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* [Bug ports/13742] New: Use of fsincos is incorrect for large input on m68k @ 2012-02-24 16:13 carlos at systemhalted dot org 2012-02-24 16:13 ` [Bug ports/13742] " carlos at systemhalted dot org ` (3 more replies) 0 siblings, 4 replies; 5+ messages in thread From: carlos at systemhalted dot org @ 2012-02-24 16:13 UTC (permalink / raw) To: glibc-bugs http://sourceware.org/bugzilla/show_bug.cgi?id=13742 Bug #: 13742 Summary: Use of fsincos is incorrect for large input on m68k Product: glibc Version: unspecified Status: NEW Severity: normal Priority: P2 Component: ports AssignedTo: unassigned@sourceware.org ReportedBy: carlos@systemhalted.org CC: carlos@systemhalted.org, roland@gnu.org, schwab@linux-m68k.org Classification: Unclassified Target: m68k-linux-gnu This bug: http://sourceware.org/bugzilla/show_bug.cgi?id=13658 Raises the question of the accuracy of hardware fsincos instructions for large inputs. It would appear that this bug, present on x86 and x86_64, would also effect m68k since it uses a fsincos instruction with limited accuracy at high input values. A quick grep shows: sysdeps/m68k/m680x0/fpu/s_csin.c: __asm ("fsincos%.x %2,%1:%0" : "=f" (sin_rx), "=f" (cos_rx) sysdeps/m68k/m680x0/fpu/bits/mathinline.h: __asm ("fsincos%.x %2,%1:%0" \ sysdeps/m68k/m680x0/fpu/k_sin.c: __asm__ __volatile__ ("fsincosx %2,%0:%1" : "=f" (cos_x), "=f" (sin_x) sysdeps/m68k/m680x0/fpu/k_sin.c: __asm__ __volatile__ ("fsincosx %2,%0:%1" : "=f" (cos_y), "=f" (sin_y) sysdeps/m68k/m680x0/fpu/s_ccosh.c: __asm ("fsincos%.x %2,%1:%0" : "=f" (sin_ix), "=f" (cos_ix) sysdeps/m68k/m680x0/fpu/s_csinh.c: __asm ("fsincos%.x %2,%1:%0" : "=f" (sin_ix), "=f" (cos_ix) sysdeps/m68k/m680x0/fpu/k_cos.c: __asm__ __volatile__ ("fsincosx %2,%0:%1" : "=f" (cos_x), "=f" (sin_x) sysdeps/m68k/m680x0/fpu/k_cos.c: __asm__ __volatile__ ("fsincosx %2,%0:%1" : "=f" (cos_y), "=f" (sin_y) sysdeps/m68k/m680x0/fpu/s_cexp.c: __asm ("fsincos%.x %2,%1:%0" : "=f" (sin_ix), "=f" (cos_ix) A quick inspection does not show any input argument reduction. The M68000PM/AD REV.1 states loss of accuracy if the input is > 10^20. Therefore it seems to me that the m68k port also suffers the same problems as x86 and x86_64. -- Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug ports/13742] Use of fsincos is incorrect for large input on m68k 2012-02-24 16:13 [Bug ports/13742] New: Use of fsincos is incorrect for large input on m68k carlos at systemhalted dot org @ 2012-02-24 16:13 ` carlos at systemhalted dot org 2012-04-05 9:28 ` aj at suse dot de ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: carlos at systemhalted dot org @ 2012-02-24 16:13 UTC (permalink / raw) To: glibc-bugs http://sourceware.org/bugzilla/show_bug.cgi?id=13742 Carlos O'Donell <carlos at systemhalted dot org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |UNCONFIRMED Ever Confirmed|1 |0 -- Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug ports/13742] Use of fsincos is incorrect for large input on m68k 2012-02-24 16:13 [Bug ports/13742] New: Use of fsincos is incorrect for large input on m68k carlos at systemhalted dot org 2012-02-24 16:13 ` [Bug ports/13742] " carlos at systemhalted dot org @ 2012-04-05 9:28 ` aj at suse dot de 2014-02-11 0:31 ` [Bug math/13742] [m68k] " jsm28 at gcc dot gnu.org 2014-06-26 15:15 ` fweimer at redhat dot com 3 siblings, 0 replies; 5+ messages in thread From: aj at suse dot de @ 2012-04-05 9:28 UTC (permalink / raw) To: glibc-bugs http://sourceware.org/bugzilla/show_bug.cgi?id=13742 Andreas Jaeger <aj at suse dot de> changed: What |Removed |Added ---------------------------------------------------------------------------- AssignedTo|unassigned at sourceware |schwab@linux-m68k.org |dot org | -- Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug math/13742] [m68k] Use of fsincos is incorrect for large input on m68k 2012-02-24 16:13 [Bug ports/13742] New: Use of fsincos is incorrect for large input on m68k carlos at systemhalted dot org 2012-02-24 16:13 ` [Bug ports/13742] " carlos at systemhalted dot org 2012-04-05 9:28 ` aj at suse dot de @ 2014-02-11 0:31 ` jsm28 at gcc dot gnu.org 2014-06-26 15:15 ` fweimer at redhat dot com 3 siblings, 0 replies; 5+ messages in thread From: jsm28 at gcc dot gnu.org @ 2014-02-11 0:31 UTC (permalink / raw) To: glibc-bugs https://sourceware.org/bugzilla/show_bug.cgi?id=13742 Joseph Myers <jsm28 at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Component|ports |math Host| |m68k-*-* Summary|Use of fsincos is incorrect |[m68k] Use of fsincos is |for large input on m68k |incorrect for large input | |on m68k -- You are receiving this mail because: You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug math/13742] [m68k] Use of fsincos is incorrect for large input on m68k 2012-02-24 16:13 [Bug ports/13742] New: Use of fsincos is incorrect for large input on m68k carlos at systemhalted dot org ` (2 preceding siblings ...) 2014-02-11 0:31 ` [Bug math/13742] [m68k] " jsm28 at gcc dot gnu.org @ 2014-06-26 15:15 ` fweimer at redhat dot com 3 siblings, 0 replies; 5+ messages in thread From: fweimer at redhat dot com @ 2014-06-26 15:15 UTC (permalink / raw) To: glibc-bugs https://sourceware.org/bugzilla/show_bug.cgi?id=13742 Florian Weimer <fweimer at redhat dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Flags| |security- -- You are receiving this mail because: You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2014-06-26 15:15 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2012-02-24 16:13 [Bug ports/13742] New: Use of fsincos is incorrect for large input on m68k carlos at systemhalted dot org 2012-02-24 16:13 ` [Bug ports/13742] " carlos at systemhalted dot org 2012-04-05 9:28 ` aj at suse dot de 2014-02-11 0:31 ` [Bug math/13742] [m68k] " jsm28 at gcc dot gnu.org 2014-06-26 15:15 ` fweimer at redhat dot com
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