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gcc/libgcc/config/i386/64/t-softfp

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libgcc _BitInt support [PR102989] This patch adds the library helpers for multiplication, division + modulo and casts from and to floating point (both binary and decimal). As described in the intro, the first step is try to reduce further the passed in precision by skipping over most significant limbs with just zeros or sign bit copies. For multiplication and division I've implemented a simple algorithm, using something smarter like Karatsuba or Toom N-Way might be faster for very large _BitInts (which we don't support right now anyway), but could mean more code in libgcc, which maybe isn't what people are willing to accept. For the to/from floating point conversions the patch uses soft-fp, because it already has tons of handy macros which can be used for that. In theory it could be implemented using {,unsigned} long long or {,unsigned} __int128 to/from floating point conversions with some frexp before/after, but at that point we already need to force it into integer registers and analyze it anyway. Plus, for 32-bit arches there is no __int128 that could be used for XF/TF mode stuff. I know that soft-fp is owned by glibc and I think the op-common.h change should be propagated there, but the bitint stuff is really GCC specific and IMHO doesn't belong into the glibc copy. 2023-09-06 Jakub Jelinek <jakub@redhat.com> PR c/102989 libgcc/ * config/aarch64/t-softfp (softfp_extras): Use += rather than :=. * config/i386/64/t-softfp (softfp_extras): Likewise. * config/i386/libgcc-glibc.ver (GCC_14.0.0): Export _BitInt support routines. * config/i386/t-softfp (softfp_extras): Add fixxfbitint and bf, hf and xf mode floatbitint. (CFLAGS-floatbitintbf.c, CFLAGS-floatbitinthf.c): Add -msse2. * config/riscv/t-softfp32 (softfp_extras): Use += rather than :=. * config/rs6000/t-e500v1-fp (softfp_extras): Likewise. * config/rs6000/t-e500v2-fp (softfp_extras): Likewise. * config/t-softfp (softfp_floatbitint_funcs): New. (softfp_bid_list): New. (softfp_func_list): Add sf and df mode from and to _BitInt libcalls. (softfp_bid_file_list): New. (LIB2ADD_ST): Add $(softfp_bid_file_list). * config/t-softfp-sfdftf (softfp_extras): Add fixtfbitint and floatbitinttf. * config/t-softfp-tf (softfp_extras): Likewise. * libgcc2.c (bitint_reduce_prec): New inline function. (BITINT_INC, BITINT_END): Define. (bitint_mul_1, bitint_addmul_1): New helper functions. (__mulbitint3): New function. (bitint_negate, bitint_submul_1): New helper functions. (__divmodbitint4): New function. * libgcc2.h (LIBGCC2_UNITS_PER_WORD): When building _BitInt support libcalls, redefine depending on __LIBGCC_BITINT_LIMB_WIDTH__. (__mulbitint3, __divmodbitint4): Declare. * libgcc-std.ver.in (GCC_14.0.0): Export _BitInt support routines. * Makefile.in (lib2funcs): Add _mulbitint3. (LIB2_DIVMOD_FUNCS): Add _divmodbitint4. * soft-fp/bitint.h: New file. * soft-fp/fixdfbitint.c: New file. * soft-fp/fixsfbitint.c: New file. * soft-fp/fixtfbitint.c: New file. * soft-fp/fixxfbitint.c: New file. * soft-fp/floatbitintbf.c: New file. * soft-fp/floatbitintdf.c: New file. * soft-fp/floatbitinthf.c: New file. * soft-fp/floatbitintsf.c: New file. * soft-fp/floatbitinttf.c: New file. * soft-fp/floatbitintxf.c: New file. * soft-fp/op-common.h (_FP_FROM_INT): Add support for rsize up to 4 * _FP_W_TYPE_SIZE rather than just 2 * _FP_W_TYPE_SIZE. * soft-fp/bitintpow10.c: New file. * soft-fp/fixsdbitint.c: New file. * soft-fp/fixddbitint.c: New file. * soft-fp/fixtdbitint.c: New file. * soft-fp/floatbitintsd.c: New file. * soft-fp/floatbitintdd.c: New file. * soft-fp/floatbitinttd.c: New file.
2023-09-06 17:33:05 +02:00
softfp_extras += fixhfti fixunshfti floattihf floatuntihf \
libgcc, i386: Add __fix{,uns}bfti and __float{,un}tibf [PR107703] While DI <-> BF conversions can be handled (and are) through DI <-> XF <-> BF and for narrower integral modes even sometimes through DF or SF, because XFmode has 64-bit mantissa and so all the DImode values are exactly representable in XFmode. That is not the case for TImode, and while e.g. the HF -> TI conversions are IMHO useless in libgcc, because HFmode has -65504.0f16, 65504.0f16 range, all the integers will be already representable in SImode (or even HImode for unsigned) and so I think HF -> DI -> TI conversions are faster and valid, BFmode has roughly the same range as SFmode and so we absolutely need the TI -> BF conversions to avoid double rounding. As for BF -> TI conversions, they can be either also implemented in libgcc, or they can be implemented (as done in this commit) as BF -> SF -> TI conversions with the same code generation used elsewhere, just doing the 16-bit left shift of the bits - I think we don't need to handle sNaNs during the BF -> SF part because SF -> TI (which is already a libcall too) will handle that too. The BF -> SF -> TI path avoids wasting 32: 0000000000015e10 321 FUNC GLOBAL DEFAULT 13 __fixbfti@@GCC_13.0.0 89: 0000000000015f60 299 FUNC GLOBAL DEFAULT 13 __fixunsbfti@@GCC_13.0.0 2023-03-10 Jakub Jelinek <jakub@redhat.com> PR target/107703 * optabs.cc (expand_fix): For conversions from BFmode to integral, use shifts to convert it to SFmode first and then convert SFmode to integral. * soft-fp/floattibf.c: New file. * soft-fp/floatuntibf.c: New file. * config/i386/libgcc-glibc.ver: Export __float{,un}tibf @ GCC_13.0.0. * config/i386/64/t-softfp (softfp_extras): Add floattibf and floatuntibf. (CFLAGS-floattibf.c, CFLAGS-floatunstibf.c): Add -msse2.
2023-03-10 20:39:54 +01:00
floattibf floatuntibf
Explicitly add -msse2 to compile HF related libgcc source file. For 32-bit libgcc configure w/o sse2, there's would be an error since GCC only support _Float16 under sse2. Explicitly add -msse2 for those HF related libgcc functions, so users can still link them w/ the upper configuration. libgcc/ChangeLog: * Makefile.in: Adjust to support specific CFLAGS for each libgcc source file. * config/i386/64/t-softfp: Explicitly add -msse2 for HF related libgcc source files. * config/i386/t-softfp: Ditto. * config/i386/_divhc3.c: New file. * config/i386/_mulhc3.c: New file.
2021-09-03 13:06:57 +08:00
CFLAGS-fixhfti.c += -msse2
CFLAGS-fixunshfti.c += -msse2
CFLAGS-floattihf.c += -msse2
CFLAGS-floatunstihf.c += -msse2
libgcc, i386: Add __fix{,uns}bfti and __float{,un}tibf [PR107703] While DI <-> BF conversions can be handled (and are) through DI <-> XF <-> BF and for narrower integral modes even sometimes through DF or SF, because XFmode has 64-bit mantissa and so all the DImode values are exactly representable in XFmode. That is not the case for TImode, and while e.g. the HF -> TI conversions are IMHO useless in libgcc, because HFmode has -65504.0f16, 65504.0f16 range, all the integers will be already representable in SImode (or even HImode for unsigned) and so I think HF -> DI -> TI conversions are faster and valid, BFmode has roughly the same range as SFmode and so we absolutely need the TI -> BF conversions to avoid double rounding. As for BF -> TI conversions, they can be either also implemented in libgcc, or they can be implemented (as done in this commit) as BF -> SF -> TI conversions with the same code generation used elsewhere, just doing the 16-bit left shift of the bits - I think we don't need to handle sNaNs during the BF -> SF part because SF -> TI (which is already a libcall too) will handle that too. The BF -> SF -> TI path avoids wasting 32: 0000000000015e10 321 FUNC GLOBAL DEFAULT 13 __fixbfti@@GCC_13.0.0 89: 0000000000015f60 299 FUNC GLOBAL DEFAULT 13 __fixunsbfti@@GCC_13.0.0 2023-03-10 Jakub Jelinek <jakub@redhat.com> PR target/107703 * optabs.cc (expand_fix): For conversions from BFmode to integral, use shifts to convert it to SFmode first and then convert SFmode to integral. * soft-fp/floattibf.c: New file. * soft-fp/floatuntibf.c: New file. * config/i386/libgcc-glibc.ver: Export __float{,un}tibf @ GCC_13.0.0. * config/i386/64/t-softfp (softfp_extras): Add floattibf and floatuntibf. (CFLAGS-floattibf.c, CFLAGS-floatunstibf.c): Add -msse2.
2023-03-10 20:39:54 +01:00
CFLAGS-floattibf.c += -msse2
CFLAGS-floatunstibf.c += -msse2
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