Files
Linux_Drivers/linux_5.10/arch/h8300/lib/mulsi3.S
sam.xiang 5c7dd7acc3 [linux] create linux_5.10.4 from T-head official:
repo: https://github.com/T-head-Semi/linux
	commit: b1313fe517ca3703119dcc99ef3bbf75ab42bcfb

Change-Id: I6cbb35294024ea3a66140e311f4bb705fd7fd626
2023-03-10 20:32:41 +08:00

40 lines
714 B
ArmAsm

; SPDX-License-Identifier: GPL-2.0
;
; mulsi3 for H8/300H - based on Renesas SH implementation
;
; by Toshiyasu Morita
;
; Old code:
;
; 16b * 16b = 372 states (worst case)
; 32b * 32b = 724 states (worst case)
;
; New code:
;
; 16b * 16b = 48 states
; 16b * 32b = 72 states
; 32b * 32b = 92 states
;
.global __mulsi3
__mulsi3:
mov.w r1,r2 ; ( 2 states) b * d
mulxu r0,er2 ; (22 states)
mov.w e0,r3 ; ( 2 states) a * d
beq L_skip1 ; ( 4 states)
mulxu r1,er3 ; (22 states)
add.w r3,e2 ; ( 2 states)
L_skip1:
mov.w e1,r3 ; ( 2 states) c * b
beq L_skip2 ; ( 4 states)
mulxu r0,er3 ; (22 states)
add.w r3,e2 ; ( 2 states)
L_skip2:
mov.l er2,er0 ; ( 2 states)
rts ; (10 states)
.end