linearize_assignment() emits confusing casts for compound assignments.
Consider p += 1, where p is a pointer.
oldvalue = cast_pseudo(ep, oldvalue, src->ctype, expr->ctype);
opcode = opcode_sign(op_trans[expr->op - SPECIAL_BASE], src->ctype);
dst = add_binary_op(ep, src->ctype, opcode, oldvalue, value);
value = cast_pseudo(ep, dst, expr->ctype, src->ctype);
It would make more sense to swap src->ctype and expr->ctype in both
cast_pseudo(ep, pseudo, from, to) calls:
In the first call, `oldvalue' is a pointer (expr->ctype), but it is
converted from an integer (src->ctype) to a pointer (expr->ctype);
In the second call, `dst' is an integer (src->ctype), but it is
converted from a pointer (expr->ctype) to an integer (src->ctype).
This patch instead converts `value' from an integer (src->ctype) to a
pointer (expr->ctype) so as to emit fewer casts.
Signed-off-by: Xi Wang <xi.wang@xxxxxxxxx>
---
linearize.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/linearize.c b/linearize.c
index 1d15cfd..d186387 100644
--- a/linearize.c
+++ b/linearize.c
@@ -1161,7 +1161,6 @@ static pseudo_t linearize_assignment(struct entrypoint *ep, struct expression *e
return value;
if (expr->op != '=') {
pseudo_t oldvalue = linearize_load_gen(ep, &ad);
- pseudo_t dst;
static const int op_trans[] = {
[SPECIAL_ADD_ASSIGN - SPECIAL_BASE] = OP_ADD,
[SPECIAL_SUB_ASSIGN - SPECIAL_BASE] = OP_SUB,
@@ -1179,10 +1178,9 @@ static pseudo_t linearize_assignment(struct entrypoint *ep, struct expression *e
if (!src)
return VOID;
- oldvalue = cast_pseudo(ep, oldvalue, src->ctype, expr->ctype);
- opcode = opcode_sign(op_trans[expr->op - SPECIAL_BASE], src->ctype);
- dst = add_binary_op(ep, src->ctype, opcode, oldvalue, value);
- value = cast_pseudo(ep, dst, expr->ctype, src->ctype);
+ opcode = opcode_sign(op_trans[expr->op - SPECIAL_BASE], expr->ctype);
+ value = cast_pseudo(ep, value, src->ctype, expr->ctype);
+ value = add_binary_op(ep, expr->ctype, opcode, oldvalue, value);
}
value = linearize_store_gen(ep, value, &ad);
finish_address_gen(ep, &ad);
--
1.7.9.5
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