Add future_cost placeholder.
Currently, the -mcpu=future uses the power9 costs. This patch separates out
the cost to a separate structure so that in the future we can tweak the costs
as needed.
I have bootstraped versions of this patch multiple times on a power8 little
endian system. Can I check this into the FSF trunk?
2019-08-01 Michael Meissner <meiss...@linux.ibm.com>
* config/rs6000/rs6000.c (future_cost): Add separate cost
structure for a 'future' machine.
(rs6000_option_override_internal): If -mcpu=future, use the future
costs instead of power9.
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 273954)
+++ gcc/config/rs6000/rs6000.c (working copy)
@@ -1079,6 +1079,27 @@ struct processor_costs power9_cost = {
COSTS_N_INSNS (3), /* SF->DF convert */
};
+/* Instruction costs on FUTURE processors. At present, this is a place holder,
+ until more accurate information can be provided. */
+static const
+struct processor_costs future_cost = {
+ COSTS_N_INSNS (3), /* mulsi */
+ COSTS_N_INSNS (3), /* mulsi_const */
+ COSTS_N_INSNS (3), /* mulsi_const9 */
+ COSTS_N_INSNS (3), /* muldi */
+ COSTS_N_INSNS (8), /* divsi */
+ COSTS_N_INSNS (12), /* divdi */
+ COSTS_N_INSNS (3), /* fp */
+ COSTS_N_INSNS (3), /* dmul */
+ COSTS_N_INSNS (13), /* sdiv */
+ COSTS_N_INSNS (18), /* ddiv */
+ 128, /* cache line size */
+ 32, /* l1 cache */
+ 512, /* l2 cache */
+ 8, /* prefetch streams */
+ COSTS_N_INSNS (3), /* SF->DF convert */
+};
+
/* Instruction costs on POWER A2 processors. */
static const
struct processor_costs ppca2_cost = {
@@ -4487,10 +4508,13 @@ rs6000_option_override_internal (bool gl
break;
case PROCESSOR_POWER9:
- case PROCESSOR_FUTURE:
rs6000_cost = &power9_cost;
break;
+ case PROCESSOR_FUTURE:
+ rs6000_cost = &future_cost;
+ break;
+
case PROCESSOR_PPCA2:
rs6000_cost = &ppca2_cost;
break;
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meiss...@linux.ibm.com, phone: +1 (978) 899-4797
