Signed-off-by: Luis Pires
---
include/qemu/host-utils.h | 38 ++
1 file changed, 38 insertions(+)
diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h
index 6f18b29921..9f40077083 100644
--- a/include/qemu/host-utils.h
+++ b/include/qemu/host-utils.h
@@ -588,6 +588,44 @@ static inline bool umul64_overflow(uint64_t x, uint64_t y,
uint64_t *ret)
#endif
}
+/*
+ * Unsigned 128x64 multiplication.
+ * Returns true if the result got truncated to 128 bits.
+ * Otherwise, returns false and the multiplication result via plow and phigh.
+ */
+static inline bool mulu128(uint64_t *plow, uint64_t *phigh, uint64_t factor)
+{
+#if defined(CONFIG_INT128) && \
+(__has_builtin(__builtin_mul_overflow) || __GNUC__ >= 5)
+bool res;
+__uint128_t r;
+__uint128_t f = ((__uint128_t)*phigh << 64) | *plow;
+res = __builtin_mul_overflow(f, factor, &r);
+
+*plow = r;
+*phigh = r >> 64;
+
+return res;
+#else
+uint64_t dhi = *phigh;
+uint64_t dlo = *plow;
+uint64_t ahi;
+uint64_t blo, bhi;
+
+if (dhi == 0) {
+mulu64(plow, phigh, dlo, factor);
+return false;
+}
+
+mulu64(plow, &ahi, dlo, factor);
+mulu64(&blo, &bhi, dhi, factor);
+
+*phigh = ahi + blo;
+
+return (bhi > 0) || (*phigh < ahi);
+#endif
+}
+
/**
* uadd64_carry - addition with carry-in and carry-out
* @x, @y: addends
--
2.25.1