Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / c6x / lib / divremu.S

diff --git a/kernel/arch/c6x/lib/divremu.S b/kernel/arch/c6x/lib/divremu.S
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+++ b/kernel/arch/c6x/lib/divremu.S
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+;;  Copyright 2011  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>
+
+       .text
+ENTRY(__c6xabi_divremu)
+       ;; We use a series of up to 31 subc instructions.  First, we find
+       ;; out how many leading zero bits there are in the divisor.  This
+       ;; gives us both a shift count for aligning (shifting) the divisor
+       ;; to the, and the number of times we have to execute subc.
+
+       ;; At the end, we have both the remainder and most of the quotient
+       ;; in A4.  The top bit of the quotient is computed first and is
+       ;; placed in A2.
+
+       ;; Return immediately if the dividend is zero.  Setting B4 to 1
+       ;; is a trick to allow us to leave the following insns in the jump
+       ;; delay slot without affecting the result.
+       mv      .s2x    A4, B1
+
+  [b1] lmbd    .l2     1, B4, B1
+||[!b1] b      .s2     B3      ; RETURN A
+||[!b1] mvk    .d2     1, B4
+
+||[!b1] zero   .s1     A5
+       mv      .l1x    B1, A6
+||     shl     .s2     B4, B1, B4
+
+       ;; The loop performs a maximum of 28 steps, so we do the
+       ;; first 3 here.
+       cmpltu  .l1x    A4, B4, A2
+  [!A2]        sub     .l1x    A4, B4, A4
+||     shru    .s2     B4, 1, B4
+||     xor     .s1     1, A2, A2
+
+       shl     .s1     A2, 31, A2
+|| [b1]        subc    .l1x    A4,B4,A4
+|| [b1]        add     .s2     -1, B1, B1
+   [b1]        subc    .l1x    A4,B4,A4
+|| [b1]        add     .s2     -1, B1, B1
+
+       ;; RETURN A may happen here (note: must happen before the next branch)
+__divremu0:
+       cmpgt   .l2     B1, 7, B0
+|| [b1]        subc    .l1x    A4,B4,A4
+|| [b1]        add     .s2     -1, B1, B1
+   [b1]        subc    .l1x    A4,B4,A4
+|| [b1]        add     .s2     -1, B1, B1
+|| [b0] b      .s1     __divremu0
+   [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
+||     mvk     .s1     32, A1
+       sub     .l1     A1, A6, A6
+||     extu    .s1     A4, A6, A5
+       shl     .s1     A4, A6, A4
+       shru    .s1     A4, 1, A4
+||     sub     .l1     A6, 1, A6
+       or      .l1     A2, A4, A4
+       shru    .s1     A4, A6, A4
+       nop
+ENDPROC(__c6xabi_divremu)