* THE SOFTWARE.
*/
-#include <stdlib.h>
-#include <stdint.h>
+#include "qemu/osdep.h"
#include "qemu/host-utils.h"
-/* Long integer helpers */
#ifndef CONFIG_INT128
+/* Long integer helpers */
static inline void mul64(uint64_t *plow, uint64_t *phigh,
uint64_t a, uint64_t b)
{
}
*phigh = rh;
}
-#endif /* !CONFIG_INT128 */
+
+/* Unsigned 128x64 division. Returns 1 if overflow (divide by zero or */
+/* quotient exceeds 64 bits). Otherwise returns quotient via plow and */
+/* remainder via phigh. */
+int divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor)
+{
+ uint64_t dhi = *phigh;
+ uint64_t dlo = *plow;
+ unsigned i;
+ uint64_t carry = 0;
+
+ if (divisor == 0) {
+ return 1;
+ } else if (dhi == 0) {
+ *plow = dlo / divisor;
+ *phigh = dlo % divisor;
+ return 0;
+ } else if (dhi > divisor) {
+ return 1;
+ } else {
+
+ for (i = 0; i < 64; i++) {
+ carry = dhi >> 63;
+ dhi = (dhi << 1) | (dlo >> 63);
+ if (carry || (dhi >= divisor)) {
+ dhi -= divisor;
+ carry = 1;
+ } else {
+ carry = 0;
+ }
+ dlo = (dlo << 1) | carry;
+ }
+
+ *plow = dlo;
+ *phigh = dhi;
+ return 0;
+ }
+}
+
+int divs128(int64_t *plow, int64_t *phigh, int64_t divisor)
+{
+ int sgn_dvdnd = *phigh < 0;
+ int sgn_divsr = divisor < 0;
+ int overflow = 0;
+
+ if (sgn_dvdnd) {
+ *plow = ~(*plow);
+ *phigh = ~(*phigh);
+ if (*plow == (int64_t)-1) {
+ *plow = 0;
+ (*phigh)++;
+ } else {
+ (*plow)++;
+ }
+ }
+
+ if (sgn_divsr) {
+ divisor = 0 - divisor;
+ }
+
+ overflow = divu128((uint64_t *)plow, (uint64_t *)phigh, (uint64_t)divisor);
+
+ if (sgn_dvdnd ^ sgn_divsr) {
+ *plow = 0 - *plow;
+ }
+
+ if (!overflow) {
+ if ((*plow < 0) ^ (sgn_dvdnd ^ sgn_divsr)) {
+ overflow = 1;
+ }
+ }
+
+ return overflow;
+}
+#endif
+
+/**
+ * urshift - 128-bit Unsigned Right Shift.
+ * @plow: in/out - lower 64-bit integer.
+ * @phigh: in/out - higher 64-bit integer.
+ * @shift: in - bytes to shift, between 0 and 127.
+ *
+ * Result is zero-extended and stored in plow/phigh, which are
+ * input/output variables. Shift values outside the range will
+ * be mod to 128. In other words, the caller is responsible to
+ * verify/assert both the shift range and plow/phigh pointers.
+ */
+void urshift(uint64_t *plow, uint64_t *phigh, int32_t shift)
+{
+ shift &= 127;
+ if (shift == 0) {
+ return;
+ }
+
+ uint64_t h = *phigh >> (shift & 63);
+ if (shift >= 64) {
+ *plow = h;
+ *phigh = 0;
+ } else {
+ *plow = (*plow >> (shift & 63)) | (*phigh << (64 - (shift & 63)));
+ *phigh = h;
+ }
+}
+
+/**
+ * ulshift - 128-bit Unsigned Left Shift.
+ * @plow: in/out - lower 64-bit integer.
+ * @phigh: in/out - higher 64-bit integer.
+ * @shift: in - bytes to shift, between 0 and 127.
+ * @overflow: out - true if any 1-bit is shifted out.
+ *
+ * Result is zero-extended and stored in plow/phigh, which are
+ * input/output variables. Shift values outside the range will
+ * be mod to 128. In other words, the caller is responsible to
+ * verify/assert both the shift range and plow/phigh pointers.
+ */
+void ulshift(uint64_t *plow, uint64_t *phigh, int32_t shift, bool *overflow)
+{
+ uint64_t low = *plow;
+ uint64_t high = *phigh;
+
+ shift &= 127;
+ if (shift == 0) {
+ return;
+ }
+
+ /* check if any bit will be shifted out */
+ urshift(&low, &high, 128 - shift);
+ if (low | high) {
+ *overflow = true;
+ }
+
+ if (shift >= 64) {
+ *phigh = *plow << (shift & 63);
+ *plow = 0;
+ } else {
+ *phigh = (*plow >> (64 - (shift & 63))) | (*phigh << (shift & 63));
+ *plow = *plow << shift;
+ }
+}