| dnl mc68020 mpn_lshift -- mpn left shift. |
| |
| dnl Copyright 1996, 1999-2003 Free Software Foundation, Inc. |
| |
| 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 modify |
| dnl it under the terms of either: |
| dnl |
| dnl * the GNU Lesser General Public License as published by the Free |
| dnl Software Foundation; either version 3 of the License, or (at your |
| dnl option) any later version. |
| dnl |
| dnl or |
| dnl |
| dnl * the GNU General Public License as published by the Free Software |
| dnl Foundation; either version 2 of the License, or (at your option) any |
| dnl later version. |
| dnl |
| dnl or both in parallel, as here. |
| dnl |
| dnl The GNU MP Library is distributed in the hope that it will be useful, but |
| dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| dnl for more details. |
| dnl |
| dnl You should have received copies of the GNU General Public License and the |
| dnl GNU Lesser General Public License along with the GNU MP Library. If not, |
| dnl see https://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) |