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[PATCH, committed] Backport PR87473 fix to GCC 7
- From: Bill Schmidt <wschmidt at linux dot ibm dot com>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Fri, 26 Oct 2018 14:46:06 -0500
- Subject: [PATCH, committed] Backport PR87473 fix to GCC 7
Committed the backport as follows (some slight changes between versions were required):
[gcc]
2018-10-26 Bill Schmidt <wschmidt@linux.ibm.com>
Backport from mainline
2018-10-19 Bill Schmidt <wschmidt@linux.ibm.com>
PR tree-optimization/87473
* gimple-ssa-strength-reduction.c (record_phi_increments): For
phi arguments identical to the base expression of the phi
candidate, record a phi-adjust increment of zero minus the index
expression of the hidden basis.
(phi_incr_cost): For phi arguments identical to the base
expression of the phi candidate, the difference to compare against
the increment is zero minus the index expression of the hidden
basis, and there is no potential savings from replacing the (phi)
statement.
(ncd_with_phi): For phi arguments identical to the base expression
of the phi candidate, the difference to compare against the
increment is zero minus the index expression of the hidden basis.
(all_phi_incrs_profitable): For phi arguments identical to the
base expression of the phi candidate, the increment to be checked
for profitability is zero minus the index expression of the hidden
basis.
[gcc/testsuite]
2018-10-26 Bill Schmidt <wschmidt@linux.ibm.com>
Backport from mainline
2018-10-19 Bill Schmidt <wschmidt@linux.ibm.com>
PR tree-optimization/87473
* gcc.c-torture/compile/pr87473.c: New file.
Index: gcc/ChangeLog
===================================================================
--- gcc/ChangeLog (revision 265546)
+++ gcc/ChangeLog (revision 265547)
@@ -1,3 +1,26 @@
+2018-10-26 Bill Schmidt <wschmidt@linux.ibm.com>
+
+ Backport from mainline
+ 2018-10-19 Bill Schmidt <wschmidt@linux.ibm.com>
+
+ PR tree-optimization/87473
+ * gimple-ssa-strength-reduction.c (record_phi_increments): For
+ phi arguments identical to the base expression of the phi
+ candidate, record a phi-adjust increment of zero minus the index
+ expression of the hidden basis.
+ (phi_incr_cost): For phi arguments identical to the base
+ expression of the phi candidate, the difference to compare against
+ the increment is zero minus the index expression of the hidden
+ basis, and there is no potential savings from replacing the (phi)
+ statement.
+ (ncd_with_phi): For phi arguments identical to the base expression
+ of the phi candidate, the difference to compare against the
+ increment is zero minus the index expression of the hidden basis.
+ (all_phi_incrs_profitable): For phi arguments identical to the
+ base expression of the phi candidate, the increment to be checked
+ for profitability is zero minus the index expression of the hidden
+ basis.
+
2018-10-19 Andreas Krebbel <krebbel@linux.ibm.com>
Backport from mainline
Index: gcc/testsuite/gcc.c-torture/compile/pr87473.c
===================================================================
--- gcc/testsuite/gcc.c-torture/compile/pr87473.c (nonexistent)
+++ gcc/testsuite/gcc.c-torture/compile/pr87473.c (revision 265547)
@@ -0,0 +1,19 @@
+/* PR87473: SLSR ICE on hidden basis with |increment| > 1. */
+/* { dg-additional-options "-fno-tree-ch" } */
+
+void
+t6 (int qz, int wh)
+{
+ int jl = wh;
+
+ while (1.0 / 0 < 1)
+ {
+ qz = wh * (wh + 2);
+
+ while (wh < 1)
+ jl = 0;
+ }
+
+ while (qz < 1)
+ qz = jl * wh;
+}
Index: gcc/testsuite/ChangeLog
===================================================================
--- gcc/testsuite/ChangeLog (revision 265546)
+++ gcc/testsuite/ChangeLog (revision 265547)
@@ -1,3 +1,11 @@
+2018-10-26 Bill Schmidt <wschmidt@linux.ibm.com>
+
+ Backport from mainline
+ 2018-10-19 Bill Schmidt <wschmidt@linux.ibm.com>
+
+ PR tree-optimization/87473
+ * gcc.c-torture/compile/pr87473.c: New file.
+
2018-10-23 Tom de Vries <tdevries@suse.de>
backport from trunk:
Index: gcc/gimple-ssa-strength-reduction.c
===================================================================
--- gcc/gimple-ssa-strength-reduction.c (revision 265546)
+++ gcc/gimple-ssa-strength-reduction.c (revision 265547)
@@ -2666,17 +2666,23 @@ record_phi_increments (slsr_cand_t basis, gimple *
for (i = 0; i < gimple_phi_num_args (phi); i++)
{
tree arg = gimple_phi_arg_def (phi, i);
+ gimple *arg_def = SSA_NAME_DEF_STMT (arg);
- if (!operand_equal_p (arg, phi_cand->base_expr, 0))
+ if (gimple_code (arg_def) == GIMPLE_PHI)
+ record_phi_increments (basis, arg_def);
+ else
{
- gimple *arg_def = SSA_NAME_DEF_STMT (arg);
+ widest_int diff;
- if (gimple_code (arg_def) == GIMPLE_PHI)
- record_phi_increments (basis, arg_def);
+ if (operand_equal_p (arg, phi_cand->base_expr, 0))
+ {
+ diff = -basis->index;
+ record_increment (phi_cand, diff, PHI_ADJUST);
+ }
else
{
slsr_cand_t arg_cand = base_cand_from_table (arg);
- widest_int diff = arg_cand->index - basis->index;
+ diff = arg_cand->index - basis->index;
record_increment (arg_cand, diff, PHI_ADJUST);
}
}
@@ -2738,28 +2744,42 @@ phi_incr_cost (slsr_cand_t c, const widest_int &in
for (i = 0; i < gimple_phi_num_args (phi); i++)
{
tree arg = gimple_phi_arg_def (phi, i);
+ gimple *arg_def = SSA_NAME_DEF_STMT (arg);
- if (!operand_equal_p (arg, phi_cand->base_expr, 0))
+ if (gimple_code (arg_def) == GIMPLE_PHI)
{
- gimple *arg_def = SSA_NAME_DEF_STMT (arg);
-
- if (gimple_code (arg_def) == GIMPLE_PHI)
+ int feeding_savings = 0;
+ cost += phi_incr_cost (c, incr, arg_def, &feeding_savings);
+ if (has_single_use (gimple_phi_result (arg_def)))
+ *savings += feeding_savings;
+ }
+ else
+ {
+ widest_int diff;
+ slsr_cand_t arg_cand;
+
+ /* When the PHI argument is just a pass-through to the base
+ expression of the hidden basis, the difference is zero minus
+ the index of the basis. There is no potential savings by
+ eliminating a statement in this case. */
+ if (operand_equal_p (arg, phi_cand->base_expr, 0))
{
- int feeding_savings = 0;
- cost += phi_incr_cost (c, incr, arg_def, &feeding_savings);
- if (has_single_use (gimple_phi_result (arg_def)))
- *savings += feeding_savings;
+ arg_cand = (slsr_cand_t) NULL;
+ diff = -basis->index;
}
else
{
- slsr_cand_t arg_cand = base_cand_from_table (arg);
- widest_int diff = arg_cand->index - basis->index;
-
- if (incr == diff)
+ arg_cand = base_cand_from_table (arg);
+ diff = arg_cand->index - basis->index;
+ }
+
+ if (incr == diff)
+ {
+ tree basis_lhs = gimple_assign_lhs (basis->cand_stmt);
+ cost += add_cost (true, TYPE_MODE (TREE_TYPE (basis_lhs)));
+ if (arg_cand)
{
- tree basis_lhs = gimple_assign_lhs (basis->cand_stmt);
tree lhs = gimple_assign_lhs (arg_cand->cand_stmt);
- cost += add_cost (true, TYPE_MODE (TREE_TYPE (basis_lhs)));
if (has_single_use (lhs))
*savings += stmt_cost (arg_cand->cand_stmt, true);
}
@@ -3076,23 +3096,26 @@ ncd_with_phi (slsr_cand_t c, const widest_int &inc
for (i = 0; i < gimple_phi_num_args (phi); i++)
{
tree arg = gimple_phi_arg_def (phi, i);
+ gimple *arg_def = SSA_NAME_DEF_STMT (arg);
- if (!operand_equal_p (arg, phi_cand->base_expr, 0))
+ if (gimple_code (arg_def) == GIMPLE_PHI)
+ ncd = ncd_with_phi (c, incr, as_a <gphi *> (arg_def), ncd, where);
+ else
{
- gimple *arg_def = SSA_NAME_DEF_STMT (arg);
+ widest_int diff;
- if (gimple_code (arg_def) == GIMPLE_PHI)
- ncd = ncd_with_phi (c, incr, as_a <gphi *> (arg_def), ncd,
- where);
- else
+ if (operand_equal_p (arg, phi_cand->base_expr, 0))
+ diff = -basis->index;
+ else
{
slsr_cand_t arg_cand = base_cand_from_table (arg);
- widest_int diff = arg_cand->index - basis->index;
- basic_block pred = gimple_phi_arg_edge (phi, i)->src;
-
- if ((incr == diff) || (!address_arithmetic_p && incr == -diff))
- ncd = ncd_for_two_cands (ncd, pred, *where, NULL, where);
+ diff = arg_cand->index - basis->index;
}
+
+ basic_block pred = gimple_phi_arg_edge (phi, i)->src;
+
+ if ((incr == diff) || (!address_arithmetic_p && incr == -diff))
+ ncd = ncd_for_two_cands (ncd, pred, *where, NULL, where);
}
}
@@ -3358,49 +3381,52 @@ all_phi_incrs_profitable (slsr_cand_t c, gphi *phi
return false;
tree arg = gimple_phi_arg_def (phi, i);
+ gimple *arg_def = SSA_NAME_DEF_STMT (arg);
- if (!operand_equal_p (arg, phi_cand->base_expr, 0))
+ if (gimple_code (arg_def) == GIMPLE_PHI)
{
- gimple *arg_def = SSA_NAME_DEF_STMT (arg);
+ if (!all_phi_incrs_profitable (c, as_a <gphi *> (arg_def)))
+ return false;
+ }
+ else
+ {
+ int j;
+ widest_int increment;
- if (gimple_code (arg_def) == GIMPLE_PHI)
- {
- if (!all_phi_incrs_profitable (c, as_a <gphi *> (arg_def)))
- return false;
- }
+ if (operand_equal_p (arg, phi_cand->base_expr, 0))
+ increment = -basis->index;
else
{
- int j;
slsr_cand_t arg_cand = base_cand_from_table (arg);
- widest_int increment = arg_cand->index - basis->index;
+ increment = arg_cand->index - basis->index;
+ }
- if (!address_arithmetic_p && wi::neg_p (increment))
- increment = -increment;
+ if (!address_arithmetic_p && wi::neg_p (increment))
+ increment = -increment;
- j = incr_vec_index (increment);
+ j = incr_vec_index (increment);
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, " Conditional candidate %d, phi: ",
- c->cand_num);
- print_gimple_stmt (dump_file, phi, 0, 0);
- fputs (" increment: ", dump_file);
- print_decs (increment, dump_file);
- if (j < 0)
- fprintf (dump_file,
- "\n Not replaced; incr_vec overflow.\n");
- else {
- fprintf (dump_file, "\n cost: %d\n", incr_vec[j].cost);
- if (profitable_increment_p (j))
- fputs (" Replacing...\n", dump_file);
- else
- fputs (" Not replaced.\n", dump_file);
- }
- }
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " Conditional candidate %d, phi: ",
+ c->cand_num);
+ print_gimple_stmt (dump_file, phi, 0, 0);
+ fputs (" increment: ", dump_file);
+ print_decs (increment, dump_file);
+ if (j < 0)
+ fprintf (dump_file,
+ "\n Not replaced; incr_vec overflow.\n");
+ else {
+ fprintf (dump_file, "\n cost: %d\n", incr_vec[j].cost);
+ if (profitable_increment_p (j))
+ fputs (" Replacing...\n", dump_file);
+ else
+ fputs (" Not replaced.\n", dump_file);
+ }
+ }
- if (j < 0 || !profitable_increment_p (j))
- return false;
- }
+ if (j < 0 || !profitable_increment_p (j))
+ return false;
}
}