diff options
Diffstat (limited to 'sysdeps/powerpc/lshift.S')
-rw-r--r-- | sysdeps/powerpc/lshift.S | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/sysdeps/powerpc/lshift.S b/sysdeps/powerpc/lshift.S new file mode 100644 index 0000000000..b1487a1c17 --- /dev/null +++ b/sysdeps/powerpc/lshift.S @@ -0,0 +1,123 @@ +/* Shift a limb left, low level routine. + Copyright (C) 1996, 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C 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. */ + +#include <sysdep.h> + +/* mp_limb_t mpn_lshift (mp_ptr wp, mp_srcptr up, mp_size_t usize, + unsigned int cnt) */ + +EALIGN(__mpn_lshift,3,0) + mtctr %r5 # copy size into CTR + cmplwi %cr0,%r5,16 # is size < 16 + slwi %r0,%r5,2 + add %r7,%r3,%r0 # make r7 point at end of res + add %r4,%r4,%r0 # make r4 point at end of s1 + lwzu %r11,-4(%r4) # load first s1 limb + subfic %r8,%r6,32 + srw %r3,%r11,%r8 # compute function return value + bge %cr0,L(big) # branch if size >= 16 + + bdz L(end1) + +0: lwzu %r10,-4(%r4) + slw %r9,%r11,%r6 + srw %r12,%r10,%r8 + or %r9,%r9,%r12 + stwu %r9,-4(%r7) + bdz L(end2) + lwzu %r11,-4(%r4) + slw %r9,%r10,%r6 + srw %r12,%r11,%r8 + or %r9,%r9,%r12 + stwu %r9,-4(%r7) + bdnz 0b + +L(end1):slw %r0,%r11,%r6 + stw %r0,-4(%r7) + blr + + +/* Guaranteed not to succeed. */ +L(boom): tweq %r0,%r0 + +/* We imitate a case statement, by using (yuk!) fixed-length code chunks, + of size 4*12 bytes. We have to do this (or something) to make this PIC. */ +L(big): mflr %r9 + bltl- %cr0,L(boom) # Never taken, only used to set LR. + slwi %r10,%r6,4 + mflr %r12 + add %r10,%r12,%r10 + slwi %r8,%r6,5 + add %r10,%r8,%r10 + mtctr %r10 + addi %r5,%r5,-1 + mtlr %r9 + bctr + +L(end2):slw %r0,%r10,%r6 + stw %r0,-4(%r7) + blr + +#define DO_LSHIFT(n) \ + mtctr %r5; \ +0: lwzu %r10,-4(%r4); \ + slwi %r9,%r11,n; \ + inslwi %r9,%r10,n,32-n; \ + stwu %r9,-4(%r7); \ + bdz- L(end2); \ + lwzu %r11,-4(%r4); \ + slwi %r9,%r10,n; \ + inslwi %r9,%r11,n,32-n; \ + stwu %r9,-4(%r7); \ + bdnz 0b; \ + b L(end1) + + DO_LSHIFT(1) + DO_LSHIFT(2) + DO_LSHIFT(3) + DO_LSHIFT(4) + DO_LSHIFT(5) + DO_LSHIFT(6) + DO_LSHIFT(7) + DO_LSHIFT(8) + DO_LSHIFT(9) + DO_LSHIFT(10) + DO_LSHIFT(11) + DO_LSHIFT(12) + DO_LSHIFT(13) + DO_LSHIFT(14) + DO_LSHIFT(15) + DO_LSHIFT(16) + DO_LSHIFT(17) + DO_LSHIFT(18) + DO_LSHIFT(19) + DO_LSHIFT(20) + DO_LSHIFT(21) + DO_LSHIFT(22) + DO_LSHIFT(23) + DO_LSHIFT(24) + DO_LSHIFT(25) + DO_LSHIFT(26) + DO_LSHIFT(27) + DO_LSHIFT(28) + DO_LSHIFT(29) + DO_LSHIFT(30) + DO_LSHIFT(31) + +END(__mpn_lshift) |