Last change
on this file was
444,
checked in by satin@…, 6 years ago
|
add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc
|
File size:
1004 bytes
|
Rev | Line | |
---|
[444] | 1 | .file "strncpy.S" |
---|
| 2 | |
---|
| 3 | .section .text |
---|
| 4 | .global _strncpy |
---|
| 5 | .type _strncpy,@function |
---|
| 6 | _strncpy: |
---|
| 7 | #ifdef __RX_DISALLOW_STRING_INSNS__ |
---|
| 8 | cmp #0, r3 |
---|
| 9 | beq 3f |
---|
| 10 | |
---|
| 11 | mov r1, r4 ; Preserve R1 for the return value. |
---|
| 12 | |
---|
| 13 | 2: mov.b [r2+], r5 ; Copy bytes until... |
---|
| 14 | mov.b r5, [r4+] |
---|
| 15 | sub #1, r3 |
---|
| 16 | beq 3f ; ... our count reaches zero |
---|
| 17 | cmp #0, r5 |
---|
| 18 | bne 2b ; ... or we have written a NUL byte |
---|
| 19 | |
---|
| 20 | 4: mov.b r5, [r4+] ; Continue to write further NUL bytes |
---|
| 21 | sub #1, r3 |
---|
| 22 | bne 4b ; until the count reaches zero. |
---|
| 23 | |
---|
| 24 | 3: rts |
---|
| 25 | |
---|
| 26 | #else |
---|
| 27 | mov r1, r4 ; Save a copy of the dest pointer. |
---|
| 28 | mov r3, r5 ; Save a copy of the byte count |
---|
| 29 | smovu ; Copy the bytes |
---|
| 30 | cmp #0, r3 ; If we have copied the number of bytes requested |
---|
| 31 | beq 1f ; then skip the next bit: |
---|
| 32 | add r4, r5, r1 ; Point to the last byte that we are supposed to write. |
---|
| 33 | sub r3, r1 ; Subtract the number of bytes left to be written. |
---|
| 34 | mov #0, r2 ; Fill the remaining bytes with NULs, |
---|
| 35 | sstr.b |
---|
| 36 | 1: |
---|
| 37 | mov r4, r1 ; Return the destination pointer |
---|
| 38 | rts |
---|
| 39 | #endif |
---|
| 40 | .size _strncpy, . - _strncpy |
---|
| 41 | |
---|
Note: See
TracBrowser
for help on using the repository browser.