[Bug tree-optimization/71109] New: gcc ICE at -O3 on valid code on x86_64-linux-gnu in "maybe_record_trace_start"

[helloqirun at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71109

            Bug ID: 71109
           Summary: gcc ICE at -O3 on valid code on x86_64-linux-gnu in
                    "maybe_record_trace_start"
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: helloqirun at gmail dot com
  Target Milestone: ---

The following valid code causes an ICE when compiled with the current gcc trunk
at only -O3 on x86_64-linux-gnu in 64-bit mode. 32-bit mode works fine.

It appears to be a 7 regression.

$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/home/absozero/trunk/root-gcc/libexec/gcc/x86_64-pc-linux-gnu/7.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc/configure --prefix=/home/absozero/trunk/root-gcc
--enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
gcc version 7.0.0 20160513 (experimental) [trunk revision 236209] (GCC)


$ gcc-trunk -O3 abc.c -c
abc.c: In function ‘fn2’:
abc.c:26:1: internal compiler error: in maybe_record_trace_start, at
dwarf2cfi.c:2284
 }
 ^
0x827738 maybe_record_trace_start
        ../../gcc/gcc/dwarf2cfi.c:2284
0x829e30 scan_trace
        ../../gcc/gcc/dwarf2cfi.c:2462
0x82a66a create_cfi_notes
        ../../gcc/gcc/dwarf2cfi.c:2616
0x82a66a execute_dwarf2_frame
        ../../gcc/gcc/dwarf2cfi.c:2974
0x82a66a execute
        ../../gcc/gcc/dwarf2cfi.c:3454
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.



$ cat abc.c
struct S0 {
  int f0;
  int f1;
  char f2;
  int f3;
  char f4;
  int f5;
  int f6;
  int f7;
  char f8;
} a, c;
struct S1 {
  char f0;
} e;
int *b;
int d;
void fn1();
void fn2() {
  for (; d;) {
    fn1(fn2, a);
    struct S1 f[3];
    int k;
    for (;; k++)
      f[k] = e;
  }
}
void fn1(int p1, struct S0 p2, struct S1 p3) {
  p3.f0 = 2;
  for (; p3.f0; p3.f0--) {
    struct S0 *g = &a, *h = &c;
    *h = *g = p2;
    *b |= 6;
    if (p2.f0)
      break;
  }
}