parent
adfb1ff851
commit
265939fc00
@ -1,10 +1,12 @@
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#![allow(unused_features)]
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#![feature(asm)]
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#![feature(core_intrinsics)]
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#![feature(linkage)]
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#![feature(naked_functions)]
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#![cfg_attr(not(test), no_std)]
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// TODO(rust-lang/rust#35021) uncomment when that PR lands
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// #![feature(rustc_builtins)]
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#![no_builtins]
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// We disable #[no_mangle] for tests so that we can verify the test results
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// against the native compiler-rt implementations of the builtins.
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@ -20,6 +22,7 @@ extern crate core;
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pub mod arm;
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pub mod udiv;
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pub mod mem;
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pub mod mul;
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pub mod shift;
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60
src/mem.rs
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60
src/mem.rs
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@ -0,0 +1,60 @@
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// NOTE Copied verbatim from the rlibc crate
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// cf. https://crates.io/crates/rlibc
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#[linkage = "weak"]
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#[no_mangle]
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pub unsafe extern "C" fn memcpy(dest: *mut u8, src: *const u8, n: usize) -> *mut u8 {
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let mut i = 0;
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while i < n {
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*dest.offset(i as isize) = *src.offset(i as isize);
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i += 1;
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}
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dest
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}
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#[linkage = "weak"]
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#[no_mangle]
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pub unsafe extern "C" fn memmove(dest: *mut u8, src: *const u8, n: usize) -> *mut u8 {
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if src < dest as *const u8 {
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// copy from end
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let mut i = n;
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while i != 0 {
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i -= 1;
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*dest.offset(i as isize) = *src.offset(i as isize);
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}
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} else {
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// copy from beginning
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let mut i = 0;
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while i < n {
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*dest.offset(i as isize) = *src.offset(i as isize);
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i += 1;
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}
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}
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dest
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}
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#[linkage = "weak"]
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#[no_mangle]
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pub unsafe extern "C" fn memset(s: *mut u8, c: i32, n: usize) -> *mut u8 {
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let mut i = 0;
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while i < n {
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*s.offset(i as isize) = c as u8;
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i += 1;
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}
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s
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}
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#[linkage = "weak"]
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#[no_mangle]
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pub unsafe extern "C" fn memcmp(s1: *const u8, s2: *const u8, n: usize) -> i32 {
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let mut i = 0;
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while i < n {
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let a = *s1.offset(i as isize);
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let b = *s2.offset(i as isize);
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if a != b {
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return a as i32 - b as i32;
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}
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i += 1;
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}
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0
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}
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