From 31c69b6ca1b91e7fd9fd8e14082fd2584c5f538c Mon Sep 17 00:00:00 2001
From: Toni Uhlig <matzeton@googlemail.com>
Date: Sun, 24 May 2020 16:48:22 +0200
Subject: first public release

Signed-off-by: Toni Uhlig <matzeton@googlemail.com>
---
 source/math.c | 135 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 135 insertions(+)
 create mode 100644 source/math.c

(limited to 'source/math.c')

diff --git a/source/math.c b/source/math.c
new file mode 100644
index 0000000..c8eafee
--- /dev/null
+++ b/source/math.c
@@ -0,0 +1,135 @@
+#include "compat.h"
+#include "math.h"
+
+
+uint64_t __udivmoddi4(uint64_t num, uint64_t den, uint64_t * rem_p)
+{
+    uint64_t quot = 0, qbit = 1;
+
+    if (den == 0) {
+	asm volatile ("int $0");
+	return 0;		/* If trap returns... */
+    }
+
+    /* Left-justify denominator and count shift */
+    while ((int64_t) den >= 0) {
+	den <<= 1;
+	qbit <<= 1;
+    }
+
+    while (qbit) {
+	if (den <= num) {
+	    num -= den;
+	    quot += qbit;
+	}
+	den >>= 1;
+	qbit >>= 1;
+    }
+
+    if (rem_p)
+	*rem_p = num;
+
+    return quot;
+}
+
+/* slightly modified version from
+ *   https://code.google.com/p/embox/source/browse/trunk/embox/src/lib/gcc
+ *   _thx_
+ */
+
+UINT64 __udivdi3(UINT64 num, UINT64 den)
+{
+    UINT64 result = 0;
+    int steps;
+
+    if (den == 0)
+    {
+        return 0;
+    }
+
+    steps = 0;
+    result = 0;
+
+    while (!(den & 0x8000000000000000))
+    {
+        den <<= 1;
+        ++steps;
+    }
+
+    do
+    {
+        result <<= 1;
+        if (num >= den)
+        {
+            result |= 1;
+            num -= den;
+        }
+        den >>= 1;
+    }
+    while (steps--);
+
+    return result;
+}
+
+INT64 __divdi3(INT64 num, INT64 den)
+{
+    INT64 quot;
+    int neg;
+
+    num = num < 0 ? (neg = 1, -num) : (neg = 0, num);
+    den = den < 0 ? (neg ^= 1, -den) : den;
+
+    quot = __udivdi3(num, den);
+
+    return neg ? -quot : quot;
+}
+
+INT64 __moddi3(INT64 num, INT64 den)
+{
+    INT64 rem;
+    int neg;
+
+    num = num < 0 ? (neg = 1, -num) : (neg = 0, num);
+    den = den < 0 ? (neg ^= 1, -den) : den;
+
+    rem = __umoddi3(num, den);
+
+    return neg ? -rem : rem;
+}
+
+UINT64 __umoddi3(UINT64 num, UINT64 den)
+{
+    int steps;
+
+    if (den == 0)
+    {
+        return 0;
+    }
+
+    steps = 0;
+
+    while (!(den & 0x8000000000000000))
+    {
+        den <<= 1;
+        ++steps;
+    }
+
+    do
+    {
+        if (num >= den)
+        {
+            num -= den;
+        }
+        den >>= 1;
+    }
+    while (steps--);
+
+    return num;
+}
+
+size_t __pow(size_t x, size_t n)
+{
+    if (n > 0) {
+      return x*__pow(x, n-1);
+    } else return 1;
+}
-- 
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