host-utils: fix missing zero-extension in divs128

*plow (lower 64 bits of the dividend) is passed into divs128() as
a signed 64-bit integer. When building an __int128_t from it, it
must be zero-extended, instead of sign-extended.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Luis Pires <luis.pires@eldorado.org.br>
Message-Id: <20210910112624.72748-3-luis.pires@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Luis Pires 2021-09-10 08:26:04 -03:00 committed by David Gibson
parent 06c0259a08
commit 4ff2a971f4

View file

@ -70,7 +70,7 @@ static inline int divs128(int64_t *plow, int64_t *phigh, int64_t divisor)
if (divisor == 0) {
return 1;
} else {
__int128_t dividend = ((__int128_t)*phigh << 64) | *plow;
__int128_t dividend = ((__int128_t)*phigh << 64) | (uint64_t)*plow;
__int128_t result = dividend / divisor;
*plow = result;
*phigh = dividend % divisor;