[Bug ipa/71374] New: ICE on valid code at -O1 and above on x86_64-linux-gnu: in extract_constrain_insn, at recog.c:2190

["su at cs dot ucdavis.edu" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71374

            Bug ID: 71374
           Summary: ICE on valid code at -O1 and above on
                    x86_64-linux-gnu: in extract_constrain_insn, at
                    recog.c:2190
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ipa
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu
  Target Milestone: ---

The following code causes an ICE when compiled with the current GCC trunk (and
5.x and 6.x) at -O1 and above on x86_64-linux-gnu in both 32-bit and 64-bit
modes.  

This is a regression from 4.9.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/7.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/usr/local/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 7.0.0 20160601 (experimental) [trunk revision 236978] (GCC)
$
$ gcc-trunk -O0 -c small.c
$ gcc-4.9 -O1 -c small.c
$
$ gcc-trunk -O1 -c small.c
small.c: In function âfn1â:
small.c:5:1: error: unrecognizable insn:
 }
 ^
(insn 10 4 15 2 (parallel [
            (set (reg:SI 2 cx [89])
                (asm_operands:SI ("") ("=&c") 0 [
                        (reg/v/f:DI 4 si [orig:88 p2 ] [88])
                        (reg/v/f:DI 4 si [orig:88 p2 ] [88])
                    ]
                     [  
                        (asm_input:DI ("0q") small.c:4)
                        (asm_input:DI ("2") small.c:4)
                    ]
                     [] small.c:4))
            (set (reg:SI 5 di [90])
                (asm_operands:SI ("") ("=&D") 1 [
                        (reg/v/f:DI 4 si [orig:88 p2 ] [88])
                        (reg/v/f:DI 4 si [orig:88 p2 ] [88])
                    ]
                     [  
                        (asm_input:DI ("0q") small.c:4)
                        (asm_input:DI ("2") small.c:4)
                    ]
                     [] small.c:4))
            (set (reg:SI 4 si [orig:88 p2 ] [88])
                (asm_operands:SI ("") ("=&S") 2 [
                        (reg/v/f:DI 4 si [orig:88 p2 ] [88])
                        (reg/v/f:DI 4 si [orig:88 p2 ] [88])
                    ]
                     [  
                        (asm_input:DI ("0q") small.c:4)
                        (asm_input:DI ("2") small.c:4)
                    ]
                     [] small.c:4))
            (clobber (reg:CCFP 18 fpsr))
            (clobber (reg:CC 17 flags))
        ]) small.c:4 -1
     (nil))
small.c:5:1: internal compiler error: in extract_constrain_insn, at
recog.c:2190
0xb56908 _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
        ../../gcc-source-trunk/gcc/rtl-error.c:108
0xb56939 _fatal_insn_not_found(rtx_def const*, char const*, int, char const*)
        ../../gcc-source-trunk/gcc/rtl-error.c:116
0xb24c3d extract_constrain_insn(rtx_insn*)
        ../../gcc-source-trunk/gcc/recog.c:2190
0xa4756f check_rtl
        ../../gcc-source-trunk/gcc/lra.c:2022
0xa4b379 lra(_IO_FILE*)
        ../../gcc-source-trunk/gcc/lra.c:2432
0xa01be9 do_reload
        ../../gcc-source-trunk/gcc/ira.c:5384
0xa01be9 execute
        ../../gcc-source-trunk/gcc/ira.c:5568
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.
$


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


int a, b, c;
extern inline void fn1 (void *p1, void *p2)
{ 
  __asm__ ("": "=&c" (a), "=&D" (b), "=&S" (c):"0q" (p2), "2" (p2));
}