Moin guys,
this little patch improves 16*8 multiplication to some degree.
The FSF did'n yet send the assignment papers, but maybe the stuff is
still useful all the same.
cheers
Georg-Johann
Index: avr.md
===================================================================
--- avr.md (Revision 147721)
+++ avr.md (Arbeitskopie)
@@ -980,18 +980,31 @@
(define_expand "mulhi3"
[(set (match_operand:HI 0 "register_operand" "")
(mult:HI (match_operand:HI 1 "register_operand" "")
- (match_operand:HI 2 "register_operand" "")))]
+ (match_operand:HI 2 "nonmemory_operand" "")))]
""
"
{
if (!AVR_HAVE_MUL)
{
+ if (!register_operand (operands[2], HImode))
+ operands[2] = copy_to_mode_reg (HImode, operands[2]);
emit_insn (gen_mulhi3_call (operands[0], operands[1], operands[2]));
DONE;
}
+ else if (immediate_operand (operands[2], HImode))
+ {
+ enum machine_mode mode = (satisfies_constraint_M (operands[2])) ? QImode : HImode;
+
+ operands[2] = force_reg (mode, operands[2]);
+ if (HImode == mode)
+ emit_insn (gen_mulhi3_enh (operands[0], operands[1], operands[2]));
+ else
+ emit_insn (gen_umulhi3_enh_zerox (operands[0], operands[2], operands[1]));
+ DONE;
+ }
}")
-(define_insn "*mulhi3_enh"
+(define_insn "mulhi3_enh"
[(set (match_operand:HI 0 "register_operand" "=&r")
(mult:HI (match_operand:HI 1 "register_operand" "r")
(match_operand:HI 2 "register_operand" "r")))]
@@ -1006,6 +1019,19 @@
[(set_attr "length" "7")
(set_attr "cc" "clobber")])
+(define_insn "umulhi3_enh_zerox"
+ [(set (match_operand:HI 0 "register_operand" "=&r")
+ (mult:HI (zero_extend:HI (match_operand:QI 1 "register_operand" "r"))
+ (match_operand:HI 2 "register_operand" "r")))]
+ "AVR_HAVE_MUL"
+ "mul %A2,%1
+ movw %0,r0
+ mul %B2,%1
+ add %B0,r0
+ clr r1"
+ [(set_attr "length" "5")
+ (set_attr "cc" "clobber")])
+
(define_expand "mulhi3_call"
[(set (reg:HI 24) (match_operand:HI 1 "register_operand" ""))
(set (reg:HI 22) (match_operand:HI 2 "register_operand" ""))
Index: avr.c
===================================================================
--- avr.c (Revision 147721)
+++ avr.c (Arbeitskopie)
@@ -45,6 +45,7 @@
#include "target-def.h"
#include "params.h"
#include "df.h"
+#include "tm-constrs.h"
/* Maximal allowed offset for an address in the LD command */
#define MAX_LD_OFFSET(MODE) (64 - (signed)GET_MODE_SIZE (MODE))
@@ -5055,6 +5056,14 @@ avr_operand_rtx_cost (rtx x, enum machin
case CONST_DOUBLE:
return COSTS_N_INSNS (GET_MODE_SIZE (mode));
+ case ZERO_EXTEND:
+ if (HImode == mode
+ && MULT == outer)
+ {
+ return 0;
+ }
+ break;
+
default:
break;
}
@@ -5203,7 +5212,7 @@ avr_rtx_costs (rtx x, int code, int oute
{
case QImode:
if (AVR_HAVE_MUL)
- *total = COSTS_N_INSNS (!speed ? 3 : 4);
+ *total = COSTS_N_INSNS (!speed ? 3 : 4);
else if (!speed)
*total = COSTS_N_INSNS (AVR_HAVE_JMP_CALL ? 2 : 1);
else
@@ -5212,7 +5221,18 @@ avr_rtx_costs (rtx x, int code, int oute
case HImode:
if (AVR_HAVE_MUL)
- *total = COSTS_N_INSNS (!speed ? 7 : 10);
+ {
+ if (ZERO_EXTEND == GET_CODE (XEXP (x, 0))
+ && ZERO_EXTEND == GET_CODE (XEXP (x, 1)))
+ *total = COSTS_N_INSNS (!speed ? 3 : 4);
+ else if (satisfies_constraint_M (XEXP (x, 0))
+ || satisfies_constraint_M (XEXP (x, 1))
+ || ZERO_EXTEND == GET_CODE (XEXP (x, 0))
+ || ZERO_EXTEND == GET_CODE (XEXP (x, 1)))
+ *total = COSTS_N_INSNS (!speed ? 5 : 6);
+ else
+ *total = COSTS_N_INSNS (!speed ? 7 : 10);
+ }
else if (!speed)
*total = COSTS_N_INSNS (AVR_HAVE_JMP_CALL ? 2 : 1);
else
@@ -5313,8 +5333,10 @@ avr_rtx_costs (rtx x, int code, int oute
case 9:
*total = COSTS_N_INSNS (3);
break;
- case 2:
case 3:
+ *total = COSTS_N_INSNS (!speed ? 4 : 6);
+ break;
+ case 2:
case 10:
case 15:
*total = COSTS_N_INSNS (4);
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