bjoernager/rust
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Cast pointers to usize before passing them to atomic operations as some platforms do not support atomic operations on pointers.

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This commit is contained in:
oli 2020-11-28 18:12:45 +00:00
parent 79fb037cc5
commit 392ea29757
2 changed files with 42 additions and 12 deletions
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49
compiler/rustc_codegen_ssa/src/mir/intrinsic.rs
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@ -439,14 +439,18 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
let ty = substs.type_at(0);
if int_type_width_signed(ty, bx.tcx()).is_some() || ty.is_unsafe_ptr() {
let weak = split[1] == "cxchgweak";
let pair = bx.atomic_cmpxchg(
args[0].immediate(),
args[1].immediate(),
args[2].immediate(),
order,
failorder,
weak,
);
let mut dst = args[0].immediate();
let mut cmp = args[1].immediate();
let mut src = args[2].immediate();
if ty.is_unsafe_ptr() {
// Some platforms do not support atomic operations on pointers,
// so we cast to integer first.
let ptr_llty = bx.type_ptr_to(bx.type_isize());
dst = bx.pointercast(dst, ptr_llty);
cmp = bx.ptrtoint(cmp, bx.type_isize());
src = bx.ptrtoint(src, bx.type_isize());
}
let pair = bx.atomic_cmpxchg(dst, cmp, src, order, failorder, weak);
let val = bx.extract_value(pair, 0);
let success = bx.extract_value(pair, 1);
let val = bx.from_immediate(val);
@ -465,8 +469,22 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
"load" => {
let ty = substs.type_at(0);
if int_type_width_signed(ty, bx.tcx()).is_some() || ty.is_unsafe_ptr() {
let size = bx.layout_of(ty).size;
bx.atomic_load(args[0].immediate(), order, size)
let layout = bx.layout_of(ty);
let size = layout.size;
let mut source = args[0].immediate();
if ty.is_unsafe_ptr() {
// Some platforms do not support atomic operations on pointers,
// so we cast to integer first...
let ptr_llty = bx.type_ptr_to(bx.type_isize());
source = bx.pointercast(source, ptr_llty);
}
let result = bx.atomic_load(source, order, size);
if ty.is_unsafe_ptr() {
// ... and then cast the result back to a pointer
bx.inttoptr(result, bx.backend_type(layout))
} else {
result
}
} else {
return invalid_monomorphization(ty);
}
@ -476,7 +494,16 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
let ty = substs.type_at(0);
if int_type_width_signed(ty, bx.tcx()).is_some() || ty.is_unsafe_ptr() {
let size = bx.layout_of(ty).size;
bx.atomic_store(args[1].immediate(), args[0].immediate(), order, size);
let mut val = args[1].immediate();
let mut ptr = args[0].immediate();
if ty.is_unsafe_ptr() {
// Some platforms do not support atomic operations on pointers,
// so we cast to integer first.
let ptr_llty = bx.type_ptr_to(bx.type_isize());
ptr = bx.pointercast(ptr, ptr_llty);
val = bx.ptrtoint(val, bx.type_isize());
}
bx.atomic_store(val, ptr, order, size);
return;
} else {
return invalid_monomorphization(ty);