denyhosts/clamav/libclamav/tomsfastmath/mont/fp_montgomery_reduce.c

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/* TomsFastMath, a fast ISO C bignum library.
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*
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* This project is meant to fill in where LibTomMath
* falls short. That is speed ;-)
*
* This project is public domain and free for all purposes.
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*
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* Tom St Denis, tomstdenis@gmail.com
*/
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#include <tfm_private.h>
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/******************************************************************/
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#if defined(TFM_X86) && !defined(TFM_SSE2)
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/* x86-32 code */
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#define MONT_START
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#define MONT_FINI
#define LOOP_END
#define LOOP_START \
mu = c[x] * mp
#define INNERMUL \
asm( \
"movl %5,%%eax \n\t" \
"mull %4 \n\t" \
"addl %1,%%eax \n\t" \
"adcl $0,%%edx \n\t" \
"addl %%eax,%0 \n\t" \
"adcl $0,%%edx \n\t" \
"movl %%edx,%1 \n\t" \
:"=g"(_c[LO]), "=r"(cy) \
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:"0"(_c[LO]), "1"(cy), "r"(mu), "r"(*tmpm++) \
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: "%eax", "%edx", "cc")
#define PROPCARRY \
asm( \
"addl %1,%0 \n\t" \
"setb %%al \n\t" \
"movzbl %%al,%1 \n\t" \
:"=g"(_c[LO]), "=r"(cy) \
:"0"(_c[LO]), "1"(cy) \
: "%eax", "cc")
/******************************************************************/
#elif defined(TFM_X86_64)
/* x86-64 code */
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#define MONT_START
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#define MONT_FINI
#define LOOP_END
#define LOOP_START \
mu = c[x] * mp
#define INNERMUL \
asm( \
"movq %5,%%rax \n\t" \
"mulq %4 \n\t" \
"addq %1,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"addq %%rax,%0 \n\t" \
"adcq $0,%%rdx \n\t" \
"movq %%rdx,%1 \n\t" \
:"=g"(_c[LO]), "=r"(cy) \
:"0"(_c[LO]), "1"(cy), "r"(mu), "r"(*tmpm++) \
: "%rax", "%rdx", "cc")
#define INNERMUL8 \
asm( \
"movq 0(%5),%%rax \n\t" \
"movq 0(%2),%%r10 \n\t" \
"movq 0x8(%5),%%r11 \n\t" \
"mulq %4 \n\t" \
"addq %%r10,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq 0x8(%2),%%r10 \n\t" \
"addq %3,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq %%rax,0(%0) \n\t" \
"movq %%rdx,%1 \n\t" \
\
"movq %%r11,%%rax \n\t" \
"movq 0x10(%5),%%r11 \n\t" \
"mulq %4 \n\t" \
"addq %%r10,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq 0x10(%2),%%r10 \n\t" \
"addq %3,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq %%rax,0x8(%0) \n\t" \
"movq %%rdx,%1 \n\t" \
\
"movq %%r11,%%rax \n\t" \
"movq 0x18(%5),%%r11 \n\t" \
"mulq %4 \n\t" \
"addq %%r10,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq 0x18(%2),%%r10 \n\t" \
"addq %3,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq %%rax,0x10(%0) \n\t" \
"movq %%rdx,%1 \n\t" \
\
"movq %%r11,%%rax \n\t" \
"movq 0x20(%5),%%r11 \n\t" \
"mulq %4 \n\t" \
"addq %%r10,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq 0x20(%2),%%r10 \n\t" \
"addq %3,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq %%rax,0x18(%0) \n\t" \
"movq %%rdx,%1 \n\t" \
\
"movq %%r11,%%rax \n\t" \
"movq 0x28(%5),%%r11 \n\t" \
"mulq %4 \n\t" \
"addq %%r10,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq 0x28(%2),%%r10 \n\t" \
"addq %3,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq %%rax,0x20(%0) \n\t" \
"movq %%rdx,%1 \n\t" \
\
"movq %%r11,%%rax \n\t" \
"movq 0x30(%5),%%r11 \n\t" \
"mulq %4 \n\t" \
"addq %%r10,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq 0x30(%2),%%r10 \n\t" \
"addq %3,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq %%rax,0x28(%0) \n\t" \
"movq %%rdx,%1 \n\t" \
\
"movq %%r11,%%rax \n\t" \
"movq 0x38(%5),%%r11 \n\t" \
"mulq %4 \n\t" \
"addq %%r10,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq 0x38(%2),%%r10 \n\t" \
"addq %3,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq %%rax,0x30(%0) \n\t" \
"movq %%rdx,%1 \n\t" \
\
"movq %%r11,%%rax \n\t" \
"mulq %4 \n\t" \
"addq %%r10,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"addq %3,%%rax \n\t" \
"adcq $0,%%rdx \n\t" \
"movq %%rax,0x38(%0) \n\t" \
"movq %%rdx,%1 \n\t" \
\
:"=r"(_c), "=r"(cy) \
: "0"(_c), "1"(cy), "g"(mu), "r"(tmpm)\
: "%rax", "%rdx", "%r10", "%r11", "cc")
#define PROPCARRY \
asm( \
"addq %1,%0 \n\t" \
"setb %%al \n\t" \
"movzbq %%al,%1 \n\t" \
:"=g"(_c[LO]), "=r"(cy) \
:"0"(_c[LO]), "1"(cy) \
: "%rax", "cc")
/******************************************************************/
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#elif defined(TFM_SSE2)
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/* SSE2 code (assumes 32-bit fp_digits) */
/* XMM register assignments:
* xmm0 *tmpm++, then Mu * (*tmpm++)
* xmm1 c[x], then Mu
* xmm2 mp
* xmm3 cy
* xmm4 _c[LO]
*/
#define MONT_START \
asm("movd %0,%%mm2"::"g"(mp))
#define MONT_FINI \
asm("emms")
#define LOOP_START \
asm( \
"movd %0,%%mm1 \n\t" \
"pxor %%mm3,%%mm3 \n\t" \
"pmuludq %%mm2,%%mm1 \n\t" \
:: "g"(c[x]))
/* pmuludq on mmx registers does a 32x32->64 multiply. */
#define INNERMUL \
asm( \
"movd %1,%%mm4 \n\t" \
"movd %2,%%mm0 \n\t" \
"paddq %%mm4,%%mm3 \n\t" \
"pmuludq %%mm1,%%mm0 \n\t" \
"paddq %%mm0,%%mm3 \n\t" \
"movd %%mm3,%0 \n\t" \
"psrlq $32, %%mm3 \n\t" \
:"=g"(_c[LO]) : "0"(_c[LO]), "g"(*tmpm++) );
#define INNERMUL8 \
asm( \
"movd 0(%1),%%mm4 \n\t" \
"movd 0(%2),%%mm0 \n\t" \
"paddq %%mm4,%%mm3 \n\t" \
"pmuludq %%mm1,%%mm0 \n\t" \
"movd 4(%2),%%mm5 \n\t" \
"paddq %%mm0,%%mm3 \n\t" \
"movd 4(%1),%%mm6 \n\t" \
"movd %%mm3,0(%0) \n\t" \
"psrlq $32, %%mm3 \n\t" \
\
"paddq %%mm6,%%mm3 \n\t" \
"pmuludq %%mm1,%%mm5 \n\t" \
"movd 8(%2),%%mm6 \n\t" \
"paddq %%mm5,%%mm3 \n\t" \
"movd 8(%1),%%mm7 \n\t" \
"movd %%mm3,4(%0) \n\t" \
"psrlq $32, %%mm3 \n\t" \
\
"paddq %%mm7,%%mm3 \n\t" \
"pmuludq %%mm1,%%mm6 \n\t" \
"movd 12(%2),%%mm7 \n\t" \
"paddq %%mm6,%%mm3 \n\t" \
"movd 12(%1),%%mm5 \n\t" \
"movd %%mm3,8(%0) \n\t" \
"psrlq $32, %%mm3 \n\t" \
\
"paddq %%mm5,%%mm3 \n\t" \
"pmuludq %%mm1,%%mm7 \n\t" \
"movd 16(%2),%%mm5 \n\t" \
"paddq %%mm7,%%mm3 \n\t" \
"movd 16(%1),%%mm6 \n\t" \
"movd %%mm3,12(%0) \n\t" \
"psrlq $32, %%mm3 \n\t" \
\
"paddq %%mm6,%%mm3 \n\t" \
"pmuludq %%mm1,%%mm5 \n\t" \
"movd 20(%2),%%mm6 \n\t" \
"paddq %%mm5,%%mm3 \n\t" \
"movd 20(%1),%%mm7 \n\t" \
"movd %%mm3,16(%0) \n\t" \
"psrlq $32, %%mm3 \n\t" \
\
"paddq %%mm7,%%mm3 \n\t" \
"pmuludq %%mm1,%%mm6 \n\t" \
"movd 24(%2),%%mm7 \n\t" \
"paddq %%mm6,%%mm3 \n\t" \
"movd 24(%1),%%mm5 \n\t" \
"movd %%mm3,20(%0) \n\t" \
"psrlq $32, %%mm3 \n\t" \
\
"paddq %%mm5,%%mm3 \n\t" \
"pmuludq %%mm1,%%mm7 \n\t" \
"movd 28(%2),%%mm5 \n\t" \
"paddq %%mm7,%%mm3 \n\t" \
"movd 28(%1),%%mm6 \n\t" \
"movd %%mm3,24(%0) \n\t" \
"psrlq $32, %%mm3 \n\t" \
\
"paddq %%mm6,%%mm3 \n\t" \
"pmuludq %%mm1,%%mm5 \n\t" \
"paddq %%mm5,%%mm3 \n\t" \
"movd %%mm3,28(%0) \n\t" \
"psrlq $32, %%mm3 \n\t" \
:"=r"(_c) : "0"(_c), "g"(tmpm) );
#define LOOP_END \
asm( "movd %%mm3,%0 \n" :"=r"(cy))
#define PROPCARRY \
asm( \
"addl %1,%0 \n\t" \
"setb %%al \n\t" \
"movzbl %%al,%1 \n\t" \
:"=g"(_c[LO]), "=r"(cy) \
:"0"(_c[LO]), "1"(cy) \
: "%eax", "cc")
/******************************************************************/
#elif defined(TFM_ARM)
/* ARMv4 code */
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#define MONT_START
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#define MONT_FINI
#define LOOP_END
#define LOOP_START \
mu = c[x] * mp
#define INNERMUL \
asm( \
" LDR r0,%1 \n\t" \
" ADDS r0,r0,%0 \n\t" \
" MOVCS %0,#1 \n\t" \
" MOVCC %0,#0 \n\t" \
" UMLAL r0,%0,%3,%4 \n\t" \
" STR r0,%1 \n\t" \
:"=r"(cy),"=m"(_c[0]):"0"(cy),"r"(mu),"r"(*tmpm++),"1"(_c[0]):"r0","cc");
#define PROPCARRY \
asm( \
" LDR r0,%1 \n\t" \
" ADDS r0,r0,%0 \n\t" \
" STR r0,%1 \n\t" \
" MOVCS %0,#1 \n\t" \
" MOVCC %0,#0 \n\t" \
:"=r"(cy),"=m"(_c[0]):"0"(cy),"1"(_c[0]):"r0","cc");
/******************************************************************/
#elif defined(TFM_PPC32)
/* PPC32 */
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#define MONT_START
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#define MONT_FINI
#define LOOP_END
#define LOOP_START \
mu = c[x] * mp
#define INNERMUL \
asm( \
" mullw 16,%3,%4 \n\t" \
" mulhwu 17,%3,%4 \n\t" \
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" addc 16,16,%2 \n\t" \
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" addze 17,17 \n\t" \
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" addc %1,16,%5 \n\t" \
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" addze %0,17 \n\t" \
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:"=r"(cy),"=r"(_c[0]):"0"(cy),"r"(mu),"r"(tmpm[0]),"1"(_c[0]):"16", "17", "cc"); ++tmpm;
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#define PROPCARRY \
asm( \
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" addc %1,%3,%2 \n\t" \
" xor %0,%2,%2 \n\t" \
" addze %0,%2 \n\t" \
:"=r"(cy),"=r"(_c[0]):"0"(cy),"1"(_c[0]):"cc");
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/******************************************************************/
#elif defined(TFM_PPC64)
/* PPC64 */
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#define MONT_START
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#define MONT_FINI
#define LOOP_END
#define LOOP_START \
mu = c[x] * mp
#define INNERMUL \
asm( \
" mulld r16,%3,%4 \n\t" \
" mulhdu r17,%3,%4 \n\t" \
" addc r16,16,%0 \n\t" \
" addze r17,r17 \n\t" \
" ldx r18,0,%1 \n\t" \
" addc r16,r16,r18 \n\t" \
" addze %0,r17 \n\t" \
" sdx r16,0,%1 \n\t" \
:"=r"(cy),"=m"(_c[0]):"0"(cy),"r"(mu),"r"(tmpm[0]),"1"(_c[0]):"r16", "r17", "r18","cc"); ++tmpm;
#define PROPCARRY \
asm( \
" ldx r16,0,%1 \n\t" \
" addc r16,r16,%0 \n\t" \
" sdx r16,0,%1 \n\t" \
" xor %0,%0,%0 \n\t" \
" addze %0,%0 \n\t" \
:"=r"(cy),"=m"(_c[0]):"0"(cy),"1"(_c[0]):"r16","cc");
/******************************************************************/
#elif defined(TFM_AVR32)
/* AVR32 */
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#define MONT_START
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#define MONT_FINI
#define LOOP_END
#define LOOP_START \
mu = c[x] * mp
#define INNERMUL \
asm( \
" ld.w r2,%1 \n\t" \
" add r2,%0 \n\t" \
" eor r3,r3 \n\t" \
" acr r3 \n\t" \
" macu.d r2,%3,%4 \n\t" \
" st.w %1,r2 \n\t" \
" mov %0,r3 \n\t" \
:"=r"(cy),"=r"(_c):"0"(cy),"r"(mu),"r"(*tmpm++),"1"(_c):"r2","r3");
#define PROPCARRY \
asm( \
" ld.w r2,%1 \n\t" \
" add r2,%0 \n\t" \
" st.w %1,r2 \n\t" \
" eor %0,%0 \n\t" \
" acr %0 \n\t" \
:"=r"(cy),"=r"(&_c[0]):"0"(cy),"1"(&_c[0]):"r2","cc");
/******************************************************************/
#elif defined(TFM_MIPS)
/* MIPS */
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#define MONT_START
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#define MONT_FINI
#define LOOP_END
#define LOOP_START \
mu = c[x] * mp
#define INNERMUL \
asm( \
" multu %3,%4 \n\t" \
" mflo $12 \n\t" \
" mfhi $13 \n\t" \
" addu $12,$12,%0 \n\t" \
" sltu $10,$12,%0 \n\t" \
" addu $13,$13,$10 \n\t" \
" lw $10,%1 \n\t" \
" addu $12,$12,$10 \n\t" \
" sltu $10,$12,$10 \n\t" \
" addu %0,$13,$10 \n\t" \
" sw $12,%1 \n\t" \
:"=r"(cy),"=m"(_c[0]):"0"(cy),"r"(mu),"r"(tmpm[0]),"1"(_c[0]):"$10","$12","$13"); ++tmpm;
#define PROPCARRY \
asm( \
" lw $10,%1 \n\t" \
" addu $10,$10,%0 \n\t" \
" sw $10,%1 \n\t" \
" sltu %0,$10,%0 \n\t" \
:"=r"(cy),"=m"(_c[0]):"0"(cy),"1"(_c[0]):"$10");
/******************************************************************/
#else
/* ISO C code */
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#define MONT_START
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#define MONT_FINI
#define LOOP_END
#define LOOP_START \
mu = c[x] * mp
#define INNERMUL \
do { fp_word t; \
_c[0] = t = ((fp_word)_c[0] + (fp_word)cy) + \
(((fp_word)mu) * ((fp_word)*tmpm++)); \
cy = (t >> DIGIT_BIT); \
} while (0)
#define PROPCARRY \
do { fp_digit t = _c[0] += cy; cy = (t < cy); } while (0)
#endif
/******************************************************************/
#define LO 0
#ifdef TFM_SMALL_MONT_SET
#include "fp_mont_small.i"
#endif
/* computes x/R == x (mod N) via Montgomery Reduction */
void fp_montgomery_reduce(fp_int *a, fp_int *m, fp_digit mp)
{
fp_digit c[FP_SIZE], *_c, *tmpm, mu;
int oldused, x, y, pa;
/* bail if too large */
if (m->used > (FP_SIZE/2)) {
return;
}
#ifdef TFM_SMALL_MONT_SET
if (m->used <= 16) {
fp_montgomery_reduce_small(a, m, mp);
return;
}
#endif
#if defined(USE_MEMSET)
/* now zero the buff */
memset(c, 0, sizeof c);
#endif
pa = m->used;
/* copy the input */
oldused = a->used;
for (x = 0; x < oldused; x++) {
c[x] = a->dp[x];
}
#if !defined(USE_MEMSET)
for (; x < 2*pa+1; x++) {
c[x] = 0;
}
#endif
MONT_START;
for (x = 0; x < pa; x++) {
fp_digit cy = 0;
/* get Mu for this round */
LOOP_START;
_c = c + x;
tmpm = m->dp;
y = 0;
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#if defined(INNERMUL8)
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for (; y < (pa & ~7); y += 8) {
INNERMUL8;
_c += 8;
tmpm += 8;
}
#endif
for (; y < pa; y++) {
INNERMUL;
++_c;
}
LOOP_END;
while (cy) {
PROPCARRY;
++_c;
}
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}
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/* now copy out */
_c = c + pa;
tmpm = a->dp;
for (x = 0; x < pa+1; x++) {
*tmpm++ = *_c++;
}
for (; x < oldused; x++) {
*tmpm++ = 0;
}
MONT_FINI;
a->used = pa+1;
fp_clamp(a);
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/* if A >= m then A = A - m */
if (fp_cmp_mag (a, m) != FP_LT) {
s_fp_sub (a, m, a);
}
}
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/* $Source$ */
/* $Revision$ */
/* $Date$ */