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2020-03-24math: add x86_64 remquolAlexander Monakov-0/+32
2020-03-24math: move x87-family fmod functions to C with inline asmAlexander Monakov-44/+38
2020-03-24math: move x87-family remainder functions to C with inline asmAlexander Monakov-50/+42
2020-03-24math: move x87-family rint functions to C with inline asmAlexander Monakov-24/+28
2020-03-24math: move x87-family lrint functions to C with inline asmAlexander Monakov-60/+64
2020-03-24math: move x86_64 (l)lrint(f) functions to C with inline asmAlexander Monakov-20/+32
2020-03-24math: move i386 sqrt to C with inline asmAlexander Monakov-21/+15
2020-03-24math: move i386 sqrtf to C with inline asmAlexander Monakov-7/+12
2020-03-24math: move trivial x86-family sqrt functions to C with inline asmAlexander Monakov-18/+28
2020-03-24math: move x87-family fabs functions to C with inline asmAlexander Monakov-24/+28
2020-03-24math: move x86_64 fabs, fabsf to C with inline asmAlexander Monakov-16/+20
2020-02-21math: fix sinh overflows in non-nearest roundingSzabolcs Nagy-8/+10
The final rounding operation should be done with the correct sign otherwise huge results may incorrectly get rounded to or away from infinity in upward or downward rounding modes. This affected sinh and sinhf which set the sign on the result after a potentially overflowing mul. There may be other non-nearest rounding issues, but this was a known long standing issue with large ulp error (depending on how ulp is defined near infinity). The fix should have no effect on sinh and sinhf performance but may have a tiny effect on cosh and coshf.
2020-02-21math: fix __rem_pio2 in non-nearest rounding modesSzabolcs Nagy-3/+41
Handle when after reduction |y| > pi/4+tiny. This happens in directed rounding modes because the fast round to int code does not give the nearest integer. In such cases the reduction may not be symmetric between x and -x so e.g. cos(x)==cos(-x) may not hold (but polynomial evaluation is not symmetric either with directed rounding so fixing that would require more changes with bigger performance impact). The fix only adds two predictable branches in nearest rounding mode, simple ubenchmark does not show relevant performance regression in nearest rounding mode. The code could be improved: e.g reducing the medium size threshold such that two step reduction is enough instead of three, and the single precision case can avoid the issue by doing the round to int differently, but this fix was kept minimal.
2020-02-06remove i386 asm for single and double precision exp-family functionsRich Felker-62/+3
these did not truncate excess precision in the return value. fixing them looks like considerable work, and the current C code seems to outperform them significantly anyway. long double functions are left in place because they are not subject to excess precision issues and probably better than the C code.
2020-02-06rename i386 exp.s to exp_ld.sRich Felker-0/+1
this commit is for the sake of reviewable history.
2020-02-06fix excess precision in return value of i386 log-family functionsRich Felker-0/+20
2020-02-06fix excess precision in return value of i386 acos[f] and asin[f]Rich Felker-42/+75
analogous to commit 1c9afd69051a64cf085c6fb3674a444ff9a43857 for atan[2][f].
2020-02-06fix excess precision in return value of i386 atan[2][f]Rich Felker-2/+8
for functions implemented in C, this is a requirement of C11 (F.6); strictly speaking that text does not apply to standard library functions, but it seems to be intended to apply to them, and C2x is expected to make it a requirement. failure to drop excess precision is particularly bad for inverse trig functions, where a value with excess precision can be outside the range of the function (entire range, or range for a particular subdomain), breaking reasonable invariants a caller may expect.
2020-01-27math/x32: correct lrintl.s for 32-bit longAlexander Monakov-2/+2
2019-11-05ppc: add configure check for older compilers erroring on 'd' constraintrofl0r-2/+2
2019-10-14mips: add single-instruction math functionsinfo@mobile-stream.com-0/+64
SQRT.fmt exists on MIPS II+ (float), MIPS III+ (double). ABS.fmt exists on MIPS I+ but only cores with ABS2008 flag in FCSR implement the required behaviour.
2019-10-13math: fix signed int left shift ub in sqrtSzabolcs Nagy-4/+2
Both sqrt and sqrtf shifted the signed exponent as signed int to adjust the bit representation of the result. There are signed right shifts too in the code but those are implementation defined and are expected to compile to arithmetic shift on supported compilers and targets.
2019-09-27math: optimize lrint on 32bit targetsSzabolcs Nagy-1/+27
lrint in (LONG_MAX, 1/DBL_EPSILON) and in (-1/DBL_EPSILON, LONG_MIN) is not trivial: rounding to int may be inexact, but the conversion to int may overflow and then the inexact flag must not be raised. (the overflow threshold is rounding mode dependent). this matters on 32bit targets (without single instruction lrint or rint), so the common case (when there is no overflow) is optimized by inlining the lrint logic, otherwise the old code is kept as a fallback. on my laptop an i486 lrint call is asm:10ns, old c:30ns, new c:21ns on a smaller arm core: old c:71ns, new c:34ns on a bigger arm core: old c:27ns, new c:19ns
2019-08-05fix build regression in i386 asm for atan2, atan2fRich Felker-2/+2
commit f3ed8bfe8a82af1870ddc8696ed4cc1d5aa6b441 inadvertently removed labels that were still needed.
2019-08-05fix x87 stack imbalance in corner cases of i386 math asmRich Felker-44/+14
commit 31c5fb80b9eae86f801be4f46025bc6532a554c5 introduced underflow code paths for the i386 math asm, along with checks on the fpu status word to skip the underflow-generation instructions if the underflow flag was already raised. unfortunately, at least one such path, in log1p, returned with 2 items on the x87 stack rather than just 1 item for the return value. this is a violation of the ABI's calling convention, and could cause subsequent floating point code to produce NANs due to x87 stack overflow. if floating point results are used in flow control, this can lead to runaway wrong code execution. rather than reviewing each "underflow already raised" code path for correctness, remove them all. they're likely slower than just performing the underflow code unconditionally, and significantly more complex. all of this code should be ripped out and replaced by C source files with inline asm. doing so would preclude this kind of error by having the compiler perform all x87 stack register allocation and stack manipulation, and would produce comparable or better code. however such a change is a much larger project.
2019-06-14add riscv64 architecture supportRich Felker-0/+180
Author: Alex Suykov <alex.suykov@gmail.com> Author: Aric Belsito <lluixhi@gmail.com> Author: Drew DeVault <sir@cmpwn.com> Author: Michael Clark <mjc@sifive.com> Author: Michael Forney <mforney@mforney.org> Author: Stefan O'Rear <sorear2@gmail.com> This port has involved the work of many people over several years. I have tried to ensure that everyone with substantial contributions has been credited above; if any omissions are found they will be noted later in an update to the authors/contributors list in the COPYRIGHT file. The version committed here comes from the riscv/riscv-musl repo's commit 3fe7e2c75df78eef42dcdc352a55757729f451e2, with minor changes by me for issues found during final review: - a_ll/a_sc atomics are removed (according to the ISA spec, lr/sc are not safe to use in separate inline asm fragments) - a_cas[_p] is fixed to be a memory barrier - the call from the _start assembly into the C part of crt1/ldso is changed to allow for the possibility that the linker does not place them nearby each other. - DTP_OFFSET is defined correctly so that local-dynamic TLS works - reloc.h LDSO_ARCH logic is simplified and made explicit. - unused, non-functional crti/n asm files are removed. - an empty .sdata section is added to crt1 so that the __global_pointer reference is resolvable. - indentation style errors in some asm files are fixed.
2019-04-17math: new powSzabolcs Nagy-303/+520
from https://github.com/ARM-software/optimized-routines, commit 04884bd04eac4b251da4026900010ea7d8850edc The underflow exception is signaled if the result is in the subnormal range even if the result is exact. code size change: +3421 bytes. benchmark on x86_64 before, after, speedup: -Os: pow rthruput: 102.96 ns/call 33.38 ns/call 3.08x pow latency: 144.37 ns/call 54.75 ns/call 2.64x -O3: pow rthruput: 98.91 ns/call 32.79 ns/call 3.02x pow latency: 138.74 ns/call 53.78 ns/call 2.58x
2019-04-17math: new exp and exp2Szabolcs Nagy-480/+434
from https://github.com/ARM-software/optimized-routines, commit 04884bd04eac4b251da4026900010ea7d8850edc TOINT_INTRINSICS and EXP_USE_TOINT_NARROW cases are unused. The underflow exception is signaled if the result is in the subnormal range even if the result is exact (e.g. exp2(-1023.0)). code size change: -1672 bytes. benchmark on x86_64 before, after, speedup: -Os: exp rthruput: 12.73 ns/call 6.68 ns/call 1.91x exp latency: 45.78 ns/call 21.79 ns/call 2.1x exp2 rthruput: 6.35 ns/call 5.26 ns/call 1.21x exp2 latency: 26.00 ns/call 16.58 ns/call 1.57x -O3: exp rthruput: 12.75 ns/call 6.73 ns/call 1.89x exp latency: 45.91 ns/call 21.80 ns/call 2.11x exp2 rthruput: 6.47 ns/call 5.40 ns/call 1.2x exp2 latency: 26.03 ns/call 16.54 ns/call 1.57x
2019-04-17math: new log2Szabolcs Nagy-106/+335
from https://github.com/ARM-software/optimized-routines, commit 04884bd04eac4b251da4026900010ea7d8850edc code size change: +2458 bytes (+1524 bytes with fma). benchmark on x86_64 before, after, speedup: -Os: log2 rthruput: 16.08 ns/call 10.49 ns/call 1.53x log2 latency: 44.54 ns/call 25.55 ns/call 1.74x -O3: log2 rthruput: 15.92 ns/call 10.11 ns/call 1.58x log2 latency: 44.66 ns/call 26.16 ns/call 1.71x
2019-04-17math: new logSzabolcs Nagy-104/+454
from https://github.com/ARM-software/optimized-routines, commit 04884bd04eac4b251da4026900010ea7d8850edc Assume __FP_FAST_FMA implies __builtin_fma is inlined as a single instruction. code size change: +4588 bytes (+2540 bytes with fma). benchmark on x86_64 before, after, speedup: -Os: log rthruput: 12.61 ns/call 7.95 ns/call 1.59x log latency: 41.64 ns/call 23.38 ns/call 1.78x -O3: log rthruput: 12.51 ns/call 7.75 ns/call 1.61x log latency: 41.82 ns/call 23.55 ns/call 1.78x
2019-04-17math: new powfSzabolcs Nagy-240/+226
from https://github.com/ARM-software/optimized-routines, commit 04884bd04eac4b251da4026900010ea7d8850edc POWF_SCALE != 1.0 case only matters if TOINT_INTRINSICS is set, which is currently not supported for any target. SNaN is not supported, it would require an issignalingf implementation. code size change: -816 bytes. benchmark on x86_64 before, after, speedup: -Os: powf rthruput: 95.14 ns/call 20.04 ns/call 4.75x powf latency: 137.00 ns/call 34.98 ns/call 3.92x -O3: powf rthruput: 92.48 ns/call 13.67 ns/call 6.77x powf latency: 131.11 ns/call 35.15 ns/call 3.73x
2019-04-17math: new exp2f and expfSzabolcs Nagy-179/+177
from https://github.com/ARM-software/optimized-routines, commit 04884bd04eac4b251da4026900010ea7d8850edc In expf TOINT_INTRINSICS is kept, but is unused, it would require support for __builtin_round and __builtin_lround as single instruction. code size change: +94 bytes. benchmark on x86_64 before, after, speedup: -Os: expf rthruput: 9.19 ns/call 8.11 ns/call 1.13x expf latency: 34.19 ns/call 18.77 ns/call 1.82x exp2f rthruput: 5.59 ns/call 6.52 ns/call 0.86x exp2f latency: 17.93 ns/call 16.70 ns/call 1.07x -O3: expf rthruput: 9.12 ns/call 4.92 ns/call 1.85x expf latency: 34.44 ns/call 18.99 ns/call 1.81x exp2f rthruput: 5.58 ns/call 4.49 ns/call 1.24x exp2f latency: 17.95 ns/call 16.94 ns/call 1.06x
2019-04-17math: new log2fSzabolcs Nagy-58/+108
from https://github.com/ARM-software/optimized-routines, commit 04884bd04eac4b251da4026900010ea7d8850edc code size change: +177 bytes. benchmark on x86_64 before, after, speedup: -Os: log2f rthruput: 11.38 ns/call 5.99 ns/call 1.9x log2f latency: 35.01 ns/call 22.57 ns/call 1.55x -O3: log2f rthruput: 10.82 ns/call 5.58 ns/call 1.94x log2f latency: 35.13 ns/call 21.04 ns/call 1.67x
2019-04-17math: new logfSzabolcs Nagy-54/+109
from https://github.com/ARM-software/optimized-routines, commit 04884bd04eac4b251da4026900010ea7d8850edc, with minor changes to better fit into musl. code size change: +289 bytes. benchmark on x86_64 before, after, speedup: -Os: logf rthruput: 8.40 ns/call 6.14 ns/call 1.37x logf latency: 31.79 ns/call 24.33 ns/call 1.31x -O3: logf rthruput: 8.43 ns/call 5.58 ns/call 1.51x logf latency: 32.04 ns/call 20.88 ns/call 1.53x
2019-04-17math: add double precision error handling functionsSzabolcs Nagy-0/+30
2019-04-17math: add single precision error handling functionsSzabolcs Nagy-0/+30
These are supposed to be used in tail call positions when handling special cases in new code. (fp exceptions may be raised "naturally" by the common code path if special casing is more effort.) This implements the error handling apis used in https://github.com/ARM-software/optimized-routines without errno setting.
2019-04-03fix unintended global symbols in atanl.cDan Gohman-3/+3
Mark atanhi, atanlo, and aT in atanl.c as static, as they're not intended to be part of the public API. These are already static in the LDBL_MANT_DIG == 64 code, so this patch is just making the LDBL_MANT_DIG == 113 code do the same thing.
2018-10-15x86_64: add single instruction fmaSzabolcs Nagy-0/+92
fma is only available on recent x86_64 cpus and it is much faster than a software fma, so this should be done with a runtime check, however that requires more changes, this patch just adds the code so it can be tested when musl is compiled with -mfma or -mfma4.
2018-10-15arm: add single instruction fmaSzabolcs Nagy-0/+30
vfma is available in the vfpv4 fpu and above, the ACLE standard feature test for double precision hardware fma support is __ARM_FEATURE_FMA && __ARM_FP&8 we need further checks to work around clang bugs (fixed in clang >=7.0) && !__SOFTFP__ because __ARM_FP is defined even with -mfloat-abi=soft && !BROKEN_VFP_ASM to disable the single precision code when inline asm handling is broken. For runtime selection the HWCAP_ARM_VFPv4 hwcap flag can be used, but that requires further work.
2018-10-15powerpc: add single instruction fabs, fabsf, fma, fmaf, sqrt, sqrtfSzabolcs Nagy-0/+90
These are only available on hard float target and sqrt is not available in the base ISA, so further check is used.
2018-10-15s390x: add single instruction fma and fmafSzabolcs Nagy-0/+14
These are available in the s390x baseline isa -march=z900.
2018-09-12reduce spurious inclusion of libc.hRich Felker-9/+0
libc.h was intended to be a header for access to global libc state and related interfaces, but ended up included all over the place because it was the way to get the weak_alias macro. most of the inclusions removed here are places where weak_alias was needed. a few were recently introduced for hidden. some go all the way back to when libc.h defined CANCELPT_BEGIN and _END, and all (wrongly implemented) cancellation points had to include it. remaining spurious users are mostly callers of the LOCK/UNLOCK macros and files that use the LFS64 macro to define the awful *64 aliases. in a few places, new inclusion of libc.h is added because several internal headers no longer implicitly include libc.h. declarations for __lockfile and __unlockfile are moved from libc.h to stdio_impl.h so that the latter does not need libc.h. putting them in libc.h made no sense at all, since the macros in stdio_impl.h are needed to use them correctly anyway.
2018-09-12apply hidden visibility to various remaining internal interfacesRich Felker-0/+2
2018-09-12apply hidden visibility to internal math functionsRich Felker-2/+2
this makes significant differences to codegen on archs with an expensive PLT-calling ABI; on i386 and gcc 7.3 for example, the sin and sinf functions no longer touch call-saved registers or the stack except for pushing outgoing arguments. performance is likely improved too, but no measurements were taken.
2018-09-12move lgamma-related internal declarations to libm.hRich Felker-12/+3
2018-06-14add support for m68k 80-bit long double variantRich Felker-2/+10
since x86 and m68k are the only archs with 80-bit long double and each has mandatory endianness, select the variant via endianness. differences are minor: apparently just byte order and representation of infinities. the m68k format is not well-documented anywhere I could find, so if other differences are found they may require additional changes later.
2018-04-02fix fmaf wrong resultSzabolcs Nagy-1/+1
if double precision r=x*y+z is not a half way case between two single precision floats or it is an exact result then fmaf returns (float)r. however the exactness check was wrong when |x*y| < |z| and could cause incorrectly rounded result in nearest rounding mode when r is a half way case. fmaf(-0x1.26524ep-54, -0x1.cb7868p+11, 0x1.d10f5ep-29) was incorrectly rounded up to 0x1.d117ap-29 instead of 0x1.d1179ep-29. (exact result is 0x1.d1179efffffffecp-29, r is 0x1.d1179fp-29)
2017-10-13math: rewrite fma with mostly int arithmeticsSzabolcs Nagy-431/+154
the freebsd fma code failed to raise underflow exception in some cases in nearest rounding mode (affects fmal too) e.g. fma(-0x1p-1000, 0x1.000001p-74, 0x1p-1022) and the inexact exception may be raised spuriously since the fenv is not saved/restored around the exact multiplication algorithm (affects x86 fma too). another issue is that the underflow behaviour when the rounded result is the minimal normal number is target dependent, ieee754 allows two ways to raise underflow for inexact results: raise if the result before rounding is in the subnormal range (e.g. aarch64, arm, powerpc) or if the result after rounding with infinite exponent range is in the subnormal range (e.g. x86, mips, sh). to avoid all these issues the algorithm was rewritten with mostly int arithmetics and float arithmetics is only used to get correct rounding and raise exceptions according to the behaviour of the target without any fenv.h dependency. it also unifies x86 and non-x86 fma. fmaf is not affected, fmal need to be fixed too. this algorithm depends on a_clz_64 and it required a few spurious instructions to make sure underflow exception is raised in a particular corner case. (normally FORCE_EVAL(tiny*tiny) would be used for this, but on i386 gcc is broken if the expression is constant https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57245 and there is no easy portable fix for the macro.)
2017-06-23powerpc64: add single-instruction math functionsRich Felker-0/+290
while the official elfv2 abi for "powerpc64le" sets power8 as the baseline isa, we use it for both little and big endian powerpc64 targets and need to maintain compatibility with pre-power8 models. the instructions for sqrt, fabs, and fma are in the baseline isa; support for the rest is conditional via predefined isa-level macros. patch by David Edelsohn.
2017-06-23s390x: add single-instruction math functionsRich Felker-0/+360
these were introduced in z196 and not available in the baseline (z900) ISA level. use __HTM__ as an alternate indicator for ISA level, since gcc did not define __ARCH__ until 7.x. patch by David Edelsohn.
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