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linux-next/arch/c6x/lib/remu.S
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00

71 lines
1.9 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_remu)
;; The ABI seems designed to prevent these functions calling each other,
;; so we duplicate most of the divsi3 code here.
mv .s2x A4, B1
lmbd .l2 1, B4, B1
|| [!B1] b .s2 B3 ; RETURN A
|| [!B1] mvk .d2 1, B4
mv .l1x B1, A7
|| shl .s2 B4, B1, B4
cmpltu .l1x A4, B4, A1
[!A1] sub .l1x A4, B4, A4
shru .s2 B4, 1, B4
_remu_loop:
cmpgt .l2 B1, 7, B0
|| [B1] subc .l1x A4,B4,A4
|| [B1] add .s2 -1, B1, B1
;; RETURN A may happen here (note: must happen before the next branch)
[B1] subc .l1x A4,B4,A4
|| [B1] add .s2 -1, B1, B1
|| [B0] b .s1 _remu_loop
[B1] subc .l1x A4,B4,A4
|| [B1] add .s2 -1, B1, B1
[B1] subc .l1x A4,B4,A4
|| [B1] add .s2 -1, B1, B1
[B1] subc .l1x A4,B4,A4
|| [B1] add .s2 -1, B1, B1
[B1] subc .l1x A4,B4,A4
|| [B1] add .s2 -1, B1, B1
[B1] subc .l1x A4,B4,A4
|| [B1] add .s2 -1, B1, B1
;; loop backwards branch happens here
ret .s2 B3
[B1] subc .l1x A4,B4,A4
|| [B1] add .s2 -1, B1, B1
[B1] subc .l1x A4,B4,A4
extu .s1 A4, A7, A4
nop 2
ENDPROC(__c6xabi_remu)