On Fri, Aug 26, 2022 at 1:45 PM Corinna Vinschen wrote: > On Aug 26 10:45, Joel Sherrill wrote: > > On Fri, Aug 26, 2022 at 10:05 AM Corinna Vinschen > > wrote: > > > No, I wrote, create a *single* _fpmath.h file with the massive amount > > > of definitions (*all* seven) based on LDBL_MANT_DIG. > > > > > > There are very few special targets, like x86/x86_64 which need a tweak > > > in the macros, most of the time the macros should be the same. > > > > > > Instead of having 61 files, only have one. In theory there should be > > > only two definitions for targets with LDBL_MANT_DIG == DBL_MANT_DIG > > > to support little and big endian, more shouldn't be required. > > > > > > For all others, we already have *ieee*.h files with matching > definitions > > > which can be used as role models for the various (but few) definitions > of > > > union IEEEl2bits. See, for instance, > newlib/libc/include/machine/ieee.h. > > > > > > > This approach works and doesn't abandon the targets which the > > > > ldbl==dbl method works for. > > > > > > I never said to abandon these targets, but fwiw, I think you're > > > overestimating the complexity to generate a single _fpmath.h > > > file with matching definitions for these targes as well. The > > > information is basically already present in newlib. > > > > > So don't preserve the FreeBSD files as close to a direct copy > > as possible? > > We're only talking about the _fpmath.h files, not all the other > files. > > If you like, copy over the handful of target-dependent _fpmath.h > files, but *also* add a generic _fpmath.h file for all other > targets, IMHO. > > > Maybe I am overestimating it. I just don't see the single _fpmath.h > > to rule them all with confidence like you do. I am not seeing the > > set of parameters in my head which makes this generic with > > some macros. > > > > I'd appreciate help on this. > > newlib/libc/include/machine/ieee.h does not help? > > Kind of like this: > > #if LDBL_MANT_DIG == 24 > union IEEEl2bits { > long double e; > # ifdef __IEEE_LITTLE_ENDIAN > struct { > __uint32_t manl :16; > __uint32_t manh :7; > __uint32_t exp :8; > __uint32_t sign :1; > } bits; > struct { > __uint32_t manl :16; > __uint32_t manh :7; > __uint32_t expsign :9; > } xbits; > # else > struct { > __uint32_t sign :1; > __uint32_t exp :8; > __uint32_t manh :7; > __uint32_t manl :16; > } bits; > struct { > __uint32_t expsign :9; > __uint32_t manh :7; > __uint32_t manl :16; > } xbits; > # endif > }; > # define LDBL_NBIT 0 > # define LDBL_IMPLICIT_NBIT > # define mask_nbit_l(u) ((void)0) > > # define LDBL_MANH_SIZE 7 > # define LDBL_MANL_SIZE 16 > > # define LDBL_TO_ARRAY32(u, a) do { \ > (a)[0] = (uint32_t)(u).bits.manl \ > | ((uint32_t)(u).bits.manh << LDBL_MANL_SIZE) \ > (a)[1] = 0; \ > } while(0) > #elif LDBL_MANT_DIG == 53 > union IEEEl2bits { > long double e; > # ifdef __IEEE_LITTLE_ENDIAN > struct { > __uint64_t manl :32; > __uint64_t manh :20; > __uint64_t exp :11; > __uint64_t sign :1; > } bits; > struct { > __uint64_t manl :32; > __uint64_t manh :20; > __uint64_t expsign :12; > } xbits; > # else > struct { > __uint64_t sign :1; > __uint64_t exp :11; > __uint64_t manh :20; > __uint64_t manl :32; > } bits; > struct { > __uint64_t expsign :12; > __uint64_t manh :20; > __uint64_t manl :32; > } xbits; > # endif > }; > # define LDBL_NBIT 0 > # define LDBL_IMPLICIT_NBIT > # define mask_nbit_l(u) ((void)0) > > # define LDBL_MANH_SIZE 20 > # define LDBL_MANL_SIZE 32 > > # define LDBL_TO_ARRAY32(u, a) do { \ > (a)[0] = (uint32_t)(u).bits.manl; \ > (a)[1] = (uint32_t)(u).bits.manh; \ > } while(0) > #elif LDBL_MANT_DIG == 64 > union IEEEl2bits { > long double e; > # ifdef __IEEE_LITTLE_ENDIAN > struct { > __uint64_t manl :32; > __uint64_t manh :32; > __uint64_t exp :15; > __uint64_t sign :1; > __uint64_t junk :16 > } bits; > struct { > __uint64_t man :64; > __uint64_t expsign :16; > __uint64_t junk :16 > } xbits; > # else > struct { > __uint64_t junk :16 > __uint64_t sign :1; > __uint64_t exp :15; > __uint64_t manh :32; > __uint64_t manl :32; > } bits; > struct { > __uint64_t junk :16 > __uint64_t expsign :16; > __uint64_t man :64; > } xbits; > # endif > }; > > # define LDBL_NBIT 0x80000000 > # define mask_nbit_l(u) ((u).bits.manh &= ~LDBL_NBIT) > > # define LDBL_MANH_SIZE 32 > # define LDBL_MANL_SIZE 32 > > # define LDBL_TO_ARRAY32(u, a) do { \ > (a)[0] = (uint32_t)(u).bits.manl; \ > (a)[1] = (uint32_t)(u).bits.manh; \ > } while(0) > #elif LDBL_MANT_DIG == 113 > union IEEEl2bits { > long double e; > # ifdef __IEEE_LITTLE_ENDIAN > struct { > __uint64_t manl :64; > __uint64_t manh :48; > __uint64_t exp :15; > __uint64_t sign :1; > } bits; > struct { > __uint64_t manl :64; > __uint64_t manh :48; > __uint64_t expsign :16; > } xbits; > # else > struct { > __uint64_t sign :1; > __uint64_t exp :15; > __uint64_t manh :48; > __uint64_t manl :64; > } bits; > struct { > __uint64_t expsign :16; > __uint64_t manh :48; > __uint64_t manl :64; > } xbits; > # endif > }; > > # define LDBL_NBIT 0 > # define LDBL_IMPLICIT_NBIT > # define mask_nbit_l(u) ((void)0) > > # define LDBL_MANH_SIZE 48 > # define LDBL_MANL_SIZE 64 > > # define LDBL_TO_ARRAY32(u, a) do { \ > (a)[0] = (uint32_t)(u).bits.manl; \ > (a)[1] = (uint32_t)((u).bits.manl >> 32); \ > (a)[2] = (uint32_t)(u).bits.manh; \ > (a)[3] = (uint32_t)((u).bits.manh >> 32); \ > } while(0) > #endif > > There's also a ___IEEE_BYTES_LITTLE_ENDIAN definition which I ignored > for now. Also, the LDBL_MANT_DIG == 64 is defined for x86-only and the > manl/manh fields for LDBL_MANT_DIG == 23 are faked on a 16 bit border > just to have a manl and a manh definition. > > I don't claim that it works OOTB with the above, but apart from > the LDBL_NBIT/mask_nbit_l values which differ for x86/x86_64 CPUs, > it should be a good start, I think. > > > > Jeff, ping? Your POV would be much appreciated here. > > > > Sorry for the late reply. I agree with your proposal Corinna. > > > +1 > > > > I also have come across there needs to be a way to pick between ld80 > > and ld128 headers and implementation files. FreeBSD has them in > > separate directories. Apparently their build system builds common > > plus an architecture specific _fpmath.h and a choice of ld80/ld128 > > which adds at least two other header files > > But then again, FreeBSD supports ARM and PowerPC, both of which come > with 64 bit long double. So, besides ld80/ld128, there's apparently a > generic implementation, too, to support non-ld80 and non-ld128 long > double, right? > > > Corinna > >