diff options
Diffstat (limited to 'sysdeps/arm/add_n.S')
| -rw-r--r-- | sysdeps/arm/add_n.S | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/sysdeps/arm/add_n.S b/sysdeps/arm/add_n.S new file mode 100644 index 0000000000..4cc1ac287f --- /dev/null +++ b/sysdeps/arm/add_n.S @@ -0,0 +1,99 @@ +/* mpn_add_n -- add (or subtract) bignums. + Copyright (C) 2013-2014 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, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include <arm-features.h> + + .syntax unified + .text + +#ifdef USE_AS_SUB_N +# define INITC cmp r0, r0 +# define OPC sbcs +# define RETC sbc r0, r0, r0; neg r0, r0 +# define FUNC __mpn_sub_n +#else +# define INITC cmn r0, #0 +# define OPC adcs +# define RETC mov r0, #0; adc r0, r0, r0 +# define FUNC __mpn_add_n +#endif + +/* mp_limb_t mpn_add_n(res_ptr, src1_ptr, src2_ptr, size) */ + +ENTRY (FUNC) + push { r4, r5, r6, r7, r8, r10, lr } + cfi_adjust_cfa_offset (28) + cfi_rel_offset (r4, 0) + cfi_rel_offset (r5, 4) + cfi_rel_offset (r6, 8) + cfi_rel_offset (r7, 12) + cfi_rel_offset (r8, 16) + cfi_rel_offset (r10, 20) + cfi_rel_offset (lr, 24) + + INITC /* initialize carry flag */ + tst r3, #1 /* count & 1 == 1? */ + add lr, r1, r3, lsl #2 /* compute end src1 */ + beq 1f + + sfi_breg r1, \ + ldr r4, [\B], #4 /* do one to make count even */ + sfi_breg r2, \ + ldr r5, [\B], #4 + OPC r4, r4, r5 + teq r1, lr /* end of count? (preserve carry) */ + sfi_breg r0, \ + str r4, [\B], #4 + beq 9f +1: + tst r3, #2 /* count & 2 == 2? */ + beq 2f + sfi_breg r1, \ + ldm \B!, { r4, r5 } /* do two to make count 0 mod 4 */ + sfi_breg r2, \ + ldm \B!, { r6, r7 } + OPC r4, r4, r6 + OPC r5, r5, r7 + teq r1, lr /* end of count? */ + sfi_breg r0, \ + stm \B!, { r4, r5 } + beq 9f +2: + sfi_breg r1, \ + ldm \B!, { r3, r5, r7, r10 } /* do four each loop */ + sfi_breg r2, \ + ldm \B!, { r4, r6, r8, ip } + OPC r3, r3, r4 + OPC r5, r5, r6 + OPC r7, r7, r8 + OPC r10, r10, ip + teq r1, lr + sfi_breg r0, \ + stm \B!, { r3, r5, r7, r10 } + bne 2b + +9: + RETC /* copy carry out */ +#ifndef ARM_ALWAYS_BX + pop { r4, r5, r6, r7, r8, r10, pc } +#else + pop { r4, r5, r6, r7, r8, r10, lr } + bx lr +#endif +END (FUNC) |