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[Bug rtl-optimization/51821] [4.5/4.6/4.7 Regression] 64bit > 32bit conversion produces incorrect results with optimizations
- From: "ebotcazou at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Wed, 11 Jan 2012 22:03:16 +0000
- Subject: [Bug rtl-optimization/51821] [4.5/4.6/4.7 Regression] 64bit > 32bit conversion produces incorrect results with optimizations
- Auto-submitted: auto-generated
- References: <bug-51821-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51821
Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
AssignedTo|unassigned at gcc dot |ebotcazou at gcc dot
|gnu.org |gnu.org
--- Comment #7 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2012-01-11 22:03:16 UTC ---
> RTL infrastructure bug, adding some CCs that might find it interesting.
Ugh. The problem is that the df_simulate_* routines don't correctly handle
hard registers. Oddly enough, there is an isolated use of hard_regno_nregs in
the df_simulate_one_insn_forwards routine, but with no comment whatsoever.
We need to do something, but the impact of the change isn't very clear.