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Use bitcast to transmute where possible

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This commit is contained in:
bjorn3 2020-03-29 12:03:30 +02:00
parent 9cf1bcea5c
commit dfb5d16fb3
1 changed files with 23 additions and 6 deletions
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29
src/intrinsics/mod.rs
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@ -631,12 +631,29 @@ pub(crate) fn codegen_intrinsic_call<'tcx>(
ret.write_cvalue(fx, CValue::by_val(res, base.layout()));
};
transmute, <src_ty, dst_ty> (c from) {
assert_eq!(from.layout().ty, src_ty);
let (addr, meta) = from.force_stack(fx);
assert!(meta.is_none());
let dst_layout = fx.layout_of(dst_ty);
ret.write_cvalue(fx, CValue::by_ref(addr, dst_layout))
transmute, (c from) {
assert_eq!(from.layout().size, ret.layout().size);
if from.layout().ty.kind == ret.layout().ty.kind {
ret.write_cvalue(fx, from);
} else if let (Some(src_ty), Some(dst_ty)) = (fx.clif_type(from.layout().ty), fx.clif_type(ret.layout().ty)) {
let from = from.load_scalar(fx);
let val = match (src_ty, dst_ty) {
(_, _) if src_ty == dst_ty => from,
(types::I32, types::F32) | (types::F32, types::I32)
| (types::I64, types::F64) | (types::F64, types::I64) => {
fx.bcx.ins().bitcast(dst_ty, from)
}
(_, _) if src_ty.is_vector() && dst_ty.is_vector() => {
fx.bcx.ins().raw_bitcast(dst_ty, from)
}
_ => unreachable!("{:?} -> {:?}", src_ty, dst_ty),
};
ret.write_cvalue(fx, CValue::by_val(val, ret.layout()));
} else {
let (addr, meta) = from.force_stack(fx);
assert!(meta.is_none());
ret.write_cvalue(fx, CValue::by_ref(addr, ret.layout()));
}
};
write_bytes, (c dst, v val, v count) {
let pointee_ty = dst.layout().ty.builtin_deref(true).unwrap().ty;