http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49543
--- Comment #5 from Alexander Carmeli <acarmeli at mathworks dot com> 2011-06-27 20:15:37 UTC --- That's a good point. I removed the const and g++ fails as well. Therefore, the bug is in the C++ compiler too. Consts can be promoted as well. Why promote the non-const expression and not promote the const expression? The const expression is constant-folded as a 32-bit subtraction. Therefore, so should the non-const expression. Otherwise, numerical results depend on the arguments being const or not, and that's problematic. My claims still hold: - Expression folding should not change numerical results compared to unfolded expressions. - It is not okay to promote to 64 bit. The value is undefined. The size is. - If -pedantic compiles, it should generate he same results as without -pedantic.
