Hello.
Now cost of moving 1, 2, 4-bytes data from register to register is 2 and
cost of moving to/from SP register is increased. But moving 1 byte of data
between registers request one MOV instruction ,moving 2 bytes two MOV
instruction or one MOVW instruction on devices which have it and etc. I have
changed REGISTER_MOVE_COST macro to consider it.
Also cost of register to memory moves is increased by 2 that the GCC prefer
register to register moves rather register to memory moves.
I have received ~0.6% code size decrease on test projects.
I will be grateful for testing and feedback on this patch.
Index: gcc/config/avr/avr-protos.h
===================================================================
--- gcc/config/avr/avr-protos.h (revision 163854)
+++ gcc/config/avr/avr-protos.h (working copy)
@@ -38,6 +38,8 @@
extern rtx avr_return_addr_rtx (int count, const_rtx tem);
#ifdef TREE_CODE
+extern int avr_register_move_cost (enum machine_mode, int, int);
+extern int avr_memory_move_cost (enum machine_mode, int, bool);
extern void asm_output_external (FILE *file, tree decl, char *name);
extern int avr_progmem_p (tree decl, tree attributes);
Index: gcc/config/avr/avr.c
===================================================================
--- gcc/config/avr/avr.c (revision 163854)
+++ gcc/config/avr/avr.c (working copy)
@@ -5039,7 +5039,60 @@
reg_alloc_order[i] = order[i];
}
+/* Implements REGISTER_MOVE_COST. */
+int
+avr_register_move_cost (enum machine_mode mode,
+ int from, int to)
+{
+ if (from == STACK_REG)
+ return 6;
+ else if (to == STACK_REG)
+ return 12;
+ else
+ {
+ if (mode == QImode)
+ return 2;
+ if (mode == HImode)
+ {
+ if (AVR_HAVE_MOVW)
+ return 2;
+ else
+ return 4;
+ }
+ if (mode == SImode || mode ==SFmode)
+ {
+ if (AVR_HAVE_MOVW)
+ return 4;
+ else
+ return 8;
+ }
+ else
+ {
+ if (AVR_HAVE_MOVW)
+ return 8;
+ else
+ return 16;
+ }
+ }
+}
+
+/* Implements MEMORY_MOVE_COST. */
+
+int
+avr_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
+ int rclass ATTRIBUTE_UNUSED,
+ bool in ATTRIBUTE_UNUSED)
+{
+ if (mode == QImode)
+ return 4;
+ if (mode == HImode)
+ return 6;
+ if (mode == SImode || mode ==SFmode)
+ return 10;
+ else
+ return 18;
+}
/* Mutually recursive subroutine of avr_rtx_cost for calculating the
cost of an RTX operand given its context. X is the rtx of the
operand, MODE is its mode, and OUTER is the rtx_code of this
Index: gcc/config/avr/avr.h
===================================================================
--- gcc/config/avr/avr.h (revision 163854)
+++ gcc/config/avr/avr.h (working copy)
@@ -462,15 +462,11 @@
#define LEGITIMATE_CONSTANT_P(X) 1
-#define REGISTER_MOVE_COST(MODE, FROM, TO) ((FROM) == STACK_REG ? 6 \
- : (TO) == STACK_REG ? 12 \
- : 2)
+#define REGISTER_MOVE_COST(MODE, FROM, TO) \
+ avr_register_move_cost ((MODE), (FROM), (TO))
+#define MEMORY_MOVE_COST(MODE, CLASS, IN) \
+ avr_memory_move_cost ((MODE), (CLASS), (IN))
-#define MEMORY_MOVE_COST(MODE,CLASS,IN) ((MODE)==QImode ? 2 : \
- (MODE)==HImode ? 4 : \
- (MODE)==SImode ? 8 : \
- (MODE)==SFmode ? 8 : 16)
-
#define BRANCH_COST(speed_p, predictable_p) 0
#define SLOW_BYTE_ACCESS 0
Anatoly.
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