> 2017-11-17 Daniel Cederman <ceder...@gaisler.com>
>
> * config/sparc/sparc.c (fpop_insn_p): New function.
> (sparc_do_work_around_errata): Insert NOP instructions to
> prevent sequences that could trigger the TN-0012 errata for
> GR712RC.
> (pass_work_around_errata::gate): Also test sparc_fix_gr712rc.
> * config/sparc/sparc.md (fix_gr712rc): New attribute.
> (in_branch_annul_delay): Prevent floating-point instructions
> in delay slot of annulled integer branch.
OK for mainline and 7 branch modulo the following nits:
> +/* True if floating-point instruction. */
> +
> +static int
> +fpop_insn_p (rtx_insn *insn)
'bool' instead of 'int'. "True if INSN is a floating-point instruction."
> +{
> + if ( GET_CODE (PATTERN (insn)) != SET)
> + return false;
No space before GET_CODE.
> /* We use a machine specific pass to enable workarounds for errata.
>
> We need to have the (essentially) final form of the insn stream in order
> @@ -970,11 +995,31 @@ sparc_do_work_around_errata (void)
> {
> bool insert_nop = false;
> rtx set;
> + rtx_insn *jump = 0;
>
> /* Look into the instruction in a delay slot. */
> if (NONJUMP_INSN_P (insn))
> if (rtx_sequence *seq = dyn_cast <rtx_sequence *> (PATTERN (insn)))
> - insn = seq->insn (1);
> + {
> + jump = seq->insn (0);
> + insn = seq->insn (1);
> + }
This should be changed into:
rtx_insn jump;
/* Look into the instruction in a delay slot. */
if (NONJUMP_INSN_P (insn)
&& (rtx_sequence *seq = dyn_cast <rtx_sequence *> (PATTERN (insn)))
{
jump = seq->insn (0);
insn = seq->insn (1);
}
else if (JUMP_P (insn))
jump = insn
else
jump = NULL_RTX;
and the block below simplified accordingly.
> + /* Place a NOP at the branch target of an integer branch if it is
> + a floating-point operation or a floating-point branch. */
> + if (sparc_fix_gr712rc
> + && (JUMP_P (insn) || jump)
> + && get_attr_branch_type (jump ? jump : insn) == BRANCH_TYPE_ICC)
> + {
> + rtx_insn *target;
> +
> + target = next_active_insn (JUMP_LABEL_AS_INSN (jump ? jump : insn));
rtx_insn *target = next_active_insn (JUMP_LABEL_AS_INSN (jump));
> /* Look for either of these two sequences:
>
> @@ -1303,7 +1348,8 @@ public:
> /* opt_pass methods: */
> virtual bool gate (function *)
> {
> - return sparc_fix_at697f || sparc_fix_ut699 || sparc_fix_b2bst;
> + return sparc_fix_at697f || sparc_fix_ut699 || sparc_fix_b2bst
> + || sparc_fix_gr712rc;
> }
"|| sparc_fix_gr712rc" lined up under sparc_fix_at697f.
> @@ -602,6 +615,10 @@
> (define_delay (eq_attr "type" "branch")
> [(eq_attr "in_branch_delay" "true") (nil) (eq_attr "in_branch_delay"
> "true")])
>
> +(define_delay (and (eq_attr "type" "branch") (eq_attr "branch_type" "icc"))
> + [(eq_attr "in_branch_delay" "true") (nil)
> + (eq_attr "in_branch_annul_delay" "true")])
> +
I think that we'd better keep the various define_delay's mutually exclusive.
--
Eric Botcazou
