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Groups > comp.lang.c++ > #121949
| From | Michael S <already5chosen@yahoo.com> |
|---|---|
| Newsgroups | comp.lang.c++ |
| Subject | Re: a MSVC and glibc-compatible fmod() |
| Date | 2025-03-11 12:47 +0200 |
| Organization | A noiseless patient Spider |
| Message-ID | <20250311124706.0000200d@yahoo.com> (permalink) |
| References | (15 earlier) <20250310195128.000059ab@yahoo.com> <vqn9b5$1fisl$1@raubtier-asyl.eternal-september.org> <20250310203818.00007416@yahoo.com> <vqnlsl$1ia2q$1@raubtier-asyl.eternal-september.org> <vqnm0v$1ia2q$2@raubtier-asyl.eternal-september.org> |
On Mon, 10 Mar 2025 22:36:31 +0100
Bonita Montero <Bonita.Montero@gmail.com> wrote:
> Am 10.03.2025 um 22:34 schrieb Bonita Montero:
>
> > And for aribitrary exponets (0x1 to 0x7FE):
> >
> > fmodO: 9.29622
> > fmodM: 11.4518
>
> Sorry, the copy-buffer wasn't refreshed with the new results:
>
> fmodO: 40.4702
> fmodM: 40.1652
Let's establish common measurement methodology.
Here is my throughput test bench (I have different test bench for
correctness tests and plan to build yet different one for latency
tests).
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cfenv>
#include <vector>
#include <random>
#include <chrono>
extern "C" double my_fmod(double x, double y);
int main(void)
{
const int VEC_LEN = 100000;
const int N_IT = 31;
std::vector<double> xy(VEC_LEN*2);
std::vector<double> res(VEC_LEN);
std::vector<double> ref(VEC_LEN);
std::mt19937_64 rndGen;
for (int rep = 0; rep < 2; ++rep) {
if (rep == 0) {
const uint64_t EXP_MASK = 2047ull << 52;
for (int i = 0; i < VEC_LEN*2; ++i) {
uint64_t u = rndGen();
uint64_t exp = 1023;
if (i % 2 == 0) { // x
uint64_t exp0 = (u >> 52) & 2047;
exp += exp0 % 52;
}
u = (u & ~EXP_MASK) | (exp << 52);
double d;
memcpy(&d, &u, sizeof(d));
xy[i] = d;
}
} else {
for (int i = 0; i < VEC_LEN*2; ++i) {
uint64_t u = rndGen();
double d;
memcpy(&d, &u, sizeof(d));
xy[i] = d;
}
}
auto t00 = std::chrono::steady_clock::now();
const double* pXY = xy.data();
double* pRef = ref.data();
double* pRes = res.data();
std::vector<int64_t> tref(N_IT);
std::vector<int64_t> tres(N_IT);
for (int it = 0; it < N_IT; ++it) {
auto t0 = std::chrono::steady_clock::now();
for (int i = 0; i < VEC_LEN; ++i)
pRef[i] = fmod(pXY[i*2+0], pXY[i*2+1]);
auto t1 = std::chrono::steady_clock::now();
for (int i = 0; i < VEC_LEN; ++i)
pRes[i] = my_fmod(pXY[i*2+0], pXY[i*2+1]);
auto t2 = std::chrono::steady_clock::now();
tref[it] =
std::chrono::duration_cast<std::chrono::nanoseconds>(t1 -
t0).count(); tres[it] =
std::chrono::duration_cast<std::chrono::nanoseconds>(t2 -
t1).count();
for (int i = 0; i < VEC_LEN; ++i) {
if (pRef[i] != pRes[i]) {
if (!std::isnan(pRef[i]) || !std::isnan(pRes[i])) {
printf(
"Mismatch. fmod(%.17e, %.17e).\n"
"ref %.17e\n"
"my %.17e\n"
,xy[i*2+0]
,xy[i*2+1]
,ref[i]
,res[i]
);
return 1;
}
}
}
}
auto t11 = std::chrono::steady_clock::now();
int64_t dt =
std::chrono::duration_cast<std::chrono::nanoseconds>(t11 -
t00).count();
std::nth_element(tref.begin(), tref.begin()+N_IT/2, tref.end());
std::nth_element(tres.begin(), tres.begin()+N_IT/2, tres.end());
printf("fmod %6.2f nsec. my_fmod %6.2f nsec. Test time %7.3f msec\n"
,double(tref[N_IT/2]) / VEC_LEN
,double(tres[N_IT/2]) / VEC_LEN
,double(dt)*1e-6
);
}
return 0;
}
What happens when you take this code 'as is' compile it and run
it in each of 3 environments with following options:
MSVC:
cl -nologo -O2 -W4 -arch:AVX2 -std:c++20 -MD -EHsc
gcc/clang under msys2:
C:
gcc -O2 -Wall -std=c17 -march=haswell
or
clang -O2 -Wall -std=c17 -march=haswell
C++:
g++ -O2 -Wall -std=c++20 -march=haswell
or
clang++ -O2 -Wall -std=c17 -march=haswell
gcc/clang under msys2:
The same as above with addition of -lm
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a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-24 11:48 +0100
Re: a MSVC and glibc-compatible fmod() Muttley@DastardlyHQ.org - 2025-02-24 12:00 +0000
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-24 13:48 +0100
Re: a MSVC and glibc-compatible fmod() Muttley@DastardlyHQ.org - 2025-02-24 13:09 +0000
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-24 14:22 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-24 17:13 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-24 16:19 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-24 17:52 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-25 09:09 +0100
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-25 16:17 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-25 17:26 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-25 16:45 +0100
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-25 16:57 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-25 19:17 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-25 18:58 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-26 00:36 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-26 04:15 +0100
Re: a MSVC and glibc-compatible fmod() Muttley@DastardlyHQ.org - 2025-02-26 08:16 +0000
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-26 14:27 +0200
Re: a MSVC and glibc-compatible fmod() Muttley@DastardlyHQ.org - 2025-02-26 14:39 +0000
FP_CONTRACT was : a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-28 16:28 +0200
Re: FP_CONTRACT was : a MSVC and glibc-compatible fmod() Tim Rentsch <tr.17687@z991.linuxsc.com> - 2025-03-01 08:35 -0800
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-24 16:22 +0200
Re: a MSVC and glibc-compatible fmod() Muttley@DastardlyHQ.org - 2025-02-24 15:10 +0000
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-24 17:33 +0200
Re: a MSVC and glibc-compatible fmod() Muttley@DastardlyHQ.org - 2025-02-24 16:48 +0000
Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-02-24 22:21 +0000
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-25 07:37 +0100
Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-02-25 23:03 +0000
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-26 02:00 +0200
Re: a MSVC and glibc-compatible fmod() Wuns Haerst <Wuns.Haerst@wurstfabrik.at> - 2025-02-26 04:01 +0100
Re: a MSVC and glibc-compatible fmod() Muttley@DastardlyHQ.org - 2025-02-25 08:24 +0000
Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-02-27 21:16 +0000
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-28 07:59 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-28 12:35 +0200
Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-02-28 18:12 +0000
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-28 19:23 +0100
Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-02-28 18:30 +0000
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-28 19:31 +0100
Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-02-28 19:47 +0000
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-28 20:49 +0100
Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-03-01 14:37 +0000
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-01 16:58 +0100
Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-03-01 17:11 +0000
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-01 21:02 +0100
Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-03-01 20:32 +0000
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-01 21:37 +0100
Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-03-01 20:45 +0000
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 09:40 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-01 22:55 +0200
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 18:54 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 17:59 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 15:41 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 17:10 +0100
Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-03-02 16:22 +0000
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 17:26 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 19:07 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 18:09 +0100
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 18:11 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 19:52 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 18:55 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 20:09 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 19:14 +0100
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 19:57 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 22:58 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-03 12:52 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-03 18:10 +0200
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-03 23:55 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-07 09:51 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-03 18:20 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-03 17:30 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-03 19:27 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-03 18:39 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-03 02:01 +0200
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 19:37 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 18:41 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 20:00 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 19:01 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 01:31 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 07:41 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 11:08 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 10:31 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 11:46 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 10:54 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 12:09 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 11:21 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 14:09 +0200
Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-03-09 15:26 +0000
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 17:02 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 19:55 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 19:10 +0100
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 19:27 +0100
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 17:23 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 20:04 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 19:11 +0100
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 20:11 +0100
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 07:24 +0100
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 10:46 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-10 14:26 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 13:45 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-10 16:33 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 15:46 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-10 16:59 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 16:11 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-10 17:43 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 17:13 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-10 19:51 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 19:00 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-10 20:38 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 22:34 +0100
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 22:36 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-11 12:47 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 23:52 +0100
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 23:57 +0100
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-11 09:34 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-11 12:29 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-11 12:12 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-11 13:34 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-11 13:10 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-11 14:55 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-11 14:08 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-11 15:46 +0200
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-11 13:51 +0200
Re: a MSVC and glibc-compatible fmod() James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-03-11 14:21 -0400
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-11 20:28 +0200
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-16 13:48 +0200
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-10 13:17 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 12:53 +0100
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 12:54 +0100
Re: a MSVC and glibc-compatible fmod() wij <wyniijj5@gmail.com> - 2025-03-09 18:51 +0800
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 12:56 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 14:23 +0200
Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 13:39 +0100
Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 14:56 +0200
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