------- Comment #4 from burnus at gcc dot gnu dot org 2007-09-11 15:34 ------- > > -fstrict-overflow > > Allow the compiler to assume strict signed overflow rules, depending on the > > language being compiled. > Well, I think the "depending on the language being compiled" is important. I > think the testcase is valid Fortran, and shouldn't fail whatever the > optimization level you use.
I'm not sure; for -O2 maybe not but for -O3? If one takes overflows (integer, floating point variables), +/-Inf, NaN (only fp) fully into account, many optimizations are no longer possible. Example: "if (i + 10 > 20)"; should this be optimized to "if(i > 10)" or not? And if yes, starting from which optimization level? See also (for FP math): http://gcc.gnu.org/wiki/GeertBosch -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33391
