[Bug tree-optimization/69070] New: [6 Regression] ICE: tree check: expected real_cst, have ssa_name in gimple_expand_builtin_pow, at tree-ssa-math-opts.c:1541 with -fsignaling-nans and powl()

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69070

            Bug ID: 69070
           Summary: [6 Regression] ICE: tree check: expected real_cst,
                    have ssa_name in gimple_expand_builtin_pow, at
                    tree-ssa-math-opts.c:1541 with -fsignaling-nans and
                    powl()
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu

Created attachment 37176
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37176&action=edit
reduced testcase

Compiler output:
$ gcc -O -fsignaling-nans testcase.c 
testcase.c: In function 'foo':
testcase.c:2:1: internal compiler error: tree check: expected real_cst, have
ssa_name in gimple_expand_builtin_pow, at tree-ssa-math-opts.c:1541
 foo (double d)
 ^~~

0xe082cc tree_check_failed(tree_node const*, char const*, int, char const*,
...)
        /repo/gcc-trunk/gcc/tree.c:9603
0xcff81d tree_check(tree_node*, char const*, int, char const*, tree_code)
        /repo/gcc-trunk/gcc/tree.h:2998
0xcff81d gimple_expand_builtin_pow
        /repo/gcc-trunk/gcc/tree-ssa-math-opts.c:1541
0xd0024b execute
        /repo/gcc-trunk/gcc/tree-ssa-math-opts.c:1823
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.

$ gcc -v                                
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-231954-checking-yes-rtl-df-nographite/bin/../libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-checking=yes,rtl,df --without-cloog --without-ppl --without-isl
--disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-231954-checking-yes-rtl-df-nographite
Thread model: posix
gcc version 6.0.0 20151225 (experimental) (GCC)