summaryrefslogtreecommitdiffstats
path: root/qemu/util/host-utils.c
diff options
context:
space:
mode:
Diffstat (limited to 'qemu/util/host-utils.c')
-rw-r--r--qemu/util/host-utils.c162
1 files changed, 162 insertions, 0 deletions
diff --git a/qemu/util/host-utils.c b/qemu/util/host-utils.c
new file mode 100644
index 000000000..102e5bf30
--- /dev/null
+++ b/qemu/util/host-utils.c
@@ -0,0 +1,162 @@
+/*
+ * Utility compute operations used by translated code.
+ *
+ * Copyright (c) 2003 Fabrice Bellard
+ * Copyright (c) 2007 Aurelien Jarno
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdlib.h>
+#include <stdint.h>
+#include "qemu/host-utils.h"
+
+/* Long integer helpers */
+static inline void mul64(uint64_t *plow, uint64_t *phigh,
+ uint64_t a, uint64_t b)
+{
+ typedef union {
+ uint64_t ll;
+ struct {
+#ifdef HOST_WORDS_BIGENDIAN
+ uint32_t high, low;
+#else
+ uint32_t low, high;
+#endif
+ } l;
+ } LL;
+ LL rl, rm, rn, rh, a0, b0;
+ uint64_t c;
+
+ a0.ll = a;
+ b0.ll = b;
+
+ rl.ll = (uint64_t)a0.l.low * b0.l.low;
+ rm.ll = (uint64_t)a0.l.low * b0.l.high;
+ rn.ll = (uint64_t)a0.l.high * b0.l.low;
+ rh.ll = (uint64_t)a0.l.high * b0.l.high;
+
+ c = (uint64_t)rl.l.high + rm.l.low + rn.l.low;
+ rl.l.high = c;
+ c >>= 32;
+ c = c + rm.l.high + rn.l.high + rh.l.low;
+ rh.l.low = c;
+ rh.l.high += (uint32_t)(c >> 32);
+
+ *plow = rl.ll;
+ *phigh = rh.ll;
+}
+
+/* Unsigned 64x64 -> 128 multiplication */
+void mulu64 (uint64_t *plow, uint64_t *phigh, uint64_t a, uint64_t b)
+{
+ mul64(plow, phigh, a, b);
+}
+
+/* Signed 64x64 -> 128 multiplication */
+void muls64 (uint64_t *plow, uint64_t *phigh, int64_t a, int64_t b)
+{
+ uint64_t rh;
+
+ mul64(plow, &rh, a, b);
+
+ /* Adjust for signs. */
+ if (b < 0) {
+ rh -= a;
+ }
+ if (a < 0) {
+ rh -= b;
+ }
+ *phigh = rh;
+}
+
+/* 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;
+}
+