[Bug inline-asm/36639] New: pointer referenced in asm statement not regarded as VUSE

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

This is originally derived from code from Linux, in which the physical address
of a structure is passed to an asm statement as an integral type, causing the
initializer of the structure to be optimized away.

int main() { int i = 0x12345678; long j = (long)&i; asm ("# %0" : : "r" (j)); }

int main() { int i = 0x12345678; void *j = &i; asm ("#" : : "p" (j)); }

At the very least in the second case above, the compiler should mark the asm
statement as a VUSE of i.  Arguably, it should do so in the former case as
well, like it does for pointers passed to function calls as integral types.


-- 
           Summary: pointer referenced in asm statement not regarded as VUSE
           Product: gcc
           Version: 4.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: inline-asm
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: aoliva at gcc dot gnu dot org
 GCC build triplet: *-*-*
  GCC host triplet: *-*-*
GCC target triplet: *-*-*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36639