[CRT]

Refactor the code for __rt_div to allow reusing it for __rt_sdiv64 and __rt_udiv64 and implement those as asm wrappers around worker functions (due to the calling convention they cannot be implemented fully in C)

svn path=/trunk/; revision=67195

reactos/lib/sdk/crt/crt.cmake

@@ -476,7 +476,10 @@ elseif(ARCH STREQUAL "amd64")
     endif()
 elseif(ARCH STREQUAL "arm")
     list(APPEND LIBCNTPR_SOURCE
-        math/arm/__rt_div.c
+        math/arm/__rt_sdiv.c
+        math/arm/__rt_sdiv64_worker.c
+        math/arm/__rt_udiv.c
+        math/arm/__rt_udiv64_worker.c
     )
     list(APPEND CRT_ASM_SOURCE
         math/arm/floor.s

reactos/lib/sdk/crt/libcntpr.cmake

@@ -135,7 +135,10 @@ elseif(ARCH STREQUAL "amd64")
         math/sin.c)
 elseif(ARCH STREQUAL "arm")
     list(APPEND LIBCNTPR_SOURCE
-        math/arm/__rt_div.c
+        math/arm/__rt_sdiv.c
+        math/arm/__rt_sdiv64_worker.c
+        math/arm/__rt_udiv.c
+        math/arm/__rt_udiv64_worker.c
     )
     list(APPEND LIBCNTPR_ASM_SOURCE
         math/arm/floor.s

reactos/lib/sdk/crt/math/arm/__rt_div_worker.h

@@ -0,0 +1,116 @@
+/*
+ * 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/pubs/70645/tr-2008-141.pdf
+ *                  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
+ */
+
+#ifdef _USE_64_BITS_
+typedef unsigned long long UINT3264;
+typedef long long INT3264;
+#define _CountLeadingZeros _CountLeadingZeros64
+#else
+typedef unsigned int UINT3264;
+typedef int INT3264;
+#endif
+
+__forceinline
+void
+__brkdiv0(void)
+{
+    __emit(0xDEF9);
+}
+
+typedef struct _ARM_DIVRESULT
+{
+    UINT3264 quotient; /* to be returned in R0 */
+    UINT3264 modulus;  /* to be returned in R1 */
+} ARM_DIVRESULT;
+
+#ifndef _USE_64_BITS_
+__forceinline
+#endif
+void
+__rt_div_worker(
+    ARM_DIVRESULT *result,
+    UINT3264 divisor,
+    UINT3264 dividend)
+{
+    UINT3264 shift;
+    UINT3264 mask;
+    UINT3264 quotient;
+#ifdef _SIGNED_DIV_
+    int dividend_sign;
+    int divisor_sign;
+#endif // _SIGNED_DIV_
+
+    if (divisor == 0)
+    {
+        /* Raise divide by zero error */
+        __brkdiv0();
+    }
+
+#ifdef _SIGNED_DIV_
+    if ((INT3264)dividend < 0)
+    {
+        dividend_sign = 1;
+        dividend = -(INT3264)dividend;
+    }
+
+    if ((INT3264)divisor < 0)
+    {
+        divisor_sign = 1;
+        divisor = -(INT3264)divisor;
+    }
+#endif // _SIGNED_DIV_
+
+    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 = (UINT3264)1 << shift;
+
+    quotient = 0;
+    do
+    {
+        if (dividend >= divisor)
+        {
+            quotient |= mask;
+            dividend -= divisor;
+        }
+        divisor >>= 1;
+        mask >>= 1;
+    }
+    while (mask);
+
+#ifdef _SIGNED_DIV_
+    if (dividend_sign ^ divisor_sign)
+    {
+        quotient = -(INT3264)quotient;
+    }
+
+    if (dividend_sign)
+    {
+        dividend = -(INT3264)dividend;
+    }
+#endif // _SIGNED_DIV_
+
+    result->quotient = quotient;
+    result->modulus = dividend;
+    return;
+}

reactos/lib/sdk/crt/math/arm/__rt_sdiv.c

@@ -0,0 +1,26 @@
+/*
+ * COPYRIGHT:       BSD, see COPYING.ARM in the top level directory
+ * PROJECT:         ReactOS crt library
+ * FILE:            lib/sdk/crt/math/arm/__rt_sdiv.c
+ * PURPOSE:         Implementation of __rt_sdiv
+ * 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
+ */
+
+#define __rt_div_worker __rt_sdiv_worker
+#define _SIGNED_DIV_
+
+#include "__rt_div_worker.h"
+
+ARM_DIVRESULT
+__rt_sdiv(
+    int divisor,
+    int dividend)
+{
+    ARM_DIVRESULT result;
+
+    __rt_sdiv_worker(&result, divisor, dividend);
+    return result;
+}
+

reactos/lib/sdk/crt/math/arm/__rt_sdiv64.s

@@ -9,12 +9,28 @@
 
 #include <kxarm.h>
 
+    IMPORT __rt_sdiv64_worker
+
 /* CODE **********************************************************************/
     TEXTAREA
 
-    LEAF_ENTRY __rt_sdiv64
+    NESTED_ENTRY __rt_sdiv64
 
-    LEAF_END __rt_sdiv64
+    /* Allocate stack space and store parameters there */
+    stmdb sp!,{r0,r1,r2,r3,lr}
+    PROLOG_END
+
+    /* Load pointer to stack structure into R0 */
+    mov r0, sp
+
+    /* Call the C worker function */
+    adr lr, Return
+    b __rt_sdiv64_worker
+
+Return
+    /* Move result data into the appropriate registers and return */
+    ldmia sp!,{r0,r1,r2,r3,pc}
+    ENTRY_END __rt_sdiv64
 
     END
 /* EOF */

reactos/lib/sdk/crt/math/arm/__rt_sdiv64_worker.c

@@ -0,0 +1,17 @@
+/*
+ * COPYRIGHT:       BSD, see COPYING.ARM in the top level directory
+ * PROJECT:         ReactOS crt library
+ * FILE:            lib/sdk/crt/math/arm/__rt_sdiv_worker.c
+ * PURPOSE:         Implementation of __rt_sdiv_worker
+ * 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
+ */
+
+#define __rt_div_worker __rt_sdiv64_worker
+#define _SIGNED_DIV_
+#define _USE_64_BITS_
+
+#include "__rt_div_worker.h"
+
+/* __rt_sdiv64 is implemented in __rt_sdiv64.s */

reactos/lib/sdk/crt/math/arm/__rt_udiv.c

@@ -0,0 +1,25 @@
+/*
+ * 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/arm/_div10.s.htm
+ *                  http://research.microsoft.com/en-us/um/redmond/projects/invisible/src/crt/md/arm/_udiv.c.htm
+ */
+
+#define __rt_div_worker __rt_udiv_worker
+
+#include "__rt_div_worker.h"
+
+ARM_DIVRESULT
+__rt_udiv(
+    unsigned int divisor,
+    unsigned int dividend)
+{
+    ARM_DIVRESULT result;
+
+    __rt_udiv_worker(&result, divisor, dividend);
+    return result;
+}
+

reactos/lib/sdk/crt/math/arm/__rt_udiv64.s

@@ -9,12 +9,28 @@
 
 #include <kxarm.h>
 
+    IMPORT __rt_udiv64_worker
+
 /* CODE **********************************************************************/
     TEXTAREA
 
-    LEAF_ENTRY __rt_udiv64
+    NESTED_ENTRY __rt_udiv64
 
-    LEAF_END __rt_udiv64
+    /* Allocate stack space and store parameters there */
+    stmdb sp!,{r0,r1,r2,r3,lr}
+    PROLOG_END
+
+    /* Load pointer to stack structure into R0 */
+    mov r0, sp
+
+    /* Call the C worker function */
+    adr lr, Return
+    b __rt_udiv64_worker
+
+Return
+    /* Move result data into the appropriate registers and return */
+    ldmia sp!,{r0,r1,r2,r3,pc}
+    ENTRY_END __rt_udiv64
 
     END
 /* EOF */

reactos/lib/sdk/crt/math/arm/__rt_udiv64_worker.c

@@ -0,0 +1,16 @@
+/*
+ * COPYRIGHT:       BSD, see COPYING.ARM in the top level directory
+ * PROJECT:         ReactOS crt library
+ * FILE:            lib/sdk/crt/math/arm/__rt_udiv64_worker.c
+ * PURPOSE:         Implementation of __rt_udiv64_worker
+ * 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
+ */
+
+#define __rt_div_worker __rt_udiv64_worker
+#define _USE_64_BITS_
+
+#include "__rt_div_worker.h"
+
+/* __rt_udiv64 is implemented in __rt_udiv64.s */