tomasz.sowa
/
ttmath
1
0
Fork 0
Code Issues Pull Requests Releases Activity
ttmath/ttmath/ttmathuint_x86_64.h

1085 lines
24 KiB
C++
Raw Blame History

/*
* This file is a part of TTMath Bignum Library
* and is distributed under the (new) BSD licence.
* Author: Tomasz Sowa <t.sowa@ttmath.org>
*/
/*
* Copyright (c) 2006-2009, Tomasz Sowa
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name Tomasz Sowa nor the names of contributors to this
* project may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef headerfilettmathuint_x86_64
#define headerfilettmathuint_x86_64
#ifndef TTMATH_NOASM
#ifdef TTMATH_PLATFORM64
#pragma message("TTMATH_ASM64")
/*!
\file ttmathuint_x86_64.h
\brief template class UInt<uint> with assembler code for 64bit x86_64 processors
this file is included at the end of ttmathuint.h
*/
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
namespace ttmath
{
#if defined(_M_X64)
#include <intrin.h>
extern "C"
{
uint __fastcall adc_x64(uint* p1, const uint* p2, uint nSize, uint c);
uint __fastcall addindexed_x64(uint* p1, uint nSize, uint nPos, uint nValue);
uint __fastcall addindexed2_x64(uint* p1, uint nSize, uint nPos, uint nValue1, uint nValue2);
uint __fastcall sbb_x64(uint* p1, const uint* p2, uint nSize, uint c);
uint __fastcall subindexed_x64(uint* p1, uint nSize, uint nPos, uint nValue);
uint __fastcall rcl_x64(uint* p1, uint nSize, uint nLowestBit);
uint __fastcall rcr_x64(uint* p1, uint nSize, uint nLowestBit);
uint __fastcall div_x64(uint* pnValHi, uint* pnValLo, uint nDiv);
uint __fastcall rcl2_x64(uint* p1, uint nSize, uint nBits, uint c);
uint __fastcall rcr2_x64(uint* p1, uint nSize, uint nBits, uint c);
};
#endif
/*!
*
* basic mathematic functions
*
*/
/*!
this method adding ss2 to the this and adding carry if it's defined
(this = this + ss2 + c)
***this method is created only on a 64bit platform***
c must be zero or one (might be a bigger value than 1)
function returns carry (1) (if it was)
*/
template<uint value_size>
uint UInt<value_size>::Add(const UInt<value_size> & ss2, uint c)
{
uint b = value_size;
uint * p1 = table;
const uint * p2 = ss2.table;
// we don't have to use TTMATH_REFERENCE_ASSERT here
// this algorithm doesn't require it
#ifndef __GNUC__
#if defined(_M_X64)
c = adc_x64(p1,p2,b,c);
#else
#error "another compiler than GCC is currently not supported in 64bit mode"
#endif
#endif
#ifdef __GNUC__
uint dummy, dummy2;
/*
this part should be compiled with gcc
*/
__asm__ __volatile__(
"xorq %%rdx, %%rdx \n"
"negq %%rax \n" // CF=1 if rax!=0 , CF=0 if rax==0
"1: \n"
"movq (%%rsi,%%rdx,8), %%rax \n"
"adcq %%rax, (%%rbx,%%rdx,8) \n"
"incq %%rdx \n"
"decq %%rcx \n"
"jnz 1b \n"
"adcq %%rcx, %%rcx \n"
: "=c" (c), "=a" (dummy), "=d" (dummy2)
: "0" (b), "1" (c), "b" (p1), "S" (p2)
: "cc", "memory" );
#endif
TTMATH_LOG("UInt::Add")
return c;
}
/*!
this method adds one word (at a specific position)
and returns a carry (if it was)
***this method is created only on a 64bit platform***
if we've got (value_size=3):
table[0] = 10;
table[1] = 30;
table[2] = 5;
and we call:
AddInt(2,1)
then it'll be:
table[0] = 10;
table[1] = 30 + 2;
table[2] = 5;
of course if there was a carry from table[2] it would be returned
*/
template<uint value_size>
uint UInt<value_size>::AddInt(uint value, uint index)
{
uint b = value_size;
uint * p1 = table;
uint c;
TTMATH_ASSERT( index < value_size )
#ifndef __GNUC__
#if defined(_M_X64)
c = addindexed_x64(p1,b,index,value);
#else
#error "another compiler than GCC is currently not supported in 64bit mode"
#endif
#endif
#ifdef __GNUC__
uint dummy, dummy2;
__asm__ __volatile__(
"subq %%rdx, %%rcx \n"
"1: \n"
"addq %%rax, (%%rbx,%%rdx,8) \n"
"jnc 2f \n"
"movq $1, %%rax \n"
"incq %%rdx \n"
"decq %%rcx \n"
"jnz 1b \n"
"2: \n"
"setc %%al \n"
"movzx %%al, %%rdx \n"
: "=d" (c), "=a" (dummy), "=c" (dummy2)
: "0" (index), "1" (value), "2" (b), "b" (p1)
: "cc", "memory" );
#endif
TTMATH_LOG("UInt::AddInt")
return c;
}
/*!
this method adds only two unsigned words to the existing value
and these words begin on the 'index' position
(it's used in the multiplication algorithm 2)
***this method is created only on a 64bit platform***
index should be equal or smaller than value_size-2 (index <= value_size-2)
x1 - lower word, x2 - higher word
for example if we've got value_size equal 4 and:
table[0] = 3
table[1] = 4
table[2] = 5
table[3] = 6
then let
x1 = 10
x2 = 20
and
index = 1
the result of this method will be:
table[0] = 3
table[1] = 4 + x1 = 14
table[2] = 5 + x2 = 25
table[3] = 6
and no carry at the end of table[3]
(of course if there was a carry in table[2](5+20) then
this carry would be passed to the table[3] etc.)
*/
template<uint value_size>
uint UInt<value_size>::AddTwoInts(uint x2, uint x1, uint index)
#if 0
{
uint i, c;
TTMATH_ASSERT( index < value_size )
printf("add %Id + %Id\n",x1,x2);
for(int i=index ; i<value_size ; ++i)
printf("%d: %Id\n",i,table[i]);
c = AddTwoWords(table[index], x1, 0, &table[index]);
c = AddTwoWords(table[index+1], x2, c, &table[index+1]);
for(i=index+2 ; i<value_size && c ; ++i)
c = AddTwoWords(table[i], 0, c, &table[i]);
for(i=index ; i<value_size ; ++i)
printf("%d: %Id\n",i,table[i]);
printf(" -> %d\n",c);
TTMATH_LOG("UInt::AddTwoInts")
return c;
}
#else
{
uint b = value_size;
uint * p1 = table;
uint c;
TTMATH_ASSERT( index < value_size - 1 )
#ifndef __GNUC__
#if defined(_M_X64)
//printf("add %Id + %Id\n",x1,x2);
//for(int i=index ; i<value_size ; ++i)
// printf("%d: %Id\n",i,table[i]);
//if (table[0] == 1265784741359897913) DebugBreak();
c = addindexed2_x64(p1,b,index,x1,x2);
//for(int i=index ; i<value_size ; ++i)
// printf("%d: %Id\n",i,table[i]);
//printf(" -> %d\n",c);
#else
#error "another compiler than GCC is currently not supported in 64bit mode"
#endif
#endif
#ifdef __GNUC__
uint dummy, dummy2;
__asm__ __volatile__(
"subq %%rdx, %%rcx \n"
"addq %%rsi, (%%rbx,%%rdx,8) \n"
"incq %%rdx \n"
"decq %%rcx \n"
"1: \n"
"adcq %%rax, (%%rbx,%%rdx,8) \n"
"jnc 2f \n"
"mov $0, %%rax \n"
"incq %%rdx \n"
"decq %%rcx \n"
"jnz 1b \n"
"2: \n"
"setc %%al \n"
"movzx %%al, %%rax \n"
: "=a" (c), "=c" (dummy), "=d" (dummy2)
: "0" (x2), "1" (b), "2" (index), "b" (p1), "S" (x1)
: "cc", "memory" );
#endif
TTMATH_LOG("UInt::AddTwoInts")
return c;
}
#endif
/*!
this method's subtracting ss2 from the 'this' and subtracting
carry if it has been defined
(this = this - ss2 - c)
***this method is created only on a 64bit platform***
c must be zero or one (might be a bigger value than 1)
function returns carry (1) (if it was)
*/
template<uint value_size>
uint UInt<value_size>::Sub(const UInt<value_size> & ss2, uint c)
{
uint b = value_size;
uint * p1 = table;
const uint * p2 = ss2.table;
// we don't have to use TTMATH_REFERENCE_ASSERT here
// this algorithm doesn't require it
#ifndef __GNUC__
#if defined(_M_X64)
c = sbb_x64(p1,p2,b,c);
#else
#error "another compiler than GCC is currently not supported in 64bit mode"
#endif
#endif
#ifdef __GNUC__
uint dummy, dummy2;
__asm__ __volatile__(
"xorq %%rdx, %%rdx \n"
"negq %%rax \n" // CF=1 if rax!=0 , CF=0 if rax==0
"1: \n"
"movq (%%rsi,%%rdx,8), %%rax \n"
"sbbq %%rax, (%%rbx,%%rdx,8) \n"
"incq %%rdx \n"
"decq %%rcx \n"
"jnz 1b \n"
"adcq %%rcx, %%rcx \n"
: "=c" (c), "=a" (dummy), "=d" (dummy2)
: "0" (b), "1" (c), "b" (p1), "S" (p2)
: "cc", "memory" );
#endif
TTMATH_LOG("UInt::Sub")
return c;
}
/*!
this method subtracts one word (at a specific position)
and returns a carry (if it was)
***this method is created only on a 64bit platform***
if we've got (value_size=3):
table[0] = 10;
table[1] = 30;
table[2] = 5;
and we call:
SubInt(2,1)
then it'll be:
table[0] = 10;
table[1] = 30 - 2;
table[2] = 5;
of course if there was a carry from table[2] it would be returned
*/
template<uint value_size>
uint UInt<value_size>::SubInt(uint value, uint index)
{
uint b = value_size;
uint * p1 = table;
uint c;
TTMATH_ASSERT( index < value_size )
#ifndef __GNUC__
#if defined(_M_X64)
c = subindexed_x64(p1,b,index,value);
#else
#error "another compiler than GCC is currently not supported in 64bit mode"
#endif
#endif
#ifdef __GNUC__
uint dummy, dummy2;
__asm__ __volatile__(
"subq %%rdx, %%rcx \n"
"1: \n"
"subq %%rax, (%%rbx,%%rdx,8) \n"
"jnc 2f \n"
"movq $1, %%rax \n"
"incq %%rdx \n"
"decq %%rcx \n"
"jnz 1b \n"
"2: \n"
"setc %%al \n"
"movzx %%al, %%rdx \n"
: "=d" (c), "=a" (dummy), "=c" (dummy2)
: "0" (index), "1" (value), "2" (b), "b" (p1)
: "cc", "memory" );
#endif
TTMATH_LOG("UInt64::SubInt")
return c;
}
/*!
this method moves all bits into the left hand side
return value <- this <- c
the lowest *bit* will be held the 'c' and
the state of one additional bit (on the left hand side)
will be returned
for example:
let this is 001010000
after Rcl2_one(1) there'll be 010100001 and Rcl2_one returns 0
***this method is created only on a 64bit platform***
*/
template<uint value_size>
uint UInt<value_size>::Rcl2_one(uint c)
{
sint b = value_size;
uint * p1 = table;
#ifndef __GNUC__
#if defined(_M_X64)
c = rcl_x64(p1,b,c);
#else
#error "another compiler than GCC is currently not supported in 64bit mode"
#endif
#endif
#ifdef __GNUC__
uint dummy, dummy2;
__asm__ __volatile__(
"xorq %%rdx, %%rdx \n" // rdx=0
"negq %%rax \n" // CF=1 if rax!=0 , CF=0 if rax==0
"1: \n"
"rclq $1, (%%rbx, %%rdx, 8) \n"
"incq %%rdx \n"
"decq %%rcx \n"
"jnz 1b \n"
"adcq %%rcx, %%rcx \n"
: "=c" (c), "=a" (dummy), "=d" (dummy2)
: "0" (b), "1" (c), "b" (p1)
: "cc", "memory" );
#endif
TTMATH_LOG("UInt::Rcl2_one")
return c;
}
/*!
this method moves all bits into the right hand side
c -> this -> return value
the highest *bit* will be held the 'c' and
the state of one additional bit (on the right hand side)
will be returned
for example:
let this is 000000010
after Rcr2_one(1) there'll be 100000001 and Rcr2_one returns 0
***this method is created only on a 64bit platform***
*/
template<uint value_size>
uint UInt<value_size>::Rcr2_one(uint c)
{
sint b = value_size;
uint * p1 = table;
#ifndef __GNUC__
#if defined(_M_X64)
c = rcr_x64(p1,b,c);
#else
#error "another compiler than GCC is currently not supported in 64bit mode"
#endif
#endif
#ifdef __GNUC__
uint dummy;
__asm__ __volatile__(
"negq %%rax \n" // CF=1 if rax!=0 , CF=0 if rax==0
"1: \n"
"rcrq $1, -8(%%rbx, %%rcx, 8) \n"
"decq %%rcx \n"
"jnz 1b \n"
"adcq %%rcx, %%rcx \n"
: "=c" (c), "=a" (dummy)
: "0" (b), "1" (c), "b" (p1)
: "cc", "memory" );
#endif
TTMATH_LOG("UInt::Rcr2_one")
return c;
}
/*!
this method moves all bits into the left hand side
return value <- this <- c
the lowest *bits* will be held the 'c' and
the state of one additional bit (on the left hand side)
will be returned
for example:
let this is 001010000
after Rcl2(3, 1) there'll be 010000111 and Rcl2 returns 1
***this method is created only on a 64bit platform***
*/
template<uint value_size>
uint UInt<value_size>::Rcl2(uint bits, uint c)
{
TTMATH_ASSERT( bits>0 && bits<TTMATH_BITS_PER_UINT )
uint b = value_size;
uint * p1 = table;
#ifndef __GNUC__
#if defined(_M_X64)
c = rcl2_x64(p1,b,bits,c);
#else
#error "another compiler than GCC is currently not supported in 64bit mode"
#endif
#endif
#ifdef __GNUC__
uint dummy, dummy2, dummy3;
__asm__ __volatile__(
"movq %%rcx, %%rsi \n"
"movq $64, %%rcx \n"
"subq %%rsi, %%rcx \n"
"movq $-1, %%rdx \n"
"shrq %%cl, %%rdx \n"
"movq %%rdx, %%r8 \n"
"movq %%rsi, %%rcx \n"
"xorq %%rdx, %%rdx \n"
"movq %%rdx, %%rsi \n"
"orq %%rax, %%rax \n"
"cmovnz %%r8, %%rsi \n"
"1: \n"
"rolq %%cl, (%%rbx,%%rdx,8) \n"
"movq (%%rbx,%%rdx,8), %%rax \n"
"andq %%r8, %%rax \n"
"xorq %%rax, (%%rbx,%%rdx,8) \n"
"orq %%rsi, (%%rbx,%%rdx,8) \n"
"movq %%rax, %%rsi \n"
"incq %%rdx \n"
"decq %%rdi \n"
"jnz 1b \n"
"and $1, %%rax \n"
: "=a" (c), "=D" (dummy), "=S" (dummy2), "=d" (dummy3)
: "0" (c), "1" (b), "b" (p1), "c" (bits)
: "%r8", "cc", "memory" );
#endif
TTMATH_LOG("UInt::Rcl2")
return c;
}
/*!
this method moves all bits into the right hand side
C -> this -> return value
the highest *bits* will be held the 'c' and
the state of one additional bit (on the right hand side)
will be returned
for example:
let this is 000000010
after Rcr2(2, 1) there'll be 110000000 and Rcr2 returns 1
***this method is created only on a 64bit platform***
*/
template<uint value_size>
uint UInt<value_size>::Rcr2(uint bits, uint c)
{
TTMATH_ASSERT( bits>0 && bits<TTMATH_BITS_PER_UINT )
sint b = value_size;
uint * p1 = table;
#ifndef __GNUC__
#if defined(_M_X64)
c = rcr2_x64(p1,b,bits,c);
#else
#error "another compiler than GCC is currently not supported in 64bit mode"
#endif
#endif
#ifdef __GNUC__
uint dummy, dummy2, dummy3;
__asm__ __volatile__(
"movq %%rcx, %%rsi \n"
"movq $64, %%rcx \n"
"subq %%rsi, %%rcx \n"
"movq $-1, %%rdx \n"
"shlq %%cl, %%rdx \n"
"movq %%rdx, %%R8 \n"
"movq %%rsi, %%rcx \n"
"xorq %%rdx, %%rdx \n"
"movq %%rdx, %%rsi \n"
"addq %%rdi, %%rdx \n"
"decq %%rdx \n"
"orq %%rax, %%rax \n"
"cmovnz %%R8, %%rsi \n"
"1: \n"
"rorq %%cl, (%%rbx,%%rdx,8) \n"
"movq (%%rbx,%%rdx,8), %%rax \n"
"andq %%R8, %%rax \n"
"xorq %%rax, (%%rbx,%%rdx,8) \n"
"orq %%rsi, (%%rbx,%%rdx,8) \n"
"movq %%rax, %%rsi \n"
"decq %%rdx \n"
"decq %%rdi \n"
"jnz 1b \n"
"rolq $1, %%rax \n"
"andq $1, %%rax \n"
: "=a" (c), "=D" (dummy), "=S" (dummy2), "=d" (dummy3)
: "0" (c), "1" (b), "b" (p1), "c" (bits)
: "%r8", "cc", "memory" );
#endif
TTMATH_LOG("UInt::Rcr2")
return c;
}
/*
this method returns the number of the highest set bit in one 64-bit word
if the 'x' is zero this method returns '-1'
***this method is created only on a 64bit platform***
*/
template<uint value_size>
sint UInt<value_size>::FindLeadingBitInWord(uint x)
{
register sint result;
#ifndef __GNUC__
#if defined(_MSC_VER)
unsigned long nIndex(0);
if (_BitScanReverse64(&nIndex,x) == 0)
result = -1;
else
result = nIndex;
#else
#error "another compiler than GCC is currently not supported in 64bit mode"
#endif
#endif
#ifdef __GNUC__
uint dummy;
__asm__ (
"movq $-1, %1 \n"
"bsrq %2, %0 \n"
"cmovz %1, %0 \n"
: "=r" (result), "=&r" (dummy)
: "r" (x)
: "cc" );
#endif
return result;
}
/*!
this method sets a special bit in the 'value'
and returns the last state of the bit (zero or one)
***this method is created only on a 64bit platform***
bit is from <0,63>
e.g.
uint x = 100;
uint bit = SetBitInWord(x, 3);
now: x = 108 and bit = 0
*/
template<uint value_size>
uint UInt<value_size>::SetBitInWord(uint & value, uint bit)
{
TTMATH_ASSERT( bit < TTMATH_BITS_PER_UINT )
uint old_bit;
uint v = value;
#ifndef __GNUC__
#if defined(_MSC_VER)
#if defined(TTMATH_PLATFORM64)
old_bit = _bittestandset64((__int64*)&value,bit) != 0;
#else
old_bit = _bittestandset((long*)&value,bit) != 0;
#endif
#else
#error "another compiler than GCC is currently not supported in 64bit mode"
#endif
#endif
#ifdef __GNUC__
__asm__ (
"btsq %%rbx, %%rax \n"
"setc %%bl \n"
"movzx %%bl, %%rbx \n"
: "=a" (v), "=b" (old_bit)
: "0" (v), "1" (bit)
: "cc" );
#endif
value = v;
return old_bit;
}
/*!
*
* Multiplication
*
*
*/
/*!
multiplication: result_high:result_low = a * b
result_high - higher word of the result
result_low - lower word of the result
this methos never returns a carry
this method is used in the second version of the multiplication algorithms
***this method is created only on a 64bit platform***
*/
template<uint value_size>
void UInt<value_size>::MulTwoWords(uint a, uint b, uint * result_high, uint * result_low)
{
/*
we must use these temporary variables in order to inform the compilator
that value pointed with result1 and result2 has changed
this has no effect in visual studio but it's usefull when
using gcc and options like -O
*/
uint result1_;
uint result2_;
#ifndef __GNUC__
#if defined(_MSC_VER)
result1_ = _umul128(a,b,&result2_);
#else
#error "another compiler than GCC is currently not supported in 64bit mode"
#endif
#endif
#ifdef __GNUC__
__asm__ (
"mulq %%rdx \n"
: "=a" (result1_), "=d" (result2_)
: "0" (a), "1" (b)
: "cc" );
#endif
*result_low = result1_;
*result_high = result2_;
}
/*!
*
* Division
*
*
*/
#ifndef __GNUC__
/*!
this method calculates 64bits word a:b / 32bits c (a higher, b lower word)
r = a:b / c and rest - remainder
***this method is created only on a 64bit platform***
*
* WARNING:
* if r (one word) is too small for the result or c is equal zero
* there'll be a hardware interruption (0)
* and probably the end of your program
*
*/
template<uint value_size>
void UInt<value_size>::DivTwoWords(uint a,uint b, uint c, uint * r, uint * rest)
{
uint r_;
uint rest_;
/*
these variables have similar meaning like those in
the multiplication algorithm MulTwoWords
*/
TTMATH_ASSERT( c != 0 )
#ifndef __GNUC__
#if defined(_MSC_VER)
div_x64(&a,&b,c);
r_ = a;
rest_ = b;
#else
#error "another compiler than GCC is currently not supported in 64bit mode"
#endif
#endif
#ifdef __GNUC__
__asm__ (
"divq %%rcx \n"
: "=a" (r_), "=d" (rest_)
: "d" (a), "a" (b), "c" (c)
: "cc" );
#endif
*r = r_;
*rest = rest_;
}
template<uint value_size>
uint UInt<value_size>::AddTwoWords(uint a, uint b, uint carry, uint * result)
{
uint temp;
if( carry == 0 )
{
temp = a + b;
if( temp < a )
carry = 1;
}
else
{
carry = 1;
temp = a + b + carry;
if( temp > a ) // !(temp<=a)
carry = 0;
}
*result = temp;
return carry;
}
template<uint value_size>
uint UInt<value_size>::SubTwoWords(uint a, uint b, uint carry, uint * result)
{
if( carry == 0 )
{
*result = a - b;
if( a < b )
carry = 1;
}
else
{
carry = 1;
*result = a - b - carry;
if( a > b ) // !(a <= b )
carry = 0;
}
return carry;
}
/*!
this static method addes one vector to the other
'ss1' is larger in size or equal to 'ss2'
ss1 points to the first (larger) vector
ss2 points to the second vector
ss1_size - size of the ss1 (and size of the result too)
ss2_size - size of the ss2
result - is the result vector (which has size the same as ss1: ss1_size)
Example: ss1_size is 5, ss2_size is 3
ss1: ss2: result (output):
5 1 5+1
4 3 4+3
2 7 2+7
6 6
9 9
of course the carry is propagated and will be returned from the last item
(this method is used by the Karatsuba multiplication algorithm)
*/
template<uint value_size>
uint UInt<value_size>::AddVector(const uint * ss1, const uint * ss2, uint ss1_size, uint ss2_size, uint * result)
{
uint i, c = 0;
TTMATH_ASSERT( ss1_size >= ss2_size )
for(i=0 ; i<ss2_size ; ++i)
c = AddTwoWords(ss1[i], ss2[i], c, &result[i]);
for( ; i<ss1_size ; ++i)
c = AddTwoWords(ss1[i], 0, c, &result[i]);
TTMATH_LOG("UInt::AddVector")
return c;
}
/*!
this static method subtractes one vector from the other
'ss1' is larger in size or equal to 'ss2'
ss1 points to the first (larger) vector
ss2 points to the second vector
ss1_size - size of the ss1 (and size of the result too)
ss2_size - size of the ss2
result - is the result vector (which has size the same as ss1: ss1_size)
Example: ss1_size is 5, ss2_size is 3
ss1: ss2: result (output):
5 1 5-1
4 3 4-3
2 7 2-7
6 6-1 (the borrow from previous item)
9 9
return (carry): 0
of course the carry (borrow) is propagated and will be returned from the last item
(this method is used by the Karatsuba multiplication algorithm)
*/
template<uint value_size>
uint UInt<value_size>::SubVector(const uint * ss1, const uint * ss2, uint ss1_size, uint ss2_size, uint * result)
{
uint i, c = 0;
TTMATH_ASSERT( ss1_size >= ss2_size )
for(i=0 ; i<ss2_size ; ++i)
c = SubTwoWords(ss1[i], ss2[i], c, &result[i]);
for( ; i<ss1_size ; ++i)
c = SubTwoWords(ss1[i], 0, c, &result[i]);
TTMATH_LOG("UInt::SubVector")
return c;
}
#endif // #ifndef __GNUC__
} //namespace
#endif //ifdef TTMATH_PLATFORM64
#endif //ifndef TTMATH_NOASM
#endif
Reference in New Issue View Git Blame Copy Permalink