[Bug tree-optimization/43544] New: TARGET_VECTORIZE_BUILTIN_VECTORIZED_FUNCTION can misoptimize when MD builtins overlap with standard builtins

[meissner at gcc dot gnu dot org]

I was looking at the rs6000_builtin_vectorized_function and noticed that it
takes an integer that gives the builtin function index.  Unfortunately on the
powerpc and cell architectures, the builtin function id overlaps with the
system builtins, and you need to look at the builtin class before using the
builtin index.

This can be fixed in two ways, vectorizable_function in tree-vect-stmts.c can
add a check for DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL or the two
ports that use the hook (i386, rs6000) can be modified to take a tree instead
of the integer.  I tend to think the later is preferable, because it would
allow a MD scalar builtin to be vectorized.


-- 
           Summary: TARGET_VECTORIZE_BUILTIN_VECTORIZED_FUNCTION can
                    misoptimize when MD builtins overlap with standard
                    builtins
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: meissner at gcc dot gnu dot org
        ReportedBy: meissner at gcc dot gnu dot org
 GCC build triplet: powerpc64-unknown-linux-gnu
  GCC host triplet: powerpc64-unknown-linux-gnu
GCC target triplet: powerpc64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43544