https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88240
Bug 88240 depends on bug 86554, which changed state.
Bug 86554 Summary: [7 Regression] Incorrect code generation with
signed/unsigned comparison
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86554
What|Removed
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88240
Richard Biener changed:
What|Removed |Added
Keywords||wrong-code
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88240
--- Comment #11 from Thomas De Schampheleire ---
Any feedback? With the reduced testcase qemu is out of the picture.
Do you agree that this is a bug in gcc?
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88240
--- Comment #10 from Thomas De Schampheleire ---
I was able to further investigate and reduce the problem.
Qemu is now out of the picture, I can reproduce the issue directly on a real
CPU. All I need to do is enable the 'underflow' exception bit
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88240
--- Comment #9 from Florian Weimer ---
(In reply to Thomas De Schampheleire from comment #6)
> (In reply to Florian Weimer from comment #5)
> > This is QEMU with TCG, right? It could be an i387 emulation bug.
>
> I don't think so. Isn't it so
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88240
--- Comment #8 from Thomas De Schampheleire
---
To clarify the situation with underflow / denormal exception I will debug the
issue again and inspect the corresponding registers.
I'm not familiar with 'NaNs': is it a specific value that I can
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88240
--- Comment #7 from joseph at codesourcery dot com ---
As discussed, the load instructions should never raise underflow
exceptions, and having traps enabled for the nonstandard denormal operand
exception is clearly outside the scope of what
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88240
--- Comment #6 from Thomas De Schampheleire
---
(In reply to Florian Weimer from comment #5)
> (In reply to Thomas De Schampheleire from comment #4)
> > When analyzing this problem with gdb, we looked at the floating-point status
> > register
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88240
Florian Weimer changed:
What|Removed |Added
CC||fw at gcc dot gnu.org
--- Comment #5
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88240
--- Comment #4 from Thomas De Schampheleire
---
(In reply to Uroš Bizjak from comment #2)
> (In reply to Thomas De Schampheleire from comment #0)
> > gcc 7.3.0 optimizes below code in a way that may cause a floating-point
> > underflow (SIGFPE
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88240
Richard Biener changed:
What|Removed |Added
CC||rguenth at gcc dot gnu.org
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