[tkreuzer] 67178: [CRT] Implement __rt_udiv in C.

Author: tkreuzer
Date: Sun Apr 12 17:08:11 2015
New Revision: 67178

URL: http://svn.reactos.org/svn/reactos?rev=67178&view=rev
Log:
[CRT]
Implement __rt_udiv in C.

Added:
    trunk/reactos/lib/sdk/crt/math/arm/__rt_udiv.c   (with props)
Removed:
    trunk/reactos/lib/sdk/crt/math/arm/__rt_udiv.s
Modified:
    trunk/reactos/lib/sdk/crt/crt.cmake
    trunk/reactos/lib/sdk/crt/libcntpr.cmake

Modified: trunk/reactos/lib/sdk/crt/crt.cmake
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/lib/sdk/crt/crt.cmake?rev=6...
==============================================================================
--- trunk/reactos/lib/sdk/crt/crt.cmake	[iso-8859-1] (original)
+++ trunk/reactos/lib/sdk/crt/crt.cmake	[iso-8859-1] Sun Apr 12 17:08:11 2015
@@ -475,6 +475,9 @@
             except/amd64/cpp.s)
     endif()
 elseif(ARCH STREQUAL "arm")
+    list(APPEND LIBCNTPR_SOURCE
+        math/arm/__rt_udiv.c
+    )
     list(APPEND CRT_ASM_SOURCE
         math/arm/floor.s
         math/arm/log10.s
@@ -483,7 +486,6 @@
         math/arm/__u64tod.s
         math/arm/__rt_sdiv.s
         math/arm/__rt_sdiv64.s
-        math/arm/__rt_udiv.s
         math/arm/__rt_udiv64.s
     )
 endif()

Modified: trunk/reactos/lib/sdk/crt/libcntpr.cmake
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/lib/sdk/crt/libcntpr.cmake?...
==============================================================================
--- trunk/reactos/lib/sdk/crt/libcntpr.cmake	[iso-8859-1] (original)
+++ trunk/reactos/lib/sdk/crt/libcntpr.cmake	[iso-8859-1] Sun Apr 12 17:08:11 2015
@@ -134,6 +134,9 @@
         math/cos.c
         math/sin.c)
 elseif(ARCH STREQUAL "arm")
+    list(APPEND LIBCNTPR_SOURCE
+        math/arm/__rt_udiv.c
+    )
     list(APPEND LIBCNTPR_ASM_SOURCE
         math/arm/floor.s
         math/arm/log10.s
@@ -142,7 +145,6 @@
         math/arm/__u64tod.s
         math/arm/__rt_sdiv.s
         math/arm/__rt_sdiv64.s
-        math/arm/__rt_udiv.s
         math/arm/__rt_udiv64.s
     )
 endif()

Added: trunk/reactos/lib/sdk/crt/math/arm/__rt_udiv.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/lib/sdk/crt/math/arm/__rt_u...
==============================================================================
--- trunk/reactos/lib/sdk/crt/math/arm/__rt_udiv.c	(added)
+++ trunk/reactos/lib/sdk/crt/math/arm/__rt_udiv.c	[iso-8859-1] Sun Apr 12 17:08:11 2015
@@ -0,0 +1,73 @@
+/*
+ * COPYRIGHT:       BSD, see COPYING.ARM in the top level directory
+ * PROJECT:         ReactOS crt library
+ * FILE:            lib/sdk/crt/math/arm/__rt_udiv.c
+ * PURPOSE:         Implementation of __rt_udiv
+ * PROGRAMMER:      Timo Kreuzer
+ * REFERENCE:       http://research.microsoft.com/en-us/um/redmond/projects/invisible/src/crt/md...
+ *                  http://research.microsoft.com/en-us/um/redmond/projects/invisible/src/crt/md...
+ */
+
+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);
+}
+
+ARM_UDIVRESULT
+__rt_udiv(
+    unsigned int divisor,
+    unsigned int dividend)
+{
+    ARM_UDIVRESULT result;
+    unsigned int BitShift;
+    unsigned int BitMask;
+    unsigned int Quotient;
+
+    if (divisor == 0)
+    {
+        /* Raise divide by zero error */
+        __brkdiv0();
+    }
+
+    if (divisor > dividend)
+    {
+        result.quotient = 0;
+        result.modulus = divisor;
+        return result;
+    }
+
+    /* Get the difference in count of leading zeros between dividend and divisor */
+    BitShift = _CountLeadingZeros(divisor);
+    BitShift -= _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 <<= BitShift;
+
+    BitMask = 1 << BitShift;
+
+    do
+    {
+        if (dividend >= divisor)
+        {
+            Quotient |= BitMask;
+            dividend -= divisor;
+        }
+        divisor >>= 1;
+        BitMask >>= 1;
+    }
+    while (BitMask);
+
+    result.quotient = Quotient;
+    result.modulus = dividend;
+    return result;
+}
+

Propchange: trunk/reactos/lib/sdk/crt/math/arm/__rt_udiv.c
------------------------------------------------------------------------------
    svn:eol-style = native

Removed: trunk/reactos/lib/sdk/crt/math/arm/__rt_udiv.s
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/lib/sdk/crt/math/arm/__rt_u...
==============================================================================
--- trunk/reactos/lib/sdk/crt/math/arm/__rt_udiv.s	[iso-8859-1] (original)
+++ trunk/reactos/lib/sdk/crt/math/arm/__rt_udiv.s	(removed)
@@ -1,20 +0,0 @@
-/*
- * COPYRIGHT:         See COPYING in the top level directory
- * PROJECT:           ReactOS system libraries
- * PURPOSE:           Implementation of __rt_udiv
- * PROGRAMMER:        Timo Kreuzer ([e-mail])
- */
-
-/* INCLUDES ******************************************************************/
-
-#include <kxarm.h>
-
-/* CODE **********************************************************************/
-    TEXTAREA
-
-    LEAF_ENTRY __rt_udiv
-
-    LEAF_END __rt_udiv
-
-    END
-/* EOF */