Reorganisation of the source tree

[ghc-hetmet.git] / rts / gmp / mpn / m68k / sub_n.S

diff --git a/rts/gmp/mpn/m68k/sub_n.S b/rts/gmp/mpn/m68k/sub_n.S
new file mode 100644 (file)
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+++ b/rts/gmp/mpn/m68k/sub_n.S
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+/* mc68020 __gmpn_sub_n -- Subtract two limb vectors of the same length > 0 and
+   store difference in a third limb vector.
+
+Copyright (C) 1992, 1994, 1996, 1999, 2000 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or (at your
+option) any later version.
+
+The GNU MP Library 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 Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+MA 02111-1307, USA. */
+
+/*
+  INPUT PARAMETERS
+  res_ptr      (sp + 4)
+  s1_ptr       (sp + 8)
+  s2_ptr       (sp + 16)
+  size         (sp + 12)
+*/
+
+#include "asm-syntax.h"
+
+       TEXT
+       ALIGN
+       GLOBL   C_SYMBOL_NAME(__gmpn_sub_n)
+
+C_SYMBOL_NAME(__gmpn_sub_n:)
+PROLOG(__gmpn_sub_n)
+/* Save used registers on the stack.  */
+       movel   R(d2),MEM_PREDEC(sp)
+       movel   R(a2),MEM_PREDEC(sp)
+
+/* Copy the arguments to registers.  Better use movem?  */
+       movel   MEM_DISP(sp,12),R(a2)
+       movel   MEM_DISP(sp,16),R(a0)
+       movel   MEM_DISP(sp,20),R(a1)
+       movel   MEM_DISP(sp,24),R(d2)
+
+       eorw    #1,R(d2)
+       lsrl    #1,R(d2)
+       bcc     L(L1)
+       subql   #1,R(d2)        /* clears cy as side effect */
+
+L(Loop:)
+       movel   MEM_POSTINC(a0),R(d0)
+       movel   MEM_POSTINC(a1),R(d1)
+       subxl   R(d1),R(d0)
+       movel   R(d0),MEM_POSTINC(a2)
+L(L1:) movel   MEM_POSTINC(a0),R(d0)
+       movel   MEM_POSTINC(a1),R(d1)
+       subxl   R(d1),R(d0)
+       movel   R(d0),MEM_POSTINC(a2)
+
+       dbf     R(d2),L(Loop)           /* loop until 16 lsb of %4 == -1 */
+       subxl   R(d0),R(d0)     /* d0 <= -cy; save cy as 0 or -1 in d0 */
+       subl    #0x10000,R(d2)
+       bcs     L(L2)
+       addl    R(d0),R(d0)     /* restore cy */
+       bra     L(Loop)
+
+L(L2:)
+       negl    R(d0)
+
+/* Restore used registers from stack frame.  */
+       movel   MEM_POSTINC(sp),R(a2)
+       movel   MEM_POSTINC(sp),R(d2)
+
+       rts
+EPILOG(__gmpn_sub_n)