const out_val *gen_expr_assign_compound(const expr *e, out_ctx *octx)
{
/* int += float
* lea int, cast up to float, add, cast down to int, store
*/
const out_val *saved_post = NULL, *addr_lhs, *rhs, *lhs, *result;
addr_lhs = gen_expr(e->lhs, octx);
out_val_retain(octx, addr_lhs); /* 2 */
if(e->assign_is_post){
out_val_retain(octx, addr_lhs); /* 3 */
saved_post = out_deref(octx, addr_lhs); /* addr_lhs=2, saved_post=1 */
}
/* delay the dereference until after generating rhs.
* this is fine, += etc aren't sequence points
*/
rhs = gen_expr(e->rhs, octx);
/* here's the delayed dereference */
lhs = out_deref(octx, addr_lhs); /* addr_lhs=1 */
if(e->bits.compoundop.upcast_ty)
lhs = out_cast(octx, lhs, e->bits.compoundop.upcast_ty, /*normalise_bool:*/1);
result = out_op(octx, e->bits.compoundop.op, lhs, rhs);
gen_op_trapv(e->tree_type, &result, octx, e->bits.compoundop.op);
if(e->bits.compoundop.upcast_ty) /* need to cast back down to store */
result = out_cast(octx, result, e->tree_type, /*normalise_bool:*/1);
if(!saved_post)
out_val_retain(octx, result);
out_store(octx, addr_lhs, result);
if(!saved_post)
return result;
return saved_post;
}
void gen_expr_assign_compound(expr *e)
{
/* int += float
* lea int, cast up to float, add, cast down to int, store
*/
lea_expr(e->bits.compound_upcast ? expr_cast_child(e->lhs) : e->lhs);
if(e->assign_is_post){
out_dup();
out_deref();
out_flush_volatile();
out_swap();
out_comment("saved for compound op");
}
out_dup();
/* delay the dereference until after generating rhs.
* this is fine, += etc aren't sequence points
*/
gen_expr(e->rhs);
/* here's the delayed dereference */
out_swap();
out_deref();
if(e->bits.compound_upcast)
out_cast(e->lhs->tree_type, /*normalise_bool:*/1);
out_swap();
out_op(e->op);
if(e->bits.compound_upcast) /* need to cast back down to store */
out_cast(e->tree_type, /*normalise_bool:*/1);
out_store();
if(e->assign_is_post)
out_pop();
}