arc/lib/strcmp-archs.S

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002 /*
0003  * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
0004  */
0005
0006 #include <linux/linkage.h>
0007
0008 ENTRY_CFI(strcmp)
0009     or  r2, r0, r1
0010     bmsk_s  r2, r2, 1
0011     brne    r2, 0, @.Lcharloop
0012
0013 ;;; s1 and s2 are word aligned
0014     ld.ab   r2, [r0, 4]
0015
0016     mov_s   r12, 0x01010101
0017     ror r11, r12
0018     .align  4
0019 .LwordLoop:
0020     ld.ab   r3, [r1, 4]
0021     ;; Detect NULL char in str1
0022     sub r4, r2, r12
0023     ld.ab   r5, [r0, 4]
0024     bic r4, r4, r2
0025     and r4, r4, r11
0026     brne.d.nt   r4, 0, .LfoundNULL
0027     ;; Check if the read locations are the same
0028     cmp r2, r3
0029     beq.d   .LwordLoop
0030     mov.eq  r2, r5
0031
0032     ;; A match is found, spot it out
0033 #ifdef __LITTLE_ENDIAN__
0034     swape   r3, r3
0035     mov_s   r0, 1
0036     swape   r2, r2
0037 #else
0038     mov_s   r0, 1
0039 #endif
0040     cmp_s   r2, r3
0041     j_s.d   [blink]
0042     bset.lo r0, r0, 31
0043
0044     .align 4
0045 .LfoundNULL:
0046 #ifdef __BIG_ENDIAN__
0047     swape   r4, r4
0048     swape   r2, r2
0049     swape   r3, r3
0050 #endif
0051     ;; Find null byte
0052     ffs r0, r4
0053     bmsk    r2, r2, r0
0054     bmsk    r3, r3, r0
0055     swape   r2, r2
0056     swape   r3, r3
0057     ;; make the return value
0058     sub.f   r0, r2, r3
0059     mov.hi  r0, 1
0060     j_s.d   [blink]
0061     bset.lo r0, r0, 31
0062
0063     .align 4
0064 .Lcharloop:
0065     ldb.ab  r2, [r0, 1]
0066     ldb.ab  r3, [r1, 1]
0067     nop
0068     breq    r2, 0, .Lcmpend
0069     breq    r2, r3, .Lcharloop
0070
0071     .align 4
0072 .Lcmpend:
0073     j_s.d   [blink]
0074     sub r0, r2, r3
0075 END_CFI(strcmp)