Hello,
the attached patch corrects the costs calculation for AND / OR / XOR
operations that could be done with an 8 bit immediate value and R0.
The change doesn't seem to have an impact on the generated code but will
be (probably) required to fix PR 49263.
Tested with make -k check RUNTESTFLAGS="--target_board=sh-sim
\{-m2,-m2a-single,-m4-single,-m4a-single\}\{-mb,-ml\}" with no new
failures.
2011-09-21 Oleg Endo <oleg.e...@t-online.de>
* config/sh/sh.c (andcosts): Renamed to and_xor_ior_costs.
Added AND special case. Adapted comments.
(sh_rtx_costs): Added XOR and IOR case.
Index: gcc/config/sh/sh.c
===================================================================
--- gcc/config/sh/sh.c (revision 178760)
+++ gcc/config/sh/sh.c (working copy)
@@ -242,7 +242,7 @@
static int flow_dependent_p (rtx, rtx);
static void flow_dependent_p_1 (rtx, const_rtx, void *);
static int shiftcosts (rtx);
-static int andcosts (rtx);
+static int and_xor_ior_costs (rtx, int code);
static int addsubcosts (rtx);
static int multcosts (rtx);
static bool unspec_caller_rtx_p (rtx);
@@ -2830,14 +2830,14 @@
return shift_insns[value];
}
-/* Return the cost of an AND operation. */
+/* Return the cost of an AND/XOR/IOR operation. */
static inline int
-andcosts (rtx x)
+and_xor_ior_costs (rtx x, int code)
{
int i;
- /* Anding with a register is a single cycle and instruction. */
+ /* register x register is a single cycle instruction. */
if (!CONST_INT_P (XEXP (x, 1)))
return 1;
@@ -2853,17 +2853,17 @@
}
/* These constants are single cycle extu.[bw] instructions. */
- if (i == 0xff || i == 0xffff)
+ if ((i == 0xff || i == 0xffff) && code == AND)
return 1;
- /* Constants that can be used in an and immediate instruction in a single
+ /* Constants that can be used in an instruction with an immediate are a single
cycle, but this requires r0, so make it a little more expensive. */
if (CONST_OK_FOR_K08 (i))
return 2;
- /* Constants that can be loaded with a mov immediate and an and.
+ /* Constants that can be loaded with a mov immediate need one more cycle.
This case is probably unnecessary. */
if (CONST_OK_FOR_I08 (i))
return 2;
- /* Any other constants requires a 2 cycle pc-relative load plus an and.
+ /* Any other constant requires an additional 2 cycle pc-relative load.
This case is probably unnecessary. */
return 3;
}
@@ -3032,7 +3032,9 @@
return true;
case AND:
- *total = COSTS_N_INSNS (andcosts (x));
+ case XOR:
+ case IOR:
+ *total = COSTS_N_INSNS (and_xor_ior_costs (x, code));
return true;
case MULT:
