[Bug rtl-optimization/34773] [4.3 regression] miscompilation of vfprintf_r

[hp at gcc dot gnu dot org]

------- Comment #3 from hp at gcc dot gnu dot org  2008-01-26 22:56 -------
I just checked with the gcc-4.2-20080123.tar.bz2 and the bug doesn't manifest
there with the vf.c testcase, so I'm marking this as a regression.
I also no longer think it's fwprop's error (at least not alone); the
into_cfglayout pass (really: try_optimize_cfg(CLEANUP_CFGLAYOUT)) suboptimally
changes an unconditional jump into a fallthrough to a basic block that already
has a fallthrough.  Perhaps that's meant to be cleaned up, but it isn't. 
(Neither the generic nor the cfglayout-specific verify_flow_info code tests
that a basic block has at most one predecessor edge.)


-- 

hp at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|fwprop1 bug causing         |[4.3 regression]
                   |miscompilation of vfprintf_r|miscompilation of vfprintf_r


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34773