On 2020/3/14 14:52, Richard Henderson wrote:
On 3/12/20 7:58 AM, LIU Zhiwei wrote:
+static int64_t do_mulhsu_d(int64_t s2, uint64_t s1)
+{
+ uint64_t hi_64, lo_64, abs_s2 = s2;
+
+ if (s2 < 0) {
+ abs_s2 = -s2;
+ }
+ mulu64(&lo_64, &hi_64, abs_s2, s1);
+ if ((int64_t)(s2 ^ s1) < 0) {
Why would the sign of s1 be relevant?
It's always unsigned.
Yes, it is a bug. Thanks for pointing that.
Zhiwei
We have code for this in e.g. tcg_gen_mulsu2_i64
mulu4(&lo, &hi, s1, s2);
if ((int64_t)s2 < 0) {
hi -= s2;
}
r~
