
if (hint != phi_num_args && PHI_ARG_EDGE (phi, hint) == e)
;
else
{
/* The hint was either invalid or did not point to the
correct phi alternative. Search all the alternatives
for the correct one. Update the hint. */
for (i = 0; i < phi_num_args; i++)
if (PHI_ARG_EDGE (phi, i) == e)
break;
hint = i;
}
/* If we did not find the proper alternative, then something is
horribly wrong. */
gcc_assert (hint != phi_num_args);
/* The alternative may be associated with a constant, so verify
it is an SSA_NAME before doing anything with it. */
orig_p = PHI_ARG_DEF_PTR (phi, hint);
orig_p = PHI_ARG_DEF_PTR (phi, index);
orig = USE_FROM_PTR (orig_p);
if (TREE_CODE (orig) != SSA_NAME)
continue;
@ -2349,7 +2318,7 @@ cprop_into_successor_phis (basic_block bb, bitmap nonzero_vars)
/* If the alternative is known to have a nonzero value, record
that fact in the PHI node itself for future use. */
if (bitmap_bit_p (nonzero_vars, SSA_NAME_VERSION (orig)))
PHI_ARG_NONZERO (phi, hint) = true;
PHI_ARG_NONZERO (phi, index) = true;
/* If we have *ORIG_P in our constant/copy table, then replace
ORIG_P with its value in our constant/copy table. */