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375ecf678c
Update the vendored TomsFastMath (TFM) library to v0.13.1. Resolves: https://bugzilla.clamav.net/show_bug.cgi?id=11992 I removed compatibility macro's from when libTomMath was used. This required removing a bunch of faux-error handling because the fast-math equivalent functions return void, and cannot fail. The previous version used had named the header "bignum_fast.h" instead of "tfm.h" and had customizations in that header to enable TFM_CHECK all the time, and also TFM_NO_ASM if __GNUC__ not defined or if the system isn't 64bit architecture. This update uses tfm.h as-is, and has CMake define TFM_CHECK and TFM_NO_ASM as needed. I've kept bignum.h as an interface to including tfm.h so that in the future we can more easily add support for system-installed TomsFastMath instead of the vendored one, taking inspiration from Debian's patch to support system-TomsFastMath. See: https://salsa.debian.org/clamav-team/clamav/-/blob/unstable/debian/patches/add-support-for-system-tomsfastmath.patch
53 lines
1.1 KiB
C
53 lines
1.1 KiB
C
/* TomsFastMath, a fast ISO C bignum library.
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*
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* This project is meant to fill in where LibTomMath
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* falls short. That is speed ;-)
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*
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* 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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*/
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#include <tfm_private.h>
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/* b = a/2 */
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void fp_div_2(fp_int * a, fp_int * b)
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{
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int x, oldused;
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oldused = b->used;
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b->used = a->used;
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{
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register fp_digit r, rr, *tmpa, *tmpb;
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/* source alias */
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tmpa = a->dp + b->used - 1;
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/* dest alias */
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tmpb = b->dp + b->used - 1;
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/* carry */
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r = 0;
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for (x = b->used - 1; x >= 0; x--) {
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/* get the carry for the next iteration */
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rr = *tmpa & 1;
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/* shift the current digit, add in carry and store */
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*tmpb-- = (*tmpa-- >> 1) | (r << (DIGIT_BIT - 1));
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/* forward carry to next iteration */
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r = rr;
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}
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/* zero excess digits */
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tmpb = b->dp + b->used;
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for (x = b->used; x < oldused; x++) {
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*tmpb++ = 0;
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}
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}
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b->sign = a->sign;
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fp_clamp (b);
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}
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/* $Source$ */
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/* $Revision$ */
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/* $Date$ */
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