Since I gave bad advice last time, how about one more advice? :-) Create a DenseMap mapping from target registers to dwarf numbers at X86RegisterInfo ctor (or on demand the first time getDwarfRegNum is called). So subsequent queries should be nice and fast.
Frankly I don't think the issue is worth spending this much time on. Whatever works and maintainable is good. Evan On Nov 9, 2007, at 8:13 AM, Dale Johannesen wrote: > > On Nov 8, 2007, at 10:05 PM, Chris Lattner wrote: > >>> URL: http://llvm.org/viewvc/llvm-project?rev=43918&view=rev >>> Log: >>> Rewrite Dwarf number handling per review comments. >> >> Hi Dale, >> >> I'm pretty uncomfortable with this, because it means that we're tying >> down the register order. > > I tend to agree, but both comments I got on this patch suggested the > table approach. > > Actually the more I look at other people's suggestions the more I > like my original patch (43844). > Compared to your suggestion below, that has 2 switches instead of 3 > and the switches > are smaller, and it's also proof against reordering of registers. > What do you think of that one? > >> How about something like: >> >> if (Darwin32) { >> switch (RegNo) { >> case X86::AL: case X86::AH: case X86::AX: return 0; >> case X86::EDI: ... >> } else if (darwin64) { >> switch (RegNo) { >> ... >> } else { >> } >> >> That way we don't break EH/debug info if registers are reordered or >> added in the future. >> >> -Chris >> >> _______________________________________________ >> llvm-commits mailing list >> llvm-commits@cs.uiuc.edu >> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits > > _______________________________________________ > llvm-commits mailing list > llvm-commits@cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
