compiler-builtins-zynq/src/mem.rs

67 lines
1.5 KiB
Rust

#[allow(warnings)]
#[cfg(target_pointer_width = "16")]
type c_int = i16;
#[allow(warnings)]
#[cfg(not(target_pointer_width = "16"))]
type c_int = i32;
#[no_mangle]
pub unsafe extern "C" fn memcpy(dest: *mut u8,
src: *const u8,
n: usize)
-> *mut u8 {
let mut i = 0;
while i < n {
*dest.offset(i as isize) = *src.offset(i as isize);
i += 1;
}
dest
}
#[no_mangle]
pub unsafe extern "C" fn memmove(dest: *mut u8,
src: *const u8,
n: usize)
-> *mut u8 {
if src < dest as *const u8 {
// copy from end
let mut i = n;
while i != 0 {
i -= 1;
*dest.offset(i as isize) = *src.offset(i as isize);
}
} else {
// copy from beginning
let mut i = 0;
while i < n {
*dest.offset(i as isize) = *src.offset(i as isize);
i += 1;
}
}
dest
}
#[no_mangle]
pub unsafe extern "C" fn memset(s: *mut u8, c: c_int, n: usize) -> *mut u8 {
let mut i = 0;
while i < n {
*s.offset(i as isize) = c as u8;
i += 1;
}
s
}
#[no_mangle]
pub unsafe extern "C" fn memcmp(s1: *const u8, s2: *const u8, n: usize) -> i32 {
let mut i = 0;
while i < n {
let a = *s1.offset(i as isize);
let b = *s2.offset(i as isize);
if a != b {
return a as i32 - b as i32;
}
i += 1;
}
0
}