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Diffstat (limited to 'sysdeps/powerpc/powerpc32/lshift.S')
| -rw-r--r-- | sysdeps/powerpc/powerpc32/lshift.S | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc32/lshift.S b/sysdeps/powerpc/powerpc32/lshift.S new file mode 100644 index 0000000000..9f5870d828 --- /dev/null +++ b/sysdeps/powerpc/powerpc32/lshift.S @@ -0,0 +1,131 @@ +/* Shift a limb left, low level routine. + Copyright (C) 1996, 1997, 1999, 2000 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 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 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <sysdep.h> +#include <bp-sym.h> +#include <bp-asm.h> + +/* mp_limb_t mpn_lshift (mp_ptr wp, mp_srcptr up, mp_size_t usize, + unsigned int cnt) */ + +EALIGN (BP_SYM (__mpn_lshift), 3, 0) + +#if __BOUNDED_POINTERS__ + slwi r10,r5,2 /* convert limbs to bytes */ + CHECK_BOUNDS_BOTH_WIDE (r3, r8, r9, r10) + CHECK_BOUNDS_BOTH_WIDE (r4, r8, r9, r10) +#endif + 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) + +L(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 L(0) + +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; \ +L(n): 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 L(n); \ + 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 (BP_SYM (__mpn_lshift)) |