The following patch fixes
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92796
The patch was successfully bootstrapped and tested on x86-64.
Committed as r279204
Index: ChangeLog
===================================================================
--- ChangeLog (revision 279200)
+++ ChangeLog (working copy)
@@ -1,3 +1,18 @@
+2019-12-10 Vladimir Makarov <vmaka...@redhat.com>
+
+ PR rtl-optimization/92796
+ * lra-int.h (lra_risky_transformations_p): Rename to
+ check_and_force_assignment_correctness_p.
+ * lra-assigns.c: Ditto.
+ (lra_assign): Reset check_and_force_assignment_correctness_p.
+ * lra-constraints.c (lra_risky_transformations_p): Rename to
+ check_and_force_assignment_correctness_p.
+ (lra_constraints): Set up check_and_force_assignment_correctness_p
+ only for the 1st sub-pass.
+ * lra-eliminations.c (process_insn_for_elimination): Set up
+ check_and_force_assignment_correctness_p if the insn chnaged its
+ code.
+
2019-12-10 Jakub Jelinek <ja...@redhat.com>
PR rtl-optimization/92882
Index: lra-assigns.c
===================================================================
--- lra-assigns.c (revision 278608)
+++ lra-assigns.c (working copy)
@@ -1131,7 +1131,7 @@ static int *sorted_pseudos;
/* The constraints pass is allowed to create equivalences between
pseudos that make the current allocation "incorrect" (in the sense
that pseudos are assigned to hard registers from their own conflict
- sets). The global variable lra_risky_transformations_p says
+ sets). The global variable check_and_force_assignment_correctness_p says
whether this might have happened.
Process pseudos assigned to hard registers (less frequently used
@@ -1152,7 +1152,7 @@ setup_live_pseudos_and_spill_after_risky
bitmap_iterator bi;
int max_regno = max_reg_num ();
- if (! lra_risky_transformations_p)
+ if (! check_and_force_assignment_correctness_p)
{
for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
if (reg_renumber[i] >= 0 && lra_reg_info[i].nrefs > 0)
@@ -1690,6 +1690,8 @@ lra_assign (bool &fails_p)
internal_error
("maximum number of LRA assignment passes is achieved (%d)",
LRA_MAX_ASSIGNMENT_ITERATION_NUMBER);
+ /* Reset the assignment correctness flag: */
+ check_and_force_assignment_correctness_p = false;
return no_spills_p;
}
Index: lra-constraints.c
===================================================================
--- lra-constraints.c (revision 278608)
+++ lra-constraints.c (working copy)
@@ -4665,11 +4665,14 @@ loc_equivalence_callback (rtx loc, const
/* The current iteration number of this LRA pass. */
int lra_constraint_iter;
-/* True if we substituted equiv which needs checking register
- allocation correctness because the equivalent value contains
- allocatable hard registers or when we restore multi-register
- pseudo. */
-bool lra_risky_transformations_p;
+/* True if we should during assignment sub-pass check assignment
+ correctness for all pseudos and spill some of them to correct
+ conflicts. It can be necessary when we substitute equiv which
+ needs checking register allocation correctness because the
+ equivalent value contains allocatable hard registers, or when we
+ restore multi-register pseudo, or when we change the insn code and
+ its operand became INOUT operand when it was IN one before. */
+bool check_and_force_assignment_correctness_p;
/* Return true if REGNO is referenced in more than one block. */
static bool
@@ -4811,14 +4814,14 @@ lra_constraints (bool first_p)
changed_p = false;
if (pic_offset_table_rtx
&& REGNO (pic_offset_table_rtx) >= FIRST_PSEUDO_REGISTER)
- lra_risky_transformations_p = true;
- else
+ check_and_force_assignment_correctness_p = true;
+ else if (first_p)
/* On the first iteration we should check IRA assignment
correctness. In rare cases, the assignments can be wrong as
early clobbers operands are ignored in IRA or usages of
paradoxical sub-registers are not taken into account by
IRA. */
- lra_risky_transformations_p = first_p;
+ check_and_force_assignment_correctness_p = true;
new_insn_uid_start = get_max_uid ();
new_regno_start = first_p ? lra_constraint_new_regno_start : max_reg_num ();
/* Mark used hard regs for target stack size calulations. */
@@ -4994,7 +4997,7 @@ lra_constraints (bool first_p)
dump_insn_slim (lra_dump_file, curr_insn);
}
if (contains_reg_p (x, true, false))
- lra_risky_transformations_p = true;
+ check_and_force_assignment_correctness_p = true;
lra_set_insn_deleted (curr_insn);
continue;
}
@@ -5507,7 +5510,7 @@ need_for_split_p (HARD_REG_SET potential
/* Don't split call clobbered hard regs living through
calls, otherwise we might have a check problem in the
assign sub-pass as in the most cases (exception is a
- situation when lra_risky_transformations_p value is
+ situation when check_and_force_assignment_correctness_p value is
true) the assign pass assumes that all pseudos living
through calls are assigned to call saved hard regs. */
&& (regno >= FIRST_PSEUDO_REGISTER
@@ -5799,7 +5802,7 @@ split_reg (bool before_p, int original_r
sub-register levels, LRA do this on pseudos level right now and
this discrepancy may create allocation conflicts after
splitting. */
- lra_risky_transformations_p = true;
+ check_and_force_assignment_correctness_p = true;
if (lra_dump_file != NULL)
fprintf (lra_dump_file,
" ))))))))))))))))))))))))))))))))))))))))))))))))\n");
@@ -6561,7 +6564,7 @@ inherit_in_ebb (rtx_insn *head, rtx_insn
before_p, curr_insn, max_uid))
{
if (reg->subreg_p)
- lra_risky_transformations_p = true;
+ check_and_force_assignment_correctness_p = true;
change_p = true;
/* Invalidate. */
usage_insns[src_regno].check = 0;
Index: lra-eliminations.c
===================================================================
--- lra-eliminations.c (revision 278608)
+++ lra-eliminations.c (working copy)
@@ -1311,6 +1311,11 @@ process_insn_for_elimination (rtx_insn *
if (icode >= 0 && icode != INSN_CODE (insn))
{
+ if (INSN_CODE (insn) >= 0)
+ /* Insn code is changed. It may change its operand type
+ from IN to INOUT. Inform the subsequent assignment
+ subpass about this situation. */
+ check_and_force_assignment_correctness_p = true;
INSN_CODE (insn) = icode;
lra_update_insn_recog_data (insn);
}
Index: lra-int.h
===================================================================
--- lra-int.h (revision 278413)
+++ lra-int.h (working copy)
@@ -337,7 +337,7 @@ extern void lra_init_equiv (void);
extern int lra_constraint_offset (int, machine_mode);
extern int lra_constraint_iter;
-extern bool lra_risky_transformations_p;
+extern bool check_and_force_assignment_correctness_p;
extern int lra_inheritance_iter;
extern int lra_undo_inheritance_iter;
extern bool lra_constrain_insn (rtx_insn *);
Index: testsuite/ChangeLog
===================================================================
--- testsuite/ChangeLog (revision 279200)
+++ testsuite/ChangeLog (working copy)
@@ -1,3 +1,8 @@
+2019-12-10 Vladimir Makarov <vmaka...@redhat.com>
+
+ PR rtl-optimization/92796
+ * gcc.target/powerpc/pr92796.c: New test.
+
2019-12-10 Jakub Jelinek <ja...@redhat.com>
PR rtl-optimization/92882
Index: testsuite/gcc.target/powerpc/pr92796.c
===================================================================
--- testsuite/gcc.target/powerpc/pr92796.c (nonexistent)
+++ testsuite/gcc.target/powerpc/pr92796.c (working copy)
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fstack-protector-strong -mcpu=power8" } */
+
+typedef union
+{
+ __ieee128 a;
+ int b;
+} c;
+
+__ieee128
+d (__ieee128 x)
+{
+ __ieee128 g;
+ c h;
+ h.a = x;
+ g = h.b & 5;
+ h.b = g;
+ if (g)
+ return x - x;
+ return h.a;
+}
