OpenE2K
/
rust
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Avoid unnecessary temporary on assignments 

We only need the temporary when the type needs to be dropped, for other
types, we can use trans_into to directly place the value into the
destination.
This commit is contained in:
Björn Steinbrink 2014-06-22 15:32:55 +02:00 committed by Alex Crichton
parent e4e3550ff6
commit a0ec902e23
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
src/librustc/middle/trans/expr.rs
View File

@ -610,7 +610,6 @@ fn trans_rvalue_stmt_unadjusted<'a>(bcx: &'a Block<'a>,
controlflow::trans_loop(bcx, expr.id, &**body)
}
ast::ExprAssign(ref dst, ref src) => {
let src_datum = unpack_datum!(bcx, trans(bcx, &**src));
let dst_datum = unpack_datum!(bcx, trans_to_lvalue(bcx, &**dst, "assign"));
if ty::type_needs_drop(bcx.tcx(), dst_datum.ty) {
@ -630,12 +629,13 @@ fn trans_rvalue_stmt_unadjusted<'a>(bcx: &'a Block<'a>,
//
// We could avoid this intermediary with some analysis
// to determine whether `dst` may possibly own `src`.
let src_datum = unpack_datum!(bcx, trans(bcx, &**src));
let src_datum = unpack_datum!(
bcx, src_datum.to_rvalue_datum(bcx, "ExprAssign"));
bcx = glue::drop_ty(bcx, dst_datum.val, dst_datum.ty);
src_datum.store_to(bcx, dst_datum.val)
} else {
src_datum.store_to(bcx, dst_datum.val)
trans_into(bcx, &**src, SaveIn(dst_datum.to_llref()))
}
}
ast::ExprAssignOp(op, ref dst, ref src) => {