1 files changed, 63 insertions, 0 deletions
diff --git a/src/civetweb/src/third_party/duktape-1.5.2/src-separate/duk_util_tinyrandom.c b/src/civetweb/src/third_party/duktape-1.5.2/src-separate/duk_util_tinyrandom.c
new file mode 100644
index 000000000..99e4223c5
--- /dev/null
+++ b/src/civetweb/src/third_party/duktape-1.5.2/src-separate/duk_util_tinyrandom.c
@@ -0,0 +1,63 @@
+/*
+ *  A tiny random number generator.
+ *
+ *  Currently used for Math.random().
+ *
+ *  http://www.woodmann.com/forum/archive/index.php/t-3100.html
+ */
+
+#include "duk_internal.h"
+
+#define DUK__UPDATE_RND(rnd) do { \
+		(rnd) += ((rnd) * (rnd)) | 0x05; \
+		(rnd) = ((rnd) & 0xffffffffU);       /* if duk_uint32_t is exactly 32 bits, this is a NOP */ \
+	} while (0)
+
+#define DUK__RND_BIT(rnd)  ((rnd) >> 31)  /* only use the highest bit */
+
+DUK_INTERNAL duk_uint32_t duk_util_tinyrandom_get_bits(duk_hthread *thr, duk_small_int_t n) {
+	duk_small_int_t i;
+	duk_uint32_t res = 0;
+	duk_uint32_t rnd;
+
+	rnd = thr->heap->rnd_state;
+
+	for (i = 0; i < n; i++) {
+		DUK__UPDATE_RND(rnd);
+		res <<= 1;
+		res += DUK__RND_BIT(rnd);
+	}
+
+	thr->heap->rnd_state = rnd;
+
+	return res;
+}
+
+DUK_INTERNAL duk_double_t duk_util_tinyrandom_get_double(duk_hthread *thr) {
+	duk_double_t t;
+	duk_small_int_t n;
+	duk_uint32_t rnd;
+
+	/*
+	 *  XXX: could make this a lot faster if we create the double memory
+	 *  representation directly.  Feasible easily (must be uniform random).
+	 */
+
+	rnd = thr->heap->rnd_state;
+
+	n = 53;  /* enough to cover the whole mantissa */
+	t = 0.0;
+
+	do {
+		DUK__UPDATE_RND(rnd);
+		t += DUK__RND_BIT(rnd);
+		t /= 2.0;
+	} while (--n);
+
+	thr->heap->rnd_state = rnd;
+
+	DUK_ASSERT(t >= (duk_double_t) 0.0);
+	DUK_ASSERT(t < (duk_double_t) 1.0);
+
+	return t;
+}