[tkreuzer] 67179: [CRT] Implement __rt_sdiv as a wrapper around the unsigned divide (now factored out into an inline worker function)

Author: tkreuzer
Date: Sun Apr 12 18:07:19 2015
New Revision: 67179

URL: http://svn.reactos.org/svn/reactos?rev=67179&view=rev
Log:
[CRT]
Implement __rt_sdiv as a wrapper around the unsigned divide (now factored out into an
inline worker function)

Added:
    trunk/reactos/lib/sdk/crt/math/arm/__rt_div.c
      - copied, changed from r67178, trunk/reactos/lib/sdk/crt/math/arm/__rt_udiv.c
Removed:
    trunk/reactos/lib/sdk/crt/math/arm/__rt_sdiv.s
    trunk/reactos/lib/sdk/crt/math/arm/__rt_udiv.c
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=…
==============================================================================
--- trunk/reactos/lib/sdk/crt/crt.cmake	[iso-8859-1] (original)
+++ trunk/reactos/lib/sdk/crt/crt.cmake	[iso-8859-1] Sun Apr 12 18:07:19 2015
@@ -476,7 +476,7 @@
     endif()
 elseif(ARCH STREQUAL "arm")
     list(APPEND LIBCNTPR_SOURCE
-        math/arm/__rt_udiv.c
+        math/arm/__rt_div.c
     )
     list(APPEND CRT_ASM_SOURCE
         math/arm/floor.s
@@ -484,7 +484,6 @@
         math/arm/pow.s
         math/arm/__dtou64.s
         math/arm/__u64tod.s
-        math/arm/__rt_sdiv.s
         math/arm/__rt_sdiv64.s
         math/arm/__rt_udiv64.s
     )

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 18:07:19 2015
@@ -135,7 +135,7 @@
         math/sin.c)
 elseif(ARCH STREQUAL "arm")
     list(APPEND LIBCNTPR_SOURCE
-        math/arm/__rt_udiv.c
+        math/arm/__rt_div.c
     )
     list(APPEND LIBCNTPR_ASM_SOURCE
         math/arm/floor.s
@@ -143,7 +143,6 @@
         math/arm/pow.s
         math/arm/__dtou64.s
         math/arm/__u64tod.s
-        math/arm/__rt_sdiv.s
         math/arm/__rt_sdiv64.s
         math/arm/__rt_udiv64.s
     )

Copied: trunk/reactos/lib/sdk/crt/math/arm/__rt_div.c (from r67178,
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_…
==============================================================================
--- trunk/reactos/lib/sdk/crt/math/arm/__rt_udiv.c	[iso-8859-1] (original)
+++ trunk/reactos/lib/sdk/crt/math/arm/__rt_div.c	[iso-8859-1] Sun Apr 12 18:07:19 2015
@@ -21,15 +21,16 @@
     __emit(0xDEF9);
 }
 
-ARM_UDIVRESULT
-__rt_udiv(
+__forceinline
+void
+__rt_udiv_internal(
+    ARM_UDIVRESULT *result,
     unsigned int divisor,
     unsigned int dividend)
 {
-    ARM_UDIVRESULT result;
-    unsigned int BitShift;
-    unsigned int BitMask;
-    unsigned int Quotient;
+    unsigned int shift;
+    unsigned int mask;
+    unsigned int quotient;
 
     if (divisor == 0)
     {
@@ -39,35 +40,87 @@
 
     if (divisor > dividend)
     {
-        result.quotient = 0;
-        result.modulus = divisor;
-        return result;
+        result->quotient = 0;
+        result->modulus = divisor;
+        return;
     }
 
     /* Get the difference in count of leading zeros between dividend and divisor */
-    BitShift = _CountLeadingZeros(divisor);
-    BitShift -= _CountLeadingZeros(dividend);
+    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 <<= BitShift;
+    divisor <<= shift;
 
-    BitMask = 1 << BitShift;
+    mask = 1 << shift;
 
+    quotient = 0;
     do
     {
         if (dividend >= divisor)
         {
-            Quotient |= BitMask;
+            quotient |= mask;
             dividend -= divisor;
         }
         divisor >>= 1;
-        BitMask >>= 1;
+        mask >>= 1;
     }
-    while (BitMask);
+    while (mask);
 
-    result.quotient = Quotient;
-    result.modulus = dividend;
+    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;
+}

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

Removed: 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_…
==============================================================================
--- trunk/reactos/lib/sdk/crt/math/arm/__rt_udiv.c	[iso-8859-1] (original)
+++ trunk/reactos/lib/sdk/crt/math/arm/__rt_udiv.c	(removed)
@@ -1,73 +0,0 @@
-/*
- * 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/m…
- *                 
http://research.microsoft.com/en-us/um/redmond/projects/invisible/src/crt/m…
- */
-
-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;
-}
-