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authorLinus Torvalds <torvalds@linux-foundation.org>2012-01-10 17:39:40 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-10 17:39:40 -0800
commit06792c4dde2ad143928cc95c1ba218c6269c494b (patch)
tree92bdd4631612c9e3d8e5f6f06839f75c5473300a /arch/c6x/lib/divi.S
parent4690dfa8cd66c37fbe99bb8cd5baa86102110776 (diff)
parent166c0eaedfc3157dc1394c27e827add19f05fb27 (diff)
Merge tag 'for-linux-3.3-merge-window' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming
* tag 'for-linux-3.3-merge-window' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming: (29 commits) C6X: replace tick_nohz_stop/restart_sched_tick calls C6X: add register_cpu call C6X: deal with memblock API changes C6X: fix timer64 initialization C6X: fix layout of EMIFA registers C6X: MAINTAINERS C6X: DSCR - Device State Configuration Registers C6X: EMIF - External Memory Interface C6X: general SoC support C6X: library code C6X: headers C6X: ptrace support C6X: loadable module support C6X: cache control C6X: clocks C6X: build infrastructure C6X: syscalls C6X: interrupt handling C6X: time management C6X: signal management ...
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+;; Copyright 2010 Free Software Foundation, Inc.
+;; Contributed by Bernd Schmidt <bernds@codesourcery.com>.
+;;
+;; 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.
+
+#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)