Git conversion: Make reactos the root directory, move rosapps, rostests, wallpapers into modules, and delete rossubsys.

sdk/lib/crt/math/arm/__rt_div.c

@@ -0,0 +1,126 @@
+/*
+ * COPYRIGHT:       BSD - See COPYING.ARM in the top level directory
+ * PROJECT:         ReactOS CRT library
+ * FILE:            lib/sdk/crt/math/arm/__rt_div.c
+ * PURPOSE:         Implementation of __rt_udiv
+ * PROGRAMMER:      Timo Kreuzer
+ * REFERENCE:       http://research.microsoft.com/en-us/um/redmond/projects/invisible/src/crt/md/arm/_div10.s.htm
+ *                  http://research.microsoft.com/en-us/um/redmond/projects/invisible/src/crt/md/arm/_udiv.c.htm
+ */
+
+typedef struct _ARM_UDIVRESULT
+{
+    unsigned int quotient; /* to be returned in R0 */
+    unsigned int modulus;  /* to be returned in R1 */
+} ARM_UDIVRESULT;
+
+__forceinline
+void
+__brkdiv0(void)
+{
+    __emit(0xDEF9);
+}
+
+__forceinline
+void
+__rt_udiv_internal(
+    ARM_UDIVRESULT *result,
+    unsigned int divisor,
+    unsigned int dividend)
+{
+    unsigned int shift;
+    unsigned int mask;
+    unsigned int quotient;
+
+    if (divisor == 0)
+    {
+        /* Raise divide by zero error */
+        __brkdiv0();
+    }
+
+    if (divisor > dividend)
+    {
+        result->quotient = 0;
+        result->modulus = divisor;
+        return;
+    }
+
+    /* Get the difference in count of leading zeros between dividend and divisor */
+    shift = _CountLeadingZeros(divisor);
+    shift -= _CountLeadingZeros(dividend);
+
+    /* Shift the divisor to the left, so that it's highest bit is the same
+       as the highest bit of the dividend */
+    divisor <<= shift;
+
+    mask = 1 << shift;
+
+    quotient = 0;
+    do
+    {
+        if (dividend >= divisor)
+        {
+            quotient |= mask;
+            dividend -= divisor;
+        }
+        divisor >>= 1;
+        mask >>= 1;
+    }
+    while (mask);
+
+    result->quotient = quotient;
+    result->modulus = dividend;
+    return;
+}
+
+ARM_UDIVRESULT
+__rt_udiv(
+    unsigned int divisor,
+    unsigned int dividend)
+{
+    ARM_UDIVRESULT result;
+
+    __rt_udiv_internal(&result, divisor, dividend);
+    return result;
+}
+
+typedef struct _ARM_SDIVRESULT
+{
+    int quotient; /* to be returned in R0 */
+    int modulus;  /* to be returned in R1 */
+} ARM_SDIVRESULT;
+
+ARM_SDIVRESULT
+__rt_sdiv(
+    int divisor,
+    int dividend)
+{
+    ARM_SDIVRESULT result;
+    int divisor_sign, dividend_sign;
+
+    dividend_sign = divisor & 0x80000000;
+    if (dividend_sign)
+    {
+        dividend = -dividend;
+    }
+
+    divisor_sign = divisor & 0x80000000;
+    if (divisor_sign)
+    {
+        divisor = -divisor;
+    }
+
+    __rt_udiv_internal((ARM_UDIVRESULT*)&result, divisor, dividend);
+
+    if (dividend_sign ^ divisor_sign)
+    {
+        result.quotient = -result.quotient;
+    }
+
+    if (dividend_sign)
+    {
+        result.modulus = -result.modulus;
+    }
+
+    return result;
+}