[Bug target/44987] New: *mmintrin.h files incompatible with partial __attribute__((target("sse...")))

["andi-gcc at firstfloor dot org" <gcc-bugzilla at gcc dot gnu dot org>]

The *mmintr.h files have checks like

#ifndef __SSE4_2__
# error "SSE4.2 instruction set not enabled"
#else

Problem with this is that it assumes that the whole file is compiled with 
-msse4.2 or similar option.

But with __attribute__((target(...))) it's possible and appropiate to 
let only part of the code use e.g. -msse4.2 and compile the rest
of the file with different options.

The problem is just that *mmintrin.h cannot be used then because 
__SSE4_2__ or similar is not set by the target attribute.

One workaround I found was to specify all the defines manually before
including the intrin.h header. But that's rather ugly because it needs
7 different defines or so.

I think it would be better to drop these #ifdefs from the headers
and check the code generation settings for the current function in
the intrinsics instead.


-- 
           Summary: *mmintrin.h files incompatible with partial
                    __attribute__((target("sse...")))
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: andi-gcc at firstfloor dot org
  GCC host triplet: x86_64-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44987