Talk about a "blast form the past!" This Bug is now over 10 years old. But at least somebody is still working on it and it was not just quietly dropped. I can respect that.
My original recommendation stands: At least use long double for the calcuations where available. Regards, Arno On Sun, Nov 22, 2020 at 00:21:50 CET, Peter Maydell wrote: > For 5.1 (commits 1f18a1e6ab8368a4, 5eebc49d2d0aa5fc7e, > 5ef396e2ba865f34a, eca30647fc078f4) we reimplemented FPATAN, FYL2X, > FYL2XP1, FPREM, FPREM1, F2XM1 to do proper 80-bit precision operations. > However the trig operations FPTAN, FSINCOS, FSIN, FCOS are still > implemented as naive "convert to host double and use host C library > functions". > > -- > You received this bug notification because you are subscribed to the bug > report. > https://bugs.launchpad.net/bugs/645662 > > Title: > QEMU x87 emulation of trig and other complex ops is only at 64-bit > precision, not 80-bit > > Status in QEMU: > Confirmed > > Bug description: > When doing the regression tests for Python 3.1.2 with Qemu 0.12.5, (Linux > version 2.6.26-2-686 (Debian 2.6.26-25lenny1)), > gcc (Debian 4.3.2-1.1) 4.3.2, Python compiled from sources within qemu, > 3 math tests fail, apparently because the floating point unit is buggy. > Qmeu was compiled from original sources > on Debian Lenny with kernel 2.6.34.6 from kernel.org, gcc (Debian > 4.3.2-1.1) 4.3. > > Regression testing errors: > > test_cmath > test test_cmath failed -- Traceback (most recent call last): > File "/root/tools/python3/Python-3.1.2/Lib/test/test_cmath.py", line 364, > in > self.fail(error_message) > AssertionError: acos0034: acos(complex(-1.0000000000000002, 0.0)) > Expected: complex(3.141592653589793, -2.1073424255447014e-08) > Received: complex(3.141592653589793, -2.1073424338879928e-08) > Received value insufficiently close to expected value. > > > test_float > test test_float failed -- Traceback (most recent call last): > File "/root/tools/python3/Python-3.1.2/Lib/test/test_float.py", line 479, > in > self.assertEqual(s, repr(float(s))) > AssertionError: '8.72293771110361e+25' != '8.722937711103609e+25' > > > test_math > test test_math failed -- multiple errors occurred; run in verbose mode for > deta > > => > > runtests.sh -v test_math > > le01:~/tools/python3/Python-3.1.2# ./runtests.sh -v test_math > test_math BAD > 1 BAD > 0 GOOD > 0 SKIPPED > 1 total > le01:~/tools/python3/Python-3.1.2# > > To manage notifications about this bug go to: > https://bugs.launchpad.net/qemu/+bug/645662/+subscriptions -- Arno Wagner, Dr. sc. techn., Dipl. Inform., Email: a...@wagner.name GnuPG: ID: CB5D9718 FP: 12D6 C03B 1B30 33BB 13CF B774 E35C 5FA1 CB5D 9718 ---- A good decision is based on knowledge and not on numbers. -- Plato If it's in the news, don't worry about it. The very definition of "news" is "something that hardly ever happens." -- Bruce Schneier -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/645662 Title: QEMU x87 emulation of trig and other complex ops is only at 64-bit precision, not 80-bit Status in QEMU: Confirmed Bug description: When doing the regression tests for Python 3.1.2 with Qemu 0.12.5, (Linux version 2.6.26-2-686 (Debian 2.6.26-25lenny1)), gcc (Debian 4.3.2-1.1) 4.3.2, Python compiled from sources within qemu, 3 math tests fail, apparently because the floating point unit is buggy. Qmeu was compiled from original sources on Debian Lenny with kernel 2.6.34.6 from kernel.org, gcc (Debian 4.3.2-1.1) 4.3. Regression testing errors: test_cmath test test_cmath failed -- Traceback (most recent call last): File "/root/tools/python3/Python-3.1.2/Lib/test/test_cmath.py", line 364, in self.fail(error_message) AssertionError: acos0034: acos(complex(-1.0000000000000002, 0.0)) Expected: complex(3.141592653589793, -2.1073424255447014e-08) Received: complex(3.141592653589793, -2.1073424338879928e-08) Received value insufficiently close to expected value. test_float test test_float failed -- Traceback (most recent call last): File "/root/tools/python3/Python-3.1.2/Lib/test/test_float.py", line 479, in self.assertEqual(s, repr(float(s))) AssertionError: '8.72293771110361e+25' != '8.722937711103609e+25' test_math test test_math failed -- multiple errors occurred; run in verbose mode for deta => runtests.sh -v test_math le01:~/tools/python3/Python-3.1.2# ./runtests.sh -v test_math test_math BAD 1 BAD 0 GOOD 0 SKIPPED 1 total le01:~/tools/python3/Python-3.1.2# To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/645662/+subscriptions
