Skip to content

trans_arg_expr: Omit extra copies for rvalues #8262

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

trans_arg_expr: Omit extra copies for rvalues #8262

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
75 changes: 24 additions & 51 deletions src/librustc/middle/trans/callee.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -834,60 +834,33 @@ pub fn trans_arg_expr(bcx: @mut Block,
val = arg_datum.to_ref_llval(bcx);
}
DontAutorefArg => {
match self_mode {
let need_scratch = ty::type_needs_drop(bcx.tcx(), arg_datum.ty) ||
(bcx.expr_is_lval(arg_expr) &&
arg_datum.appropriate_mode(bcx.tcx()).is_by_ref());

let arg_datum = if need_scratch {
let scratch = scratch_datum(bcx, arg_datum.ty, "__self", false);
arg_datum.store_to_datum(bcx, INIT, scratch);

// Technically, ownership of val passes to the callee.
// However, we must cleanup should we fail before the
// callee is actually invoked.
scratch.add_clean(bcx);
temp_cleanups.push(scratch.val);

scratch
} else {
arg_datum
};

val = match self_mode {
ty::ByRef => {
// This assertion should really be valid, but because
// the explicit self code currently passes by-ref, it
// does not hold.
//
//assert !bcx.ccx().maps.moves_map.contains_key(
// &arg_expr.id);
debug!("by ref arg with type %s, storing to scratch",
bcx.ty_to_str(arg_datum.ty));
let scratch = scratch_datum(bcx, arg_datum.ty,
"__self", false);

arg_datum.store_to_datum(bcx,
INIT,
scratch);

// Technically, ownership of val passes to the callee.
// However, we must cleanup should we fail before the
// callee is actually invoked.
scratch.add_clean(bcx);
temp_cleanups.push(scratch.val);

val = scratch.to_ref_llval(bcx);
debug!("by ref arg with type %s", bcx.ty_to_str(arg_datum.ty));
arg_datum.to_ref_llval(bcx)
}
ty::ByCopy => {
if ty::type_needs_drop(bcx.tcx(), arg_datum.ty) ||
arg_datum.appropriate_mode(bcx.tcx()).is_by_ref() {
debug!("by copy arg with type %s, storing to scratch",
bcx.ty_to_str(arg_datum.ty));
let scratch = scratch_datum(bcx, arg_datum.ty,
"__arg", false);

arg_datum.store_to_datum(bcx,
INIT,
scratch);

// Technically, ownership of val passes to the callee.
// However, we must cleanup should we fail before the
// callee is actually invoked.
scratch.add_clean(bcx);
temp_cleanups.push(scratch.val);

match scratch.appropriate_mode(bcx.tcx()) {
ByValue => val = Load(bcx, scratch.val),
ByRef(_) => val = scratch.val,
}
} else {
debug!("by copy arg with type %s", bcx.ty_to_str(arg_datum.ty));
match arg_datum.mode {
ByRef(_) => val = Load(bcx, arg_datum.val),
ByValue => val = arg_datum.val,
}
}
debug!("by copy arg with type %s", bcx.ty_to_str(arg_datum.ty));
arg_datum.to_appropriate_llval(bcx)
}
}
}
Expand Down