4 ms·

More and interesting conversation happens here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61904 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61904

by e40 12y ago

frik 12y ago
> The bad compiler versions are 4.5.0 (when debug_insn came in) to 4.8.3 and 4.9.0 and 4.9.1.
wfunction 12y ago
"Here's a small (auto-)reduced testcase for this specific issue" Do you happen to know how that is done? How is a test case "auto"-reduced? I've never done that before.
- kzrdude 12y ago
  For example http://embed.cs.utah.edu/creduce/ http://embed.cs.utah.edu/creduce/ ; the slides from a presentation in 2012 are interesting: http://embed.cs.utah.edu/creduce/pldi12_talk.pdf http://embed.cs.utah.edu/creduce/pldi12_talk.pdf
  - wfunction 12y ago
    Thank you!
  - jpgvm 12y ago
    This is awesome, thanks mate!
    - gwern 12y ago
      If you find this topic interesting, look up everything written by http://blog.regehr.org/ http://blog.regehr.org/
- a3_nm 12y ago
  https://gcc.gnu.org/wiki/A_guide_to_testcase_reduction https://gcc.gnu.org/wiki/A_guide_to_testcase_reduction
  - wfunction 12y ago
    Thank you!
- dochtman 12y ago
  The LLVM project recommends delta: http://delta.tigris.org/ http://delta.tigris.org/
- CyberShadow 12y ago
  For D we use DustMite (disclaimer: I'm the author). It also works to some extent with C/C++ (thanks to the languages' syntax being similar enough). https://github.com/CyberShadow/DustMite/wiki https://github.com/CyberShadow/DustMite/wiki
rwmj 12y ago
I think it's a case of "bugs happen". They fixed this one pretty quickly.
HCIdivision17 12y ago
The tone difference is certainly stark! The bug report feels like a process is in play, while the mail has a tone of a rant in a closed room. I often take it for granted the compiler is always right (and it darn well just about is), but bugs like this look exactly like mis-cast magic to me. Learning how the compiler makes decisions seems like a rabbit hole, but may be fascinating enough to be worth it. (And think about being a maintainer of such a complex beast!)

More and interesting conversation happens here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61904 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61904

by e40 12y ago

More and interesting conversation happens here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61904 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61904

frik 12y ago

> The bad compiler versions are 4.5.0 (when debug_insn came in) to 4.8.3 and 4.9.0 and 4.9.1.

wfunction 12y ago

"Here's a small (auto-)reduced testcase for this specific issue" Do you happen to know how that is done? How is a test case "auto"-reduced? I've never done that before.

kzrdude 12y ago
For example http://embed.cs.utah.edu/creduce/ http://embed.cs.utah.edu/creduce/ ; the slides from a presentation in 2012 are interesting: http://embed.cs.utah.edu/creduce/pldi12_talk.pdf http://embed.cs.utah.edu/creduce/pldi12_talk.pdf
- wfunction 12y ago
  Thank you!
- jpgvm 12y ago
  This is awesome, thanks mate!
  - gwern 12y ago
    If you find this topic interesting, look up everything written by http://blog.regehr.org/ http://blog.regehr.org/
a3_nm 12y ago
https://gcc.gnu.org/wiki/A_guide_to_testcase_reduction https://gcc.gnu.org/wiki/A_guide_to_testcase_reduction
- wfunction 12y ago
  Thank you!
dochtman 12y ago
The LLVM project recommends delta: http://delta.tigris.org/ http://delta.tigris.org/
CyberShadow 12y ago
For D we use DustMite (disclaimer: I'm the author). It also works to some extent with C/C++ (thanks to the languages' syntax being similar enough). https://github.com/CyberShadow/DustMite/wiki https://github.com/CyberShadow/DustMite/wiki

rwmj 12y ago

I think it's a case of "bugs happen". They fixed this one pretty quickly.

HCIdivision17 12y ago

The tone difference is certainly stark! The bug report feels like a process is in play, while the mail has a tone of a rant in a closed room. I often take it for granted the compiler is always right (and it darn well just about is), but bugs like this look exactly like mis-cast magic to me. Learning how the compiler makes decisions seems like a rabbit hole, but may be fascinating enough to be worth it. (And think about being a maintainer of such a complex beast!)