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e93c264336
This came to light when adding hard-flaot support to ARC glibc port without hardware sqrt support causing glibc build to fail: | ../sysdeps/ieee754/dbl-64/e_sqrt.c: In function '__ieee754_sqrt': | ../sysdeps/ieee754/dbl-64/e_sqrt.c:58:54: error: unused variable 'ty' [-Werror=unused-variable] | double y, t, del, res, res1, hy, z, zz, p, hx, tx, ty, s; The reason being EMULV() macro uses the hardware provided __builtin_fma() variant, leaving temporary variables 'p, hx, tx, hy, ty' unused hence compiler warning and ensuing error. The intent of the patch was to fix that error, but EMULV is pervasive and used fair bit indirectly via othe rmacros, hence this patch. Functionally it should not result in code gen changes and if at all those would be better since the scope of those temporaries is greatly reduced now Built tested with aarch64-linux-gnu arm-linux-gnueabi arm-linux-gnueabihf hppa-linux-gnu x86_64-linux-gnu arm-linux-gnueabihf riscv64-linux-gnu-rv64imac-lp64 riscv64-linux-gnu-rv64imafdc-lp64 powerpc-linux-gnu microblaze-linux-gnu nios2-linux-gnu hppa-linux-gnu Also as suggested by Joseph [1] used --strip and compared the libs with and w/o patch and they are byte-for-byte unchanged (with gcc 9). | for i in `find . -name libm-2.31.9000.so`; | do | echo $i; diff $i /SCRATCH/vgupta/gnu2/install/glibcs/$i ; echo $?; | done | ./aarch64-linux-gnu/lib64/libm-2.31.9000.so | 0 | ./arm-linux-gnueabi/lib/libm-2.31.9000.so | 0 | ./x86_64-linux-gnu/lib64/libm-2.31.9000.so | 0 | ./arm-linux-gnueabihf/lib/libm-2.31.9000.so | 0 | ./riscv64-linux-gnu-rv64imac-lp64/lib64/lp64/libm-2.31.9000.so | 0 | ./riscv64-linux-gnu-rv64imafdc-lp64/lib64/lp64/libm-2.31.9000.so | 0 | ./powerpc-linux-gnu/lib/libm-2.31.9000.so | 0 | ./microblaze-linux-gnu/lib/libm-2.31.9000.so | 0 | ./nios2-linux-gnu/lib/libm-2.31.9000.so | 0 | ./hppa-linux-gnu/lib/libm-2.31.9000.so | 0 | ./s390x-linux-gnu/lib64/libm-2.31.9000.so [1] https://sourceware.org/pipermail/libc-alpha/2019-November/108267.html
188 lines
9.4 KiB
C
188 lines
9.4 KiB
C
/*
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* IBM Accurate Mathematical Library
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* Written by International Business Machines Corp.
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* Copyright (C) 2001-2020 Free Software Foundation, Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation; either version 2.1 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program; if not, see <https://www.gnu.org/licenses/>.
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*/
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#include <math.h>
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/***********************************************************************/
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/*MODULE_NAME: dla.h */
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/* */
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/* This file holds C language macros for 'Double Length Floating Point */
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/* Arithmetic'. The macros are based on the paper: */
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/* T.J.Dekker, "A floating-point Technique for extending the */
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/* Available Precision", Number. Math. 18, 224-242 (1971). */
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/* A Double-Length number is defined by a pair (r,s), of IEEE double */
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/* precision floating point numbers that satisfy, */
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/* */
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/* abs(s) <= abs(r+s)*2**(-53)/(1+2**(-53)). */
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/* */
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/* The computer arithmetic assumed is IEEE double precision in */
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/* round to nearest mode. All variables in the macros must be of type */
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/* IEEE double. */
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/***********************************************************************/
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/* CN = 1+2**27 = '41a0000002000000' IEEE double format. Use it to split a
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double for better accuracy. */
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#define CN 134217729.0
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/* Exact addition of two single-length floating point numbers, Dekker. */
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/* The macro produces a double-length number (z,zz) that satisfies */
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/* z+zz = x+y exactly. */
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#define EADD(x,y,z,zz) \
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z=(x)+(y); zz=(fabs(x)>fabs(y)) ? (((x)-(z))+(y)) : (((y)-(z))+(x));
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/* Exact subtraction of two single-length floating point numbers, Dekker. */
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/* The macro produces a double-length number (z,zz) that satisfies */
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/* z+zz = x-y exactly. */
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#define ESUB(x,y,z,zz) \
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z=(x)-(y); zz=(fabs(x)>fabs(y)) ? (((x)-(z))-(y)) : ((x)-((y)+(z)));
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#ifdef __FP_FAST_FMA
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# define DLA_FMS(x, y, z) __builtin_fma (x, y, -(z))
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#endif
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/* Exact multiplication of two single-length floating point numbers, */
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/* Veltkamp. The macro produces a double-length number (z,zz) that */
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/* satisfies z+zz = x*y exactly. p,hx,tx,hy,ty are temporary */
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/* storage variables of type double. */
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#ifdef DLA_FMS
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# define EMULV(x, y, z, zz) \
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z = x * y; zz = DLA_FMS (x, y, z);
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#else
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# define EMULV(x, y, z, zz) \
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({ __typeof__ (x) __p, hx, tx, hy, ty; \
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__p = CN * (x); hx = ((x) - __p) + __p; tx = (x) - hx; \
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__p = CN * (y); hy = ((y) - __p) + __p; ty = (y) - hy; \
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z = (x) * (y); zz = (((hx * hy - z) + hx * ty) + tx * hy) + tx * ty; \
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})
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#endif
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/* Exact multiplication of two single-length floating point numbers, Dekker. */
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/* The macro produces a nearly double-length number (z,zz) (see Dekker) */
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/* that satisfies z+zz = x*y exactly. p,hx,tx,hy,ty,q are temporary */
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/* storage variables of type double. */
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#ifdef DLA_FMS
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# define MUL12(x, y, z, zz) \
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EMULV(x, y, z, zz)
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#else
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# define MUL12(x, y, z, zz) \
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({ __typeof__ (x) __p, hx, tx, hy, ty, __q; \
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__p=CN*(x); hx=((x)-__p)+__p; tx=(x)-hx; \
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__p=CN*(y); hy=((y)-__p)+__p; ty=(y)-hy; \
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__p=hx*hy; __q=hx*ty+tx*hy; z=__p+__q; zz=((__p-z)+__q)+tx*ty; \
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})
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#endif
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/* Double-length addition, Dekker. The macro produces a double-length */
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/* number (z,zz) which satisfies approximately z+zz = x+xx + y+yy. */
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/* An error bound: (abs(x+xx)+abs(y+yy))*4.94e-32. (x,xx), (y,yy) */
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/* are assumed to be double-length numbers. r,s are temporary */
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/* storage variables of type double. */
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#define ADD2(x, xx, y, yy, z, zz, r, s) \
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r = (x) + (y); s = (fabs (x) > fabs (y)) ? \
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(((((x) - r) + (y)) + (yy)) + (xx)) : \
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(((((y) - r) + (x)) + (xx)) + (yy)); \
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z = r + s; zz = (r - z) + s;
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/* Double-length subtraction, Dekker. The macro produces a double-length */
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/* number (z,zz) which satisfies approximately z+zz = x+xx - (y+yy). */
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/* An error bound: (abs(x+xx)+abs(y+yy))*4.94e-32. (x,xx), (y,yy) */
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/* are assumed to be double-length numbers. r,s are temporary */
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/* storage variables of type double. */
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#define SUB2(x, xx, y, yy, z, zz, r, s) \
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r = (x) - (y); s = (fabs (x) > fabs (y)) ? \
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(((((x) - r) - (y)) - (yy)) + (xx)) : \
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((((x) - ((y) + r)) + (xx)) - (yy)); \
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z = r + s; zz = (r - z) + s;
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/* Double-length multiplication, Dekker. The macro produces a double-length */
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/* number (z,zz) which satisfies approximately z+zz = (x+xx)*(y+yy). */
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/* An error bound: abs((x+xx)*(y+yy))*1.24e-31. (x,xx), (y,yy) */
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/* are assumed to be double-length numbers. p,hx,tx,hy,ty,q,c,cc are */
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/* temporary storage variables of type double. */
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#define MUL2(x, xx, y, yy, z, zz, c, cc) \
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MUL12 (x, y, c, cc); \
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cc = ((x) * (yy) + (xx) * (y)) + cc; z = c + cc; zz = (c - z) + cc;
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/* Double-length division, Dekker. The macro produces a double-length */
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/* number (z,zz) which satisfies approximately z+zz = (x+xx)/(y+yy). */
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/* An error bound: abs((x+xx)/(y+yy))*1.50e-31. (x,xx), (y,yy) */
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/* are assumed to be double-length numbers. p,hx,tx,hy,ty,q,c,cc,u,uu */
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/* are temporary storage variables of type double. */
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#define DIV2(x, xx, y, yy, z, zz, c, cc, u, uu) \
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c=(x)/(y); MUL12(c,y,u,uu); \
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cc=(((((x)-u)-uu)+(xx))-c*(yy))/(y); z=c+cc; zz=(c-z)+cc;
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/* Double-length addition, slower but more accurate than ADD2. */
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/* The macro produces a double-length */
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/* number (z,zz) which satisfies approximately z+zz = (x+xx)+(y+yy). */
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/* An error bound: abs(x+xx + y+yy)*1.50e-31. (x,xx), (y,yy) */
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/* are assumed to be double-length numbers. r,rr,s,ss,u,uu,w */
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/* are temporary storage variables of type double. */
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#define ADD2A(x, xx, y, yy, z, zz, r, rr, s, ss, u, uu, w) \
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r = (x) + (y); \
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if (fabs (x) > fabs (y)) { rr = ((x) - r) + (y); s = (rr + (yy)) + (xx); } \
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else { rr = ((y) - r) + (x); s = (rr + (xx)) + (yy); } \
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if (rr != 0.0) { \
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z = r + s; zz = (r - z) + s; } \
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else { \
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ss = (fabs (xx) > fabs (yy)) ? (((xx) - s) + (yy)) : (((yy) - s) + (xx));\
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u = r + s; \
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uu = (fabs (r) > fabs (s)) ? ((r - u) + s) : ((s - u) + r); \
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w = uu + ss; z = u + w; \
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zz = (fabs (u) > fabs (w)) ? ((u - z) + w) : ((w - z) + u); }
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/* Double-length subtraction, slower but more accurate than SUB2. */
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/* The macro produces a double-length */
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/* number (z,zz) which satisfies approximately z+zz = (x+xx)-(y+yy). */
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/* An error bound: abs(x+xx - (y+yy))*1.50e-31. (x,xx), (y,yy) */
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/* are assumed to be double-length numbers. r,rr,s,ss,u,uu,w */
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/* are temporary storage variables of type double. */
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#define SUB2A(x, xx, y, yy, z, zz, r, rr, s, ss, u, uu, w) \
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r = (x) - (y); \
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if (fabs (x) > fabs (y)) { rr = ((x) - r) - (y); s = (rr - (yy)) + (xx); } \
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else { rr = (x) - ((y) + r); s = (rr + (xx)) - (yy); } \
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if (rr != 0.0) { \
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z = r + s; zz = (r - z) + s; } \
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else { \
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ss = (fabs (xx) > fabs (yy)) ? (((xx) - s) - (yy)) : ((xx) - ((yy) + s)); \
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u = r + s; \
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uu = (fabs (r) > fabs (s)) ? ((r - u) + s) : ((s - u) + r); \
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w = uu + ss; z = u + w; \
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zz = (fabs (u) > fabs (w)) ? ((u - z) + w) : ((w - z) + u); }
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