diff options
Diffstat (limited to 'sysdeps/csky/abiv2/memcmp.S')
| -rw-r--r-- | sysdeps/csky/abiv2/memcmp.S | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/sysdeps/csky/abiv2/memcmp.S b/sysdeps/csky/abiv2/memcmp.S new file mode 100644 index 0000000000..d23f7e7b8f --- /dev/null +++ b/sysdeps/csky/abiv2/memcmp.S @@ -0,0 +1,142 @@ +/* The assembly function for memory compare. C-SKY ABIV2 version. + Copyright (C) 2018 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> + +ENTRY (memcmp) + /* Test if len less than 4 bytes. */ + mov r3, r0 + movi r0, 0 + mov r12, r4 + cmplti r2, 4 + jbt .L_compare_by_byte + + andi r13, r0, 3 + movi r19, 4 + /* Test if s1 is not 4 bytes aligned. */ + bnez r13, .L_s1_not_aligned + + LABLE_ALIGN +.L_s1_aligned: + /* If dest is aligned, then copy. */ + zext r18, r2, 31, 4 + /* Test if len less than 16 bytes. */ + bez r18, .L_compare_by_word + +.L_compare_by_4word: + /* If aligned, load word each time. */ + ldw r20, (r3, 0) + ldw r21, (r1, 0) + /* If s1[i] != s2[i], goto .L_byte_check. */ + cmpne r20, r21 + bt .L_byte_check + + ldw r20, (r3, 4) + ldw r21, (r1, 4) + cmpne r20, r21 + bt .L_byte_check + + ldw r20, (r3, 8) + ldw r21, (r1, 8) + cmpne r20, r21 + bt .L_byte_check + + ldw r20, (r3, 12) + ldw r21, (r1, 12) + cmpne r20, r21 + bt .L_byte_check + + PRE_BNEZAD (r18) + addi a3, 16 + addi a1, 16 + + BNEZAD (r18, .L_compare_by_4word) + +.L_compare_by_word: + zext r18, r2, 3, 2 + bez r18, .L_compare_by_byte +.L_compare_by_word_loop: + ldw r20, (r3, 0) + ldw r21, (r1, 0) + addi r3, 4 + PRE_BNEZAD (r18) + cmpne r20, r21 + addi r1, 4 + bt .L_byte_check + BNEZAD (r18, .L_compare_by_word_loop) + +.L_compare_by_byte: + zext r18, r2, 1, 0 + bez r18, .L_return +.L_compare_by_byte_loop: + ldb r0, (r3, 0) + ldb r4, (r1, 0) + addi r3, 1 + subu r0, r4 + PRE_BNEZAD (r18) + addi r1, 1 + bnez r0, .L_return + BNEZAD (r18, .L_compare_by_byte_loop) + +.L_return: + mov r4, r12 + rts + + /* s1[i] != s2[i] in word, so we check byte 3. */ +.L_byte_check: + xtrb3 r0, r20 + xtrb3 r2, r21 + subu r0, r2 + bnez r0, .L_return + + /* check byte 2 */ + xtrb2 r0, r20 + xtrb2 r2, r21 + subu r0, r2 + bnez r0, .L_return + + /* check byte 1 */ + xtrb1 r0, r20 + xtrb1 r2, r21 + subu r0, r2 + bnez r0, .L_return + + /* check byte 0 */ + xtrb0 r0, r20 + xtrb0 r2, r21 + subu r0, r2 + br .L_return + + /* Compare when s1 is not aligned. */ +.L_s1_not_aligned: + sub r13, r19, r13 + sub r2, r13 +.L_s1_not_aligned_loop: + ldb r0, (r3, 0) + ldb r4, (r1, 0) + addi r3, 1 + subu r0, r4 + PRE_BNEZAD (r13) + addi r1, 1 + bnez r0, .L_return + BNEZAD (r13, .L_s1_not_aligned_loop) + br .L_s1_aligned +END (memcmp) +weak_alias (memcmp, bcmp) +libc_hidden_def (memcmp) +.weak memcmp |