diff options
Diffstat (limited to 'newlib/libc/machine/rx/memchr.S')
| -rw-r--r-- | newlib/libc/machine/rx/memchr.S | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/newlib/libc/machine/rx/memchr.S b/newlib/libc/machine/rx/memchr.S index 937753cef..cdc97c874 100644 --- a/newlib/libc/machine/rx/memchr.S +++ b/newlib/libc/machine/rx/memchr.S @@ -5,9 +5,28 @@ .global _memchr .type _memchr,@function _memchr: + ;; R1: string pointer + ;; R2: byte sought + ;; R3: max number to scan +#ifdef __RX_DISALLOW_STRING_INSNS__ + mov.b r2, r2 ; The mov.b below sign extends as it loads, so make sure that r2 is sign-extended as well. +2: cmp #0, r3 + beq 1f + sub #1, r3 + mov.b [r1+], r5 + cmp r5, r2 + bne 2b + + sub #1, r1 ; We have found a match, bit now R1 points to the byte after the match. +1: rts +#else cmp #0, r3 ; If r3 is 0 suntil.b will do nothing and not set any flags... stz #1, r1 ; ...so store 1 into r1. It will be decremented by the SUB later. suntil.b ; Search until *r1 == r2 or r3 bytes have been examined. stnz #1, r1 ; If no match was found return NULL. sub #1, r1 ; suntil.b leaves r1 pointing at the address *after* the match. rts +#endif + + .size _memchr, . - _memchr + |