On Nov 12, 2007, "Steven Bosscher" <[EMAIL PROTECTED]> wrote:
> DEBUG_INSN in RTL (with one noteworthy difference, namely that having > note-like GIPMLE statements is a totally new concept Not quite. There were codeless gimple constructs before (think labels, for one). Or empty asm statements. But then, I'm not sure what you mean by note-like; maybe it's something else. As I explained before, debug insns and debug stmts are more like code than like notes, because notes generally don't need adjusting as code is modified elsewhere, whereas code does. And debug insns and stmts definitely need adjusting like regular insns. > while DEBUG_INSN is just a wannabe-real-insn INSN_NOTE). Except for this tiny detail that INSN_NOTEs are never adjusted as code is modified, because in general they don't even contain RTL. VAR_LOCATION is a recent exception, and it used to be introduced so late precisely because there's no infrastructure to keep notes up-to-date as code transformations are performed. So, yes, debug stmts and insns are notes in the sense that they don't output code. Like USE insns, labels, empty asm insns and other UNSPECs. But wait, those are insns, not notes. And they do generate code, just not in the .text section, but rather in .debug sections. So, what's this prejudice against debug insns? Why do you regard them as notes rather than insns? -- Alexandre Oliva http://www.lsd.ic.unicamp.br/~oliva/ FSF Latin America Board Member http://www.fsfla.org/ Red Hat Compiler Engineer [EMAIL PROTECTED], gcc.gnu.org} Free Software Evangelist [EMAIL PROTECTED], gnu.org}
