[Bug middle-end/67639] New: ICE at -O1 and above on x86_64-linux-gnu in expand_gimple_basic_block, at cfgexpand.c:5697

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67639

            Bug ID: 67639
           Summary: ICE at -O1 and above on x86_64-linux-gnu in
                    expand_gimple_basic_block, at cfgexpand.c:5697
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu
  Target Milestone: ---

The following (invalid) code causes an ICE when compiled with the current gcc
trunk at -O1 and above on x86_64-linux-gnu in the 64-bit mode (but not in
32-bit mode). 

This is a regression from 5.2.x. 


$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk/configure --prefix=/usr/local/gcc-trunk
--enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
gcc version 6.0.0 20150919 (experimental) [trunk revision 227932] (GCC) 
$ 
$ gcc-trunk -m64 -O0 -c small.c
small.c: In function ‘foo’:
small.c:5:17: error: invalid register name for ‘x’
   register long x asm ("r2") = p;
                 ^
$ gcc-trunk -m32 -O1 -c small.c
small.c: In function ‘foo’:
small.c:5:17: error: invalid register name for ‘x’
   register long x asm ("r2") = p;
                 ^
$ gcc-5.2 -m64 -O1 -c small.c
small.c: In function ‘foo’:
small.c:5:17: error: invalid register name for ‘x’
   register long x asm ("r2") = p;
                 ^
$ 
$ gcc-trunk -m64 -O1 -c small.c
small.c: In function ‘foo’:
small.c:5:17: error: invalid register name for ‘x’
   register long x asm ("r2") = p;
                 ^
small.c:2:1: internal compiler error: tree check: expected ssa_name, have
var_decl in expand_gimple_basic_block, at cfgexpand.c:5697
 foo (int p)
 ^
0xd292cc tree_check_failed(tree_node const*, char const*, int, char const*,
...)
        ../../gcc-trunk/gcc/tree.c:9512
0x6f8e36 tree_check(tree_node*, char const*, int, char const*, tree_code)
        ../../gcc-trunk/gcc/tree.h:2858
0x6f8e36 expand_gimple_basic_block
        ../../gcc-trunk/gcc/cfgexpand.c:5697
0x6fdfc6 execute
        ../../gcc-trunk/gcc/cfgexpand.c:6286
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.
$ 


-----------------------------------------------


void
foo (int p)
{
  int t; 
  register long x asm ("r2") = p;
  __asm ("mov %0, %1;" : "=r" (t), "=r" (t), "=r" (t), "=r" (x) : "0" (x));
}