42 lines
1.2 KiB
ArmAsm
42 lines
1.2 KiB
ArmAsm
;; SPDX-License-Identifier: GPL-2.0-or-later
|
|
;; Copyright 2010 Free Software Foundation, Inc.
|
|
;; Contributed by Bernd Schmidt <bernds@codesourcery.com>.
|
|
;;
|
|
|
|
#include <linux/linkage.h>
|
|
|
|
;; ABI considerations for the divide functions
|
|
;; The following registers are call-used:
|
|
;; __c6xabi_divi A0,A1,A2,A4,A6,B0,B1,B2,B4,B5
|
|
;; __c6xabi_divu A0,A1,A2,A4,A6,B0,B1,B2,B4
|
|
;; __c6xabi_remi A1,A2,A4,A5,A6,B0,B1,B2,B4
|
|
;; __c6xabi_remu A1,A4,A5,A7,B0,B1,B2,B4
|
|
;;
|
|
;; In our implementation, divu and remu are leaf functions,
|
|
;; while both divi and remi call into divu.
|
|
;; A0 is not clobbered by any of the functions.
|
|
;; divu does not clobber B2 either, which is taken advantage of
|
|
;; in remi.
|
|
;; divi uses B5 to hold the original return address during
|
|
;; the call to divu.
|
|
;; remi uses B2 and A5 to hold the input values during the
|
|
;; call to divu. It stores B3 in on the stack.
|
|
|
|
.text
|
|
ENTRY(__c6xabi_divi)
|
|
call .s2 __c6xabi_divu
|
|
|| mv .d2 B3, B5
|
|
|| cmpgt .l1 0, A4, A1
|
|
|| cmpgt .l2 0, B4, B1
|
|
|
|
[A1] neg .l1 A4, A4
|
|
|| [B1] neg .l2 B4, B4
|
|
|| xor .s1x A1, B1, A1
|
|
[A1] addkpc .s2 _divu_ret, B3, 4
|
|
_divu_ret:
|
|
neg .l1 A4, A4
|
|
|| mv .l2 B3,B5
|
|
|| ret .s2 B5
|
|
nop 5
|
|
ENDPROC(__c6xabi_divi)
|