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[Bug inline-asm/49611] Inline asm should support input/output of flags
- From: "scovich at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Mon, 4 Jul 2011 20:32:07 +0000
- Subject: [Bug inline-asm/49611] Inline asm should support input/output of flags
- Auto-submitted: auto-generated
- References: <bug-49611-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49611
--- Comment #2 from Ryan Johnson <scovich at gmail dot com> 2011-07-04 20:32:01 UTC ---
(In reply to comment #1)
> Making this work reliably is probably more work than making GCC use the flags
> from more cases from regular C code.
Does that mean each such case would need to be identified individually and then
hard-wired into i386.md? The existence of modes like CCGC, CCGOC, CCNO, etc. in
i386-modes.def made me hope that some high-level mechanism existed for
reasoning about the semantics of condition codes. Or does that mechanism exist,
and is just difficult to expose to inline asm for some reason?