On Mon, May 14, 2007 at 10:35:57AM +0100, Andrew Haley wrote: : Claus Fischer writes: : > On Mon, May 14, 2007 at 10:18:26AM +0100, Andrew Haley wrote: : > : Claus Fischer writes: : > : > : > : > I think I found a code generation bug in GCC 4.0.1. : > : > : > : > I'm sending this mail to make sure this bug is known and : > : > is or will be removed in newer versions. : > : > On a quick glance I couldn't find it in the bug database, : > : > so it may not be known. : > : : > : Redirected to gcc-help. : > : : > : Please send a full test case that can be run, with full information : > : about the expected effect. : > : > : > The full test case is way too big to run and contains data : > which I don't have authority to disclose publicly. : : I'm not asking for your full code. If you believe that the bug is in : the code generated for the source you posted, presumably you can : create a test wrapper. I can, but it's likely to take me more than five times as long as someone who knows assembler to take a (quick) glance. If that quick glance doesn't get us further, I'm very willing to do my homework/test case, even though just switching to gcc 4.1 would probably solve MY problem completely. It's just out of desire to help gcc people keep gcc bug-free that I have tried to "isolate" this bug. I have already spent a lot of time tracking this down, and I feel I have reached a point where the imbalance of time I'd have to spend to create a complete test case, and of the time required to look at the assembly, is grossly in favor of learning assembly myself :-) [ Unfortunately, creating the MINGW cross compilation environment itself is a task that would probably keep most gcc developers from examining the case, even if I posted the instructions. ] : Experience over meny years has shown us that this is the bet way to : find and fix bugs in gcc. It's much more productive than staring at : thousands of lines of assembly language. I know and understand. I typically try to do that. But that's easier for a recent GCC as shipped with Linux, than for a cross-compilation environment that involves Mingw and an older GCC. : The problem is that gcc reorders and reorganizes code to such an : extent that it can be exceedingly hard to find the equivalent code. I understand that. Claus -- Claus Fischer <claus.fischer@xxxxxxxxxxxxxxxx> http://www.clausfischer.com/
