[Bug c/11395] New: problem with asm inserts used as immediate arguments

[hoffman at cray dot com]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11395

           Summary: problem with asm inserts used as immediate arguments
           Product: gcc
           Version: 3.2.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: hoffman at cray dot com
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: x86_64-suse-linux
  GCC host triplet: x86_64-suse-linux
GCC target triplet: x86_64-suse-linux

the following fragment will segv gcc

t64.c: In function `main':                                                      
t64.c:16: internal error: Segmentation fault   

#define __byte_swap_word(x) \                                                   
({ register unsigned short __X = (x); \                                         
   __asm ("xchgb %h1, %b1" \                                                    
: "=q" (__X) \                                                                  
: "0" (__X)); \                                                                 
   __X; })                                                                      
                                                                                
void foo(short x)                                                               
{                                                                               
}                                                                               
                                                                                
main()                                                                          
{                                                                               
  foo(__byte_swap_word(5));                                                     
}                                                                               
 

the problem goes away if:
  the register declaration before __X is removed
  the result of the macro is stored into a temporary before used as an argument
    to foo