> > diff --git a/arch/powerpc/include/asm/sfp-machine.h > b/arch/powerpc/include/asm/sfp-machine.h > new file mode 100644 > index 0000000..ced34f1 > --- /dev/null > +++ b/arch/powerpc/include/asm/sfp-machine.h > @@ -0,0 +1,353 @@ > +/* Machine-dependent software floating-point definitions. > PPC version. > + Copyright (C) 1997 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Library General > Public License as > + published by the Free Software Foundation; either version 2 of the > + License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will > be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Library General Public License for more details. > + > + You should have received a copy of the GNU Library General Public > + License along with the GNU C Library; see the file > COPYING.LIB. If > + not, write to the Free Software Foundation, Inc., > + 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. > + > + Actually, this is a PPC (32bit) version, written based on the > + i386, sparc, and sparc64 versions, by me, > + Peter Maydell ([EMAIL PROTECTED]). > + Comments are by and large also mine, although they may be > inaccurate. > + > + In picking out asm fragments I've gone with the lowest common > + denominator, which also happens to be the hardware I have :-> > + That is, a SPARC without hardware multiply and divide. > + */ > + > +/* basic word size definitions */ > +#define _FP_W_TYPE_SIZE 32 > +#define _FP_W_TYPE unsigned long > +#define _FP_WS_TYPE signed long > +#define _FP_I_TYPE long > + > +#define __ll_B ((UWtype) 1 << > (W_TYPE_SIZE / 2)) > +#define __ll_lowpart(t) ((UWtype) (t) & (__ll_B - 1)) > +#define __ll_highpart(t) ((UWtype) (t) >> (W_TYPE_SIZE / 2)) > + > +/* You can optionally code some things like addition in asm. For > + * example, i386 defines __FP_FRAC_ADD_2 as asm. If you don't > + * then you get a fragment of C code [if you change an #ifdef 0 > + * in op-2.h] or a call to add_ssaaaa (see below). > + * Good places to look for asm fragments to use are gcc and glibc. > + * gcc's longlong.h is useful. > + */ > + > +/* We need to know how to multiply and divide. If the host word size > + * is >= 2*fracbits you can use FP_MUL_MEAT_n_imm(t,R,X,Y) which > + * codes the multiply with whatever gcc does to 'a * b'. > + * _FP_MUL_MEAT_n_wide(t,R,X,Y,f) is used when you have an asm > + * function that can multiply two 1W values and get a 2W result. > + * Otherwise you're stuck with _FP_MUL_MEAT_n_hard(t,R,X,Y) which > + * does bitshifting to avoid overflow. > + * For division there is FP_DIV_MEAT_n_imm(t,R,X,Y,f) for word size > + * >= 2*fracbits, where f is either _FP_DIV_HELP_imm or > + * _FP_DIV_HELP_ldiv (see op-1.h). > + * _FP_DIV_MEAT_udiv() is if you have asm to do 2W/1W => (1W, 1W). > + * [GCC and glibc have longlong.h which has the asm macro udiv_qrnnd > + * to do this.] > + * In general, 'n' is the number of words required to hold the type, > + * and 't' is either S, D or Q for single/double/quad. > + * -- PMM > + */ > +/* Example: SPARC64: > + * #define _FP_MUL_MEAT_S(R,X,Y) _FP_MUL_MEAT_1_imm(S,R,X,Y) > + * #define _FP_MUL_MEAT_D(R,X,Y) > _FP_MUL_MEAT_1_wide(D,R,X,Y,umul_ppmm) > + * #define _FP_MUL_MEAT_Q(R,X,Y) > _FP_MUL_MEAT_2_wide(Q,R,X,Y,umul_ppmm) > + * > + * #define _FP_DIV_MEAT_S(R,X,Y) > _FP_DIV_MEAT_1_imm(S,R,X,Y,_FP_DIV_HELP_imm) > + * #define _FP_DIV_MEAT_D(R,X,Y) _FP_DIV_MEAT_1_udiv(D,R,X,Y) > + * #define _FP_DIV_MEAT_Q(R,X,Y) _FP_DIV_MEAT_2_udiv_64(Q,R,X,Y) > + * > + * Example: i386: > + * #define _FP_MUL_MEAT_S(R,X,Y) > _FP_MUL_MEAT_1_wide(S,R,X,Y,_i386_mul_32_64) > + * #define _FP_MUL_MEAT_D(R,X,Y) > _FP_MUL_MEAT_2_wide(D,R,X,Y,_i386_mul_32_64) > + * > + * #define _FP_DIV_MEAT_S(R,X,Y) > _FP_DIV_MEAT_1_udiv(S,R,X,Y,_i386_div_64_32) > + * #define _FP_DIV_MEAT_D(R,X,Y) _FP_DIV_MEAT_2_udiv_64(D,R,X,Y) > + */ > + > +#define _FP_MUL_MEAT_S(R,X,Y) > _FP_MUL_MEAT_1_wide(_FP_WFRACBITS_S,R,X,Y,umul_ppmm) > +#define _FP_MUL_MEAT_D(R,X,Y) > _FP_MUL_MEAT_2_wide(_FP_WFRACBITS_D,R,X,Y,umul_ppmm) > + > +#define _FP_DIV_MEAT_S(R,X,Y) _FP_DIV_MEAT_1_udiv(S,R,X,Y)
It seems _FP_DIV_MEAT_S() should be defined to _FP_DIV_MEAT_1_udiv_norm(). I can't remember very clear, but it seems single point float need to be normalized before calling udiv_qrnnd. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
