The following patch solves a spill problem for
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90706
There are still redundant moves which should be removed to solve PR.
I'll continue my work on this in Jan.
commit 12abd5a7d13209f79664ea603b3f3517f71b8c4f
Author: Vladimir N. Makarov <vmaka...@redhat.com>
Date: Thu Dec 15 14:11:05 2022 -0500
IRA: Check that reg classes contain a hard reg of given mode in reg move cost calculation
IRA calculates wrong AVR costs for moving general hard regs of SFmode. To
calculate the costs we did not exclude sub-classes which do not contain
hard regs of given mode. This was the reason for spilling a pseudo in the
PR. The patch fixes this.
PR rtl-optimization/90706
gcc/ChangeLog:
* ira-costs.cc: Include print-rtl.h.
(record_reg_classes, scan_one_insn): Add code to print debug info.
* ira.cc (ira_init_register_move_cost): Check that at least one hard
reg of the mode are in the class contents to calculate the
register move costs.
gcc/testsuite/ChangeLog:
* gcc.target/avr/pr90706.c: New.
diff --git a/gcc/ira-costs.cc b/gcc/ira-costs.cc
index 964c94a06ef..732a0edd4c1 100644
--- a/gcc/ira-costs.cc
+++ b/gcc/ira-costs.cc
@@ -34,6 +34,7 @@ along with GCC; see the file COPYING3. If not see
#include "ira-int.h"
#include "addresses.h"
#include "reload.h"
+#include "print-rtl.h"
/* The flags is set up every time when we calculate pseudo register
classes through function ira_set_pseudo_classes. */
@@ -503,6 +504,18 @@ record_reg_classes (int n_alts, int n_ops, rtx *ops,
int insn_allows_mem[MAX_RECOG_OPERANDS];
move_table *move_in_cost, *move_out_cost;
short (*mem_cost)[2];
+ const char *p;
+
+ if (ira_dump_file != NULL && internal_flag_ira_verbose > 5)
+ {
+ fprintf (ira_dump_file, " Processing insn %u", INSN_UID (insn));
+ if (INSN_CODE (insn) >= 0
+ && (p = get_insn_name (INSN_CODE (insn))) != NULL)
+ fprintf (ira_dump_file, " {%s}", p);
+ fprintf (ira_dump_file, " (freq=%d)\n",
+ REG_FREQ_FROM_BB (BLOCK_FOR_INSN (insn)));
+ dump_insn_slim (ira_dump_file, insn);
+ }
for (i = 0; i < n_ops; i++)
insn_allows_mem[i] = 0;
@@ -526,6 +539,21 @@ record_reg_classes (int n_alts, int n_ops, rtx *ops,
continue;
}
+ if (ira_dump_file != NULL && internal_flag_ira_verbose > 5)
+ {
+ fprintf (ira_dump_file, " Alt %d:", alt);
+ for (i = 0; i < n_ops; i++)
+ {
+ p = constraints[i];
+ if (*p == '\0')
+ continue;
+ fprintf (ira_dump_file, " (%d) ", i);
+ for (; *p != '\0' && *p != ',' && *p != '#'; p++)
+ fputc (*p, ira_dump_file);
+ }
+ fprintf (ira_dump_file, "\n");
+ }
+
for (i = 0; i < n_ops; i++)
{
unsigned char c;
@@ -593,12 +621,16 @@ record_reg_classes (int n_alts, int n_ops, rtx *ops,
register, this alternative can't be used. */
if (classes[j] == NO_REGS)
- alt_fail = 1;
- /* Otherwise, add to the cost of this alternative
- the cost to copy the other operand to the hard
- register used for this operand. */
+ {
+ alt_fail = 1;
+ }
else
- alt_cost += copy_cost (ops[j], mode, classes[j], 1, NULL);
+ /* Otherwise, add to the cost of this alternative the cost
+ to copy the other operand to the hard register used for
+ this operand. */
+ {
+ alt_cost += copy_cost (ops[j], mode, classes[j], 1, NULL);
+ }
}
else
{
@@ -1021,18 +1053,45 @@ record_reg_classes (int n_alts, int n_ops, rtx *ops,
for (i = 0; i < n_ops; i++)
if (REG_P (ops[i]) && REGNO (ops[i]) >= FIRST_PSEUDO_REGISTER)
{
+ int old_cost;
+ bool cost_change_p = false;
struct costs *pp = op_costs[i], *qq = this_op_costs[i];
int *pp_costs = pp->cost, *qq_costs = qq->cost;
int scale = 1 + (recog_data.operand_type[i] == OP_INOUT);
cost_classes_t cost_classes_ptr
= regno_cost_classes[REGNO (ops[i])];
- pp->mem_cost = MIN (pp->mem_cost,
+ old_cost = pp->mem_cost;
+ pp->mem_cost = MIN (old_cost,
(qq->mem_cost + op_cost_add) * scale);
+ if (ira_dump_file != NULL && internal_flag_ira_verbose > 5
+ && pp->mem_cost < old_cost)
+ {
+ cost_change_p = true;
+ fprintf (ira_dump_file, " op %d(r=%u) new costs MEM:%d",
+ i, REGNO(ops[i]), pp->mem_cost);
+ }
for (k = cost_classes_ptr->num - 1; k >= 0; k--)
- pp_costs[k]
- = MIN (pp_costs[k], (qq_costs[k] + op_cost_add) * scale);
+ {
+ old_cost = pp_costs[k];
+ pp_costs[k]
+ = MIN (old_cost, (qq_costs[k] + op_cost_add) * scale);
+ if (ira_dump_file != NULL && internal_flag_ira_verbose > 5
+ && pp_costs[k] < old_cost)
+ {
+ if (!cost_change_p)
+ fprintf (ira_dump_file, " op %d(r=%u) new costs",
+ i, REGNO(ops[i]));
+ cost_change_p = true;
+ fprintf (ira_dump_file, " %s:%d",
+ reg_class_names[cost_classes_ptr->classes[k]],
+ pp_costs[k]);
+ }
+ }
+ if (ira_dump_file != NULL && internal_flag_ira_verbose > 5
+ && cost_change_p)
+ fprintf (ira_dump_file, "\n");
}
}
@@ -1506,6 +1565,18 @@ scan_one_insn (rtx_insn *insn)
record_operand_costs (insn, pref);
+ if (ira_dump_file != NULL && internal_flag_ira_verbose > 5)
+ {
+ const char *p;
+ fprintf (ira_dump_file, " Final costs after insn %u", INSN_UID (insn));
+ if (INSN_CODE (insn) >= 0
+ && (p = get_insn_name (INSN_CODE (insn))) != NULL)
+ fprintf (ira_dump_file, " {%s}", p);
+ fprintf (ira_dump_file, " (freq=%d)\n",
+ REG_FREQ_FROM_BB (BLOCK_FOR_INSN (insn)));
+ dump_insn_slim (ira_dump_file, insn);
+ }
+
/* Now add the cost for each operand to the total costs for its
allocno. */
for (i = 0; i < recog_data.n_operands; i++)
@@ -1521,7 +1592,7 @@ scan_one_insn (rtx_insn *insn)
struct costs *q = op_costs[i];
int *p_costs = p->cost, *q_costs = q->cost;
cost_classes_t cost_classes_ptr = regno_cost_classes[regno];
- int add_cost;
+ int add_cost = 0;
/* If the already accounted for the memory "cost" above, don't
do so again. */
@@ -1533,6 +1604,11 @@ scan_one_insn (rtx_insn *insn)
else
p->mem_cost += add_cost;
}
+ if (ira_dump_file != NULL && internal_flag_ira_verbose > 5)
+ {
+ fprintf (ira_dump_file, " op %d(r=%u) MEM:%d(+%d)",
+ i, REGNO(op), p->mem_cost, add_cost);
+ }
for (k = cost_classes_ptr->num - 1; k >= 0; k--)
{
add_cost = q_costs[k];
@@ -1540,7 +1616,15 @@ scan_one_insn (rtx_insn *insn)
p_costs[k] = INT_MAX;
else
p_costs[k] += add_cost;
+ if (ira_dump_file != NULL && internal_flag_ira_verbose > 5)
+ {
+ fprintf (ira_dump_file, " %s:%d(+%d)",
+ reg_class_names[cost_classes_ptr->classes[k]],
+ p_costs[k], add_cost);
+ }
}
+ if (ira_dump_file != NULL && internal_flag_ira_verbose > 5)
+ fprintf (ira_dump_file, "\n");
}
}
return insn;
diff --git a/gcc/ira.cc b/gcc/ira.cc
index d28a67b2546..cb4bfca739d 100644
--- a/gcc/ira.cc
+++ b/gcc/ira.cc
@@ -1627,14 +1627,22 @@ ira_init_register_move_cost (machine_mode mode)
*p2 != LIM_REG_CLASSES; p2++)
if (ira_class_hard_regs_num[*p2] > 0
&& (ira_reg_class_max_nregs[*p2][mode]
- <= ira_class_hard_regs_num[*p2]))
+ <= ira_class_hard_regs_num[*p2])
+ && hard_reg_set_intersect_p (ok_regs,
+ reg_class_contents[cl1])
+ && hard_reg_set_intersect_p (ok_regs,
+ reg_class_contents[*p2]))
cost = MAX (cost, ira_register_move_cost[mode][cl1][*p2]);
for (p1 = ®_class_subclasses[cl1][0];
*p1 != LIM_REG_CLASSES; p1++)
if (ira_class_hard_regs_num[*p1] > 0
&& (ira_reg_class_max_nregs[*p1][mode]
- <= ira_class_hard_regs_num[*p1]))
+ <= ira_class_hard_regs_num[*p1])
+ && hard_reg_set_intersect_p (ok_regs,
+ reg_class_contents[cl2])
+ && hard_reg_set_intersect_p (ok_regs,
+ reg_class_contents[*p1]))
cost = MAX (cost, ira_register_move_cost[mode][*p1][cl2]);
ira_assert (cost <= 65535);
diff --git a/gcc/testsuite/gcc.target/avr/pr90706.c b/gcc/testsuite/gcc.target/avr/pr90706.c
new file mode 100644
index 00000000000..4b9bcbe1152
--- /dev/null
+++ b/gcc/testsuite/gcc.target/avr/pr90706.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-Os" } */
+
+unsigned char check(float x)
+{
+ return (0.0 < x);
+}
+ /* { dg-final { scan-assembler-not "ldd" } } */
+ /* { dg-final { scan-assembler-not "std" } } */
