--- /dev/null
+dnl mc68020 mpn_lshift -- mpn left shift.
+
+dnl Copyright 1996, 1999, 2000, 2001, 2002, 2003 Free Software Foundation,
+dnl Inc.
+dnl
+dnl This file is part of the GNU MP Library.
+dnl
+dnl The GNU MP Library is free software; you can redistribute it and/or
+dnl modify it under the terms of the GNU Lesser General Public License as
+dnl published by the Free Software Foundation; either version 3 of the
+dnl License, or (at your option) any later version.
+dnl
+dnl The GNU MP Library is distributed in the hope that it will be useful,
+dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
+dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+dnl Lesser General Public License for more details.
+dnl
+dnl You should have received a copy of the GNU Lesser General Public License
+dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/.
+
+include(`../config.m4')
+
+
+C cycles/limb
+C shift==1 shift>1
+C 68040: 5 12
+
+
+C mp_limb_t mpn_lshift (mp_ptr res_ptr, mp_srcptr s_ptr, mp_size_t s_size,
+C unsigned cnt);
+C
+C The "cnt" parameter is either 16 bits or 32 bits depending on
+C SIZEOF_UNSIGNED (see ABI notes in mpn/m68k/README). The value is of
+C course only 1 to 31. When loaded as 16 bits there's garbage in the upper
+C half, hence the use of cmpw. The shift instructions take the their count
+C modulo 64, so the upper part doesn't matter to them either.
+C
+
+C INPUT PARAMETERS
+C res_ptr (sp + 4)
+C s_ptr (sp + 8)
+C s_size (sp + 12)
+C cnt (sp + 16)
+
+define(res_ptr, `a1')
+define(s_ptr, `a0')
+define(s_size, `d6')
+define(cnt, `d4')
+
+ifdef(`SIZEOF_UNSIGNED',,
+`m4_error(`SIZEOF_UNSIGNED not defined, should be in config.m4
+')')
+
+PROLOGUE(mpn_lshift)
+C Save used registers on the stack.
+ moveml d2-d6/a2, M(-,sp)
+
+C Copy the arguments to registers.
+ movel M(sp,28), res_ptr
+ movel M(sp,32), s_ptr
+ movel M(sp,36), s_size
+ifelse(SIZEOF_UNSIGNED,2,
+` movew M(sp,40), cnt',
+` movel M(sp,40), cnt')
+
+ moveql #1, d5
+ cmpw d5, cnt
+ bne L(Lnormal)
+ cmpl s_ptr, res_ptr
+ bls L(Lspecial) C jump if s_ptr >= res_ptr
+
+ifelse(scale_available_p,1,`
+ lea M(s_ptr,s_size,l,4), a2
+',`
+ movel s_size, d0
+ asll #2, d0
+ lea M(s_ptr,d0,l), a2
+')
+ cmpl res_ptr, a2
+ bls L(Lspecial) C jump if res_ptr >= s_ptr + s_size
+
+L(Lnormal):
+ moveql #32, d5
+ subl cnt, d5
+
+ifelse(scale_available_p,1,`
+ lea M(s_ptr,s_size,l,4), s_ptr
+ lea M(res_ptr,s_size,l,4), res_ptr
+',`
+ movel s_size, d0
+ asll #2, d0
+ addl d0, s_ptr
+ addl d0, res_ptr
+')
+ movel M(-,s_ptr), d2
+ movel d2, d0
+ lsrl d5, d0 C compute carry limb
+
+ lsll cnt, d2
+ movel d2, d1
+ subql #1, s_size
+ beq L(Lend)
+ lsrl #1, s_size
+ bcs L(L1)
+ subql #1, s_size
+
+L(Loop:)
+ movel M(-,s_ptr), d2
+ movel d2, d3
+ lsrl d5, d3
+ orl d3, d1
+ movel d1, M(-,res_ptr)
+ lsll cnt, d2
+L(L1:)
+ movel M(-,s_ptr), d1
+ movel d1, d3
+ lsrl d5, d3
+ orl d3, d2
+ movel d2, M(-,res_ptr)
+ lsll cnt, d1
+
+ dbf s_size, L(Loop)
+ subl #0x10000, s_size
+ bcc L(Loop)
+
+L(Lend:)
+ movel d1, M(-,res_ptr) C store least significant limb
+
+C Restore used registers from stack frame.
+ moveml M(sp,+), d2-d6/a2
+ rts
+
+C We loop from least significant end of the arrays, which is only
+C permissable if the source and destination don't overlap, since the
+C function is documented to work for overlapping source and destination.
+
+L(Lspecial):
+ clrl d0 C initialize carry
+ eorw #1, s_size
+ lsrl #1, s_size
+ bcc L(LL1)
+ subql #1, s_size
+
+L(LLoop):
+ movel M(s_ptr,+), d2
+ addxl d2, d2
+ movel d2, M(res_ptr,+)
+L(LL1):
+ movel M(s_ptr,+), d2
+ addxl d2, d2
+ movel d2, M(res_ptr,+)
+
+ dbf s_size, L(LLoop)
+ addxl d0, d0 C save cy in lsb
+ subl #0x10000, s_size
+ bcs L(LLend)
+ lsrl #1, d0 C restore cy
+ bra L(LLoop)
+
+L(LLend):
+C Restore used registers from stack frame.
+ moveml M(sp,+), d2-d6/a2
+ rts
+
+EPILOGUE(mpn_lshift)
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