[Bug tree-optimization/84841] [7/8 Regression] ICE: tree check: expected ssa_name, have real_cst in rewrite_expr_tree_parallel, at tree-ssa-reassoc.c:4624

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84841

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
On the other side, the assumption that +/* of two REAL_CSTs can be always
folded isn't false just for -frounding-math, but also e.g. with IBM long double
(aka composite mode) and no -funsafe-math-optimizations.  So e.g.
long double
foo (long double x, long double y)
{
  long double a = 10e50;
  long double b = 10e-50;
  a = a + b;
  a = a + x;
  a = a + y;
  return a;
}
with -mlong-double-128 -O2 -fassociative-math -fno-trapping-math
-fno-signed-zeros --param tree-reassoc-width=2
also has 2 REAL_CSTs in there that can't be folded together.