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-rw-r--r--libquanta_bigint_divmod_small__.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/libquanta_bigint_divmod_small__.c b/libquanta_bigint_divmod_small__.c
new file mode 100644
index 0000000..a2c345f
--- /dev/null
+++ b/libquanta_bigint_divmod_small__.c
@@ -0,0 +1,34 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+uintmax_t
+libquanta_bigint_divmod_small__(struct bigint *big, uintmax_t small)
+{
+ uintmax_t q = 0, hi, lo;
+ int e = 8 * (int)sizeof(small);
+
+#if 0 /* this would overflow (undefined behaviour) and not fit in the result */
+ q = big->high / small;
+ q <<= 8 * (int)sizeof(small);
+#endif
+ big->high %= small;
+
+ while (big->high && --e) {
+ hi = small >> (8 * (int)sizeof(small) - e);
+ lo = small << e;
+
+ if (hi > big->high)
+ continue;
+ if (hi == big->high && lo > big->low)
+ continue;
+
+ q |= (uintmax_t)1 << e;
+ bigint_sub_small(big, lo);
+ big->high -= hi;
+ }
+
+ q += big->low / small;
+ big->low %= small;
+ return q;
+}