The testcase from PR40021:
http://gcc.gnu.org/bugzilla/attachment.cgi?id=17800&action=view
shows a current problem in optimizing away logical operations on logical
(boolean) types, like "x | 1" --> "1". This folding is done in some contexts,
and not in others. In particular the testcase
(with -m32 -O2 -ftree-vectorize -msse2 -mfpmath=sse -ffast-math )
leaves this until expand (it's generated quite early already, so there
are multiple possibilities to fold it):
D.1650_109 = D.1648_107 | 1;
if (D.1650_109 != 0)
goto <bb 6>;
else
goto <bb 5>;
Richi already fiddled a bit with this, so CCing him.
--
Summary: missed optimizations on logical types: (x | 1) --> 1
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: matz at gcc dot gnu dot org
GCC host triplet: x86_64-unknown-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40052
