Hi,
As mentioned in the PR, the original fix could wrongly delete insns,
which e.g. shows in the new gcc.dg/atomic/stdatomic-flag.c failures.
Thus, add some more checks to make sure that it's safe to delete it.
Tested with
make -k check RUNTESTFLAGS="--target_board=sh-sim\{-m4/-ml,-m4/-mb}"
committed as r218200.
Cheers,
Oleg
gcc/ChangeLog:
PR target/63986
PR target/51244
* config/sh/sh.c (sh_unspec_insn_p,
sh_insn_operands_modified_between_p): New functions.
(sh_split_movrt_negc_to_movt_xor): Do not delete insn if its operands
are modified or if it has side effects, may trap or is volatile.
Index: gcc/config/sh/sh.c
===================================================================
--- gcc/config/sh/sh.c (revision 218189)
+++ gcc/config/sh/sh.c (working copy)
@@ -13503,6 +13503,47 @@
Manual insn combine support code.
*/
+/* Return true if the specified insn contains any UNSPECs or
+ UNSPEC_VOLATILEs. */
+static bool
+sh_unspec_insn_p (rtx_insn* insn)
+{
+ bool result = false;
+
+ struct note_uses_func
+ {
+ static void
+ func (rtx* x, void* data)
+ {
+ if (GET_CODE (*x) == UNSPEC || GET_CODE (*x) == UNSPEC_VOLATILE)
+ *(static_cast<bool*> (data)) = true;
+ }
+ };
+
+ note_uses (&PATTERN (insn), note_uses_func::func, &result);
+ return result;
+}
+
+/* Return true if the register operands of the specified insn are modified
+ between the specified from and to insns (exclusive of those two). */
+static bool
+sh_insn_operands_modified_between_p (rtx_insn* operands_insn,
+ const rtx_insn* from,
+ const rtx_insn* to)
+{
+ /* FIXME: Return true for multiple sets for now. */
+ rtx s = single_set (operands_insn);
+ if (s == NULL_RTX)
+ return true;
+
+ subrtx_iterator::array_type array;
+ FOR_EACH_SUBRTX (i, array, SET_SRC (s), ALL)
+ if ((REG_P (*i) || SUBREG_P (*i)) && reg_set_between_p (*i, from, to))
+ return true;
+
+ return false;
+}
+
/* Given an op rtx and an insn, try to find out whether the result of the
specified op consists only of logical operations on T bit stores. */
bool
@@ -13598,7 +13639,14 @@
if (t_before_negc.set_rtx != NULL_RTX && t_after_negc.set_rtx != NULL_RTX
&& rtx_equal_p (t_before_negc.set_rtx, t_after_negc.set_rtx)
- && !reg_used_between_p (get_t_reg_rtx (), curr_insn, t_after_negc.insn))
+ && !reg_used_between_p (get_t_reg_rtx (), curr_insn, t_after_negc.insn)
+ && !sh_insn_operands_modified_between_p (t_before_negc.insn,
+ t_before_negc.insn,
+ t_after_negc.insn)
+ && !sh_unspec_insn_p (t_after_negc.insn)
+ && !volatile_insn_p (PATTERN (t_after_negc.insn))
+ && !side_effects_p (PATTERN (t_after_negc.insn))
+ && !may_trap_or_fault_p (PATTERN (t_after_negc.insn)))
{
emit_insn (gen_movrt_xor (operands[0], get_t_reg_rtx ()));
set_insn_deleted (t_after_negc.insn);
