[Bug tree-optimization/105276] [12 Regression] executed once loop not optimized anymore

[amacleod at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105276

--- Comment #3 from Andrew Macleod <amacleod at redhat dot com> ---
Created attachment 52848
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52848&action=edit
proposed patch

When I removed the recursion from range_of_stmt, I neglected to incorporate the
existing known global range for an ssa-name into the calculated value.

Range_of_stmt does this, but the prefill calculation missed it.  This patch
fixes that oversight.