Hi Nick, Thank you, by omitting -ggdb I could now produce untruncated source lines and was able to locate easily the pieces of interest for me.
If it always worked, then it could be all right: one build for the listings if they are needed, and another build for the debugger. But as you experienced, too, it may not always work: there is something somewhere deeply down which sometimes finds its way up to the surface and sometimes doesn't. Next time it does, I'll file a bug report in bugzilla. br PK On Fri, 2024-09-27 at 15:58 +0100, Nick Clifton wrote: > Hi Peter, > > I wanted to know how exactly gcc translates such expressions like > > n * 0x1001. People are talking about multiplication being not > > slower > > than any other arithmetic operation on modern processors, but in > > fact I > > got the code (n << 12) + n, no matter which form I used in the C > > source. OK, it was with -O0, but it would be quite illogical to > > translate multiplication to shift on -O0, and to multiplication on > > -O3. > > > > Not frequently, but similar question occur from time to time. > > Have you tried using gcc's -fverbose-asm option (in conjunction with > -S) ? > This should give you the same information, but without having to deal > with > the assembler's listing problems. > > > > The default assembly listing page width is too narrow, > > Darn - that scuppers my current patch of limiting the listing's > maximum > width to the built in default of 100 columns... > > > I don't like > > reading folded source lines, truncated lines are even worse (or > > better?). Even 132 characters are not enough, but rhs-width > > wouldn't > > work with whatever sensible width. > > Another potential workaround is to skip the assembler's listing > output > and instead disassemble the object file with source code annotation > enabled, > ie "objdump -d -S". > > > > I am attaching the asm source. I applied the same command line, > > except > > -c replaced by -S. > > And weirdly I now cannot reproduce the problem. Either with the .s > file > you supplied or the version I created yesterday. Very strange. > > I think that the short answer is that this bug is not going to be > fixed > quickly, so if you can make use of a workaround please do so. If > not, > please file a bug report with a test case and we will see if someone > out there decides to investigate. (If no-one does then it will be up > to > me, but I am rather swamped at the moment). > > Cheers > Nick > > >
