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48 lines
1.3 KiB
Rust
48 lines
1.3 KiB
Rust
#![allow(dead_code)]
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use crate::alloc::{GlobalAlloc, Layout, System};
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use crate::cmp;
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use crate::ptr;
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// The minimum alignment guaranteed by the architecture. This value is used to
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// add fast paths for low alignment values.
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#[cfg(all(any(
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target_arch = "x86",
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target_arch = "arm",
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target_arch = "mips",
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target_arch = "powerpc",
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target_arch = "powerpc64",
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target_arch = "asmjs",
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target_arch = "wasm32",
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target_arch = "hexagon",
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target_arch = "riscv32"
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)))]
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pub const MIN_ALIGN: usize = 8;
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#[cfg(all(any(
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target_arch = "x86_64",
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target_arch = "aarch64",
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target_arch = "mips64",
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target_arch = "s390x",
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target_arch = "sparc64",
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target_arch = "riscv64"
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)))]
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pub const MIN_ALIGN: usize = 16;
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pub unsafe fn realloc_fallback(
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alloc: &System,
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ptr: *mut u8,
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old_layout: Layout,
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new_size: usize,
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) -> *mut u8 {
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// Docs for GlobalAlloc::realloc require this to be valid:
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let new_layout = Layout::from_size_align_unchecked(new_size, old_layout.align());
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let new_ptr = GlobalAlloc::alloc(alloc, new_layout);
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if !new_ptr.is_null() {
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let size = cmp::min(old_layout.size(), new_size);
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ptr::copy_nonoverlapping(ptr, new_ptr, size);
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GlobalAlloc::dealloc(alloc, ptr, old_layout);
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}
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new_ptr
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}
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