This patch removes copyprop passes run immediately after CCP. This
uncovered that I failed to implement copyprop properly for PHI nodes
(due to the "clever" using UNDEFINED as initial value to meet PHI
args into and me not wanting to enable optimistic copy-prop just yet).
Fixed together with the pass removal.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2015-04-23 Richard Biener <rguent...@suse.de>
* passes.def: Remove copy propagation passes run directly after CCP.
* tree-ssa-ccp.c (get_value_for_expr): Fall back to a COPY for
SSA names.
(ccp_visit_phi_node): Rework to handle first executable edge
specially.
Index: gcc/passes.def
===================================================================
--- gcc/passes.def (revision 222267)
+++ gcc/passes.def (working copy)
@@ -158,7 +158,6 @@ along with GCC; see the file COPYING3.
NEXT_PASS (pass_ccp);
/* After CCP we rewrite no longer addressed locals into SSA
form if possible. */
- NEXT_PASS (pass_copy_prop);
NEXT_PASS (pass_complete_unrolli);
NEXT_PASS (pass_phiprop);
NEXT_PASS (pass_forwprop);
@@ -210,7 +209,6 @@ along with GCC; see the file COPYING3.
NEXT_PASS (pass_ccp);
/* After CCP we rewrite no longer addressed locals into SSA
form if possible. */
- NEXT_PASS (pass_copy_prop);
NEXT_PASS (pass_cse_sincos);
NEXT_PASS (pass_optimize_bswap);
NEXT_PASS (pass_split_crit_edges);
Index: gcc/tree-ssa-ccp.c
===================================================================
*** gcc/tree-ssa-ccp.c (revision 222269)
--- gcc/tree-ssa-ccp.c (working copy)
*************** set_lattice_value (tree var, ccp_prop_va
*** 539,547 ****
if (old_val->lattice_val != new_val.lattice_val
|| (new_val.lattice_val == CONSTANT
&& (TREE_CODE (new_val.value) != TREE_CODE (old_val->value)
- || simple_cst_equal (new_val.value, old_val->value) != 1
|| (TREE_CODE (new_val.value) == INTEGER_CST
! && new_val.mask != old_val->mask))))
{
/* ??? We would like to delay creation of INTEGER_CSTs from
partially constants here. */
--- 539,552 ----
if (old_val->lattice_val != new_val.lattice_val
|| (new_val.lattice_val == CONSTANT
&& (TREE_CODE (new_val.value) != TREE_CODE (old_val->value)
|| (TREE_CODE (new_val.value) == INTEGER_CST
! && (new_val.mask != old_val->mask
! || (wi::bit_and_not (wi::to_widest (old_val->value),
! new_val.mask)
! != wi::bit_and_not (wi::to_widest (new_val.value),
! new_val.mask))))
! || (TREE_CODE (new_val.value) != INTEGER_CST
! && !operand_equal_p (new_val.value, old_val->value, 0)))))
{
/* ??? We would like to delay creation of INTEGER_CSTs from
partially constants here. */
*************** get_value_for_expr (tree expr, bool for_
*** 623,628 ****
--- 628,642 ----
&& val.lattice_val == CONSTANT
&& TREE_CODE (val.value) == ADDR_EXPR)
val = get_value_from_alignment (val.value);
+ /* Fall back to a copy value. */
+ if (!for_bits_p
+ && val.lattice_val == VARYING
+ && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (expr))
+ {
+ val.lattice_val = CONSTANT;
+ val.value = expr;
+ val.mask = -1;
+ }
}
else if (is_gimple_min_invariant (expr)
&& (!for_bits_p || TREE_CODE (expr) != ADDR_EXPR))
*************** static enum ssa_prop_result
*** 1068,1074 ****
ccp_visit_phi_node (gphi *phi)
{
unsigned i;
! ccp_prop_value_t *old_val, new_val;
if (dump_file && (dump_flags & TDF_DETAILS))
{
--- 1082,1088 ----
ccp_visit_phi_node (gphi *phi)
{
unsigned i;
! ccp_prop_value_t new_val;
if (dump_file && (dump_flags & TDF_DETAILS))
{
*************** ccp_visit_phi_node (gphi *phi)
*** 1076,1100 ****
print_gimple_stmt (dump_file, phi, 0, dump_flags);
}
! old_val = get_value (gimple_phi_result (phi));
! switch (old_val->lattice_val)
! {
! case VARYING:
! return SSA_PROP_VARYING;
!
! case CONSTANT:
! new_val = *old_val;
! break;
!
! case UNDEFINED:
! new_val.lattice_val = UNDEFINED;
! new_val.value = NULL_TREE;
! break;
!
! default:
! gcc_unreachable ();
! }
for (i = 0; i < gimple_phi_num_args (phi); i++)
{
/* Compute the meet operator over all the PHI arguments flowing
--- 1090,1100 ----
print_gimple_stmt (dump_file, phi, 0, dump_flags);
}
! new_val.lattice_val = UNDEFINED;
! new_val.value = NULL_TREE;
! new_val.mask = 0;
+ bool first = true;
for (i = 0; i < gimple_phi_num_args (phi); i++)
{
/* Compute the meet operator over all the PHI arguments flowing
*************** ccp_visit_phi_node (gphi *phi)
*** 1116,1122 ****
tree arg = gimple_phi_arg (phi, i)->def;
ccp_prop_value_t arg_val = get_value_for_expr (arg, false);
! ccp_lattice_meet (gimple_bb (phi), &new_val, &arg_val);
if (dump_file && (dump_flags & TDF_DETAILS))
{
--- 1116,1128 ----
tree arg = gimple_phi_arg (phi, i)->def;
ccp_prop_value_t arg_val = get_value_for_expr (arg, false);
! if (first)
! {
! new_val = arg_val;
! first = false;
! }
! else
! ccp_lattice_meet (gimple_bb (phi), &new_val, &arg_val);
if (dump_file && (dump_flags & TDF_DETAILS))
{
