[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

[rguenth at gcc dot gnu.org]

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

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
At least latent on the GCC 7 branch and earlier.

  /* We start expression rewriting from the top statements.
     So, in this loop we create a full list of statements
     we will work with.  */
  stmts[stmt_num - 1] = stmt;
  for (i = stmt_num - 2; i >= 0; i--)
    stmts[i] = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmts[i+1]));

assumes there are no unfolded CST +* CST ops in the IL.

OTOH we shouldn't rewrite any exprs with -frounding-math anyway?

That is, -fassociative-math and -frounding-math are (again) seemingly in
conflict?