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Change memcmp and bcmp return type to c_int #980

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Merged
merged 4 commits into from
Jul 18, 2025
Merged

Change memcmp and bcmp return type to c_int #980

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d5775d7
Change memcmp and bcmp return type to c_int
supersurviveur Jul 18, 2025
0963b7c
Use core::ffi::c_int instead of crate::mem::c_int
supersurviveur Jul 18, 2025
c6af92d
Change as cast to From since the conversion is lossless
supersurviveur Jul 18, 2025
afae610
Import core::ffi::c_int
supersurviveur Jul 18, 2025
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5 changes: 3 additions & 2 deletions compiler-builtins/src/mem/impls.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@
// this use. Of course this is not a guarantee that such use will work, it just means that this
// crate doing wrapping pointer arithmetic with a method that must not wrap won't be the problem if
// something does go wrong at runtime.
use core::ffi::c_int;
use core::intrinsics::likely;

const WORD_SIZE: usize = core::mem::size_of::<usize>();
Expand Down Expand Up @@ -384,13 +385,13 @@ pub unsafe fn set_bytes(mut s: *mut u8, c: u8, mut n: usize) {
}

#[inline(always)]
pub unsafe fn compare_bytes(s1: *const u8, s2: *const u8, n: usize) -> i32 {
pub unsafe fn compare_bytes(s1: *const u8, s2: *const u8, n: usize) -> c_int {
let mut i = 0;
while i < n {
let a = *s1.wrapping_add(i);
let b = *s2.wrapping_add(i);
if a != b {
return a as i32 - b as i32;
return c_int::from(a) - c_int::from(b);
}
i += 1;
}
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4 changes: 2 additions & 2 deletions compiler-builtins/src/mem/mod.rs
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Expand Up @@ -37,12 +37,12 @@ intrinsics! {
}

#[mem_builtin]
pub unsafe extern "C" fn memcmp(s1: *const u8, s2: *const u8, n: usize) -> i32 {
pub unsafe extern "C" fn memcmp(s1: *const u8, s2: *const u8, n: usize) -> core::ffi::c_int {
impls::compare_bytes(s1, s2, n)
}

#[mem_builtin]
pub unsafe extern "C" fn bcmp(s1: *const u8, s2: *const u8, n: usize) -> i32 {
pub unsafe extern "C" fn bcmp(s1: *const u8, s2: *const u8, n: usize) -> core::ffi::c_int {
memcmp(s1, s2, n)
}

Expand Down