[Bug middle-end/78977] [7 Regression] g++7 snprintf() of double produces wrong code with -O3

[h2+bugs at fsfe dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78977

--- Comment #9 from Hannes Hauswedell <h2+bugs at fsfe dot org> ---
Created attachment 40453
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40453&action=edit
intermediate for O3