diff options
Diffstat (limited to 'newlib/libc/machine/rx/memmove.S')
| -rw-r--r-- | newlib/libc/machine/rx/memmove.S | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/newlib/libc/machine/rx/memmove.S b/newlib/libc/machine/rx/memmove.S index 4b126bafc..60b76836b 100644 --- a/newlib/libc/machine/rx/memmove.S +++ b/newlib/libc/machine/rx/memmove.S @@ -4,6 +4,39 @@ .global _memmove .type _memmove,@function _memmove: + ;; R1: DEST + ;; R2: SRC + ;; R3: COUNT +#ifdef __RX_DISALLOW_STRING_INSNS__ + /* Do not use the string instructions - they might prefetch + bytes from outside of valid memory. This is particularly + dangerous in I/O space. */ + + cmp #0, r3 ; If the count is zero, do nothing + beq 4f + + cmp r1, r2 + blt 3f ; If SRC < DEST copy backwards + + mov r1, r14 ; Save a copy of DEST + +5: mov.b [r2+], r5 + mov.b r5, [r14+] + sub #1, r3 + bne 5b + +4: rts + +3: add r3, r1 + add r3, r2 + +6: mov.b [-r2], r5 + mov.b r5, [-r1] + sub #1, r3 + bne 6b + + rts +#else mov r1, r4 ; Save a copy of DEST cmp r1, r2 blt 2f ; If SRC (r2) is less than DEST (r1) then copy backwards @@ -18,3 +51,7 @@ _memmove: sub #1, r1 ; additions and subtractions. smovb bra 1b + +#endif /* SMOVF allowed. */ + + .size _memmove, . - _memmove |