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[CRT]

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Implement __rt_udiv in C.

svn path=/trunk/; revision=67178
This commit is contained in:
Timo Kreuzer 2015-04-12 17:08:11 +00:00
parent fe19391da7
commit 59f40e274f
4 changed files with 79 additions and 22 deletions
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4
reactos/lib/sdk/crt/crt.cmake
View file

@ -475,6 +475,9 @@ elseif(ARCH STREQUAL "amd64")
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 @@ elseif(ARCH STREQUAL "arm")
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()

4
reactos/lib/sdk/crt/libcntpr.cmake
View file

@ -134,6 +134,9 @@ elseif(ARCH STREQUAL "amd64")
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 @@ elseif(ARCH STREQUAL "arm")
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()

73
reactos/lib/sdk/crt/math/arm/__rt_udiv.c Normal file
View file

@ -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/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);
}
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;
}

20
reactos/lib/sdk/crt/math/arm/__rt_udiv.s
View file

@ -1,20 +0,0 @@
/*
* COPYRIGHT: See COPYING in the top level directory
* PROJECT: ReactOS system libraries
* PURPOSE: Implementation of __rt_udiv
* PROGRAMMER: Timo Kreuzer (timo.kreuzer@reactos.org)
*/
/* INCLUDES ******************************************************************/
#include <kxarm.h>
/* CODE **********************************************************************/
TEXTAREA
LEAF_ENTRY __rt_udiv
LEAF_END __rt_udiv
END
/* EOF */