| dnl PowerPC 750 mpn_lshift -- mpn left shift. |
| |
| dnl Copyright 2002, 2003 Free Software Foundation, Inc. |
| |
| dnl This file is part of the GNU MP Library. |
| |
| dnl The GNU MP Library is free software; you can redistribute it and/or modify |
| dnl it under the terms of the GNU Lesser General Public License as published |
| dnl by the Free Software Foundation; either version 3 of the License, or (at |
| dnl your option) any later version. |
| |
| 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 Lesser General Public |
| dnl License for more details. |
| |
| 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 750: 3.0 |
| C 7400: 3.0 |
| |
| |
| C mp_limb_t mpn_lshift (mp_ptr dst, mp_srcptr src, mp_size_t size, |
| C unsigned shift); |
| C |
| C This code is the same per-limb speed as mpn/powerpc32/lshift.asm, but |
| C smaller and saving about 30 or so cycles of overhead. |
| |
| ASM_START() |
| PROLOGUE(mpn_lshift) |
| |
| C r3 dst |
| C r4 src |
| C r5 size |
| C r6 shift |
| |
| mtctr r5 C size |
| slwi r5, r5, 2 C 4*size |
| |
| subfic r7, r6, 32 C 32-shift |
| add r4, r4, r5 C &src[size] |
| |
| add r5, r3, r5 C &dst[size] |
| lwz r8, -4(r4) C src[size-1] |
| bdz L(one) |
| |
| lwzu r9, -8(r4) C src[size-2] |
| |
| srw r3, r8, r7 C return value |
| slw r8, r8, r6 C src[size-1] << shift |
| bdz L(two) |
| |
| |
| L(top): |
| C r3 return value |
| C r4 src, incrementing |
| C r5 dst, incrementing |
| C r6 lshift |
| C r7 32-shift |
| C r8 src[i+1] << shift |
| C r9 src[i] |
| C r10 |
| |
| lwzu r10, -4(r4) |
| srw r11, r9, r7 |
| |
| or r8, r8, r11 |
| stwu r8, -4(r5) |
| |
| slw r8, r9, r6 |
| bdz L(odd) |
| |
| C r8 src[i+1] << shift |
| C r9 |
| C r10 src[i] |
| |
| lwzu r9, -4(r4) |
| srw r11, r10, r7 |
| |
| or r8, r8, r11 |
| stwu r8, -4(r5) |
| |
| slw r8, r10, r6 |
| bdnz L(top) |
| |
| |
| L(two): |
| C r3 return value |
| C r4 |
| C r5 &dst[2] |
| C r6 shift |
| C r7 32-shift |
| C r8 src[1] << shift |
| C r9 src[0] |
| C r10 |
| |
| srw r11, r9, r7 |
| slw r12, r9, r6 C src[0] << shift |
| |
| or r8, r8, r11 |
| stw r12, -8(r5) C dst[0] |
| |
| stw r8, -4(r5) C dst[1] |
| blr |
| |
| |
| L(odd): |
| C r3 return value |
| C r4 |
| C r5 &dst[2] |
| C r6 shift |
| C r7 32-shift |
| C r8 src[1] << shift |
| C r9 |
| C r10 src[0] |
| |
| srw r11, r10, r7 |
| slw r12, r10, r6 |
| |
| or r8, r8, r11 |
| stw r12, -8(r5) C dst[0] |
| |
| stw r8, -4(r5) C dst[1] |
| blr |
| |
| |
| L(one): |
| C r5 &dst[1] |
| C r6 shift |
| C r7 32-shift |
| C r8 src[0] |
| |
| srw r3, r8, r7 C return value |
| slw r8, r8, r6 C src[size-1] << shift |
| |
| stw r8, -4(r5) C dst[0] |
| blr |
| |
| EPILOGUE(mpn_lshift) |