"Deng Shi" <Deng.Shi@xxxxxxxxxxxx> writes: > I found our application tool gave the inconsistent floating point result when using different optimization level -O0 or -O1. http://gcc.gnu.org/PR323 > Even if I used -O1 plus all the disabling options which includes in > -O1, like -O1 -fno-merge-all-constants -fno-zero-initialized-in-bss > -fno-function-cse -fno-keep-static-consts -fno-omit-frame-pointer > -fno-merge-constants -fno-loop-optimize -fno-cprop-registers > -fno-if-conversion -fno-if-conversion2 -fno-delayed-branch > -fno-guess-branch-probability -fno-defer-pop -fno-crossjumping > -fno-thread-jumps " which command line setting should be equal to > -O0, but I still didn't get the consistent result. > I wonder whether there is any additional optimization enabled by -O1 > for C++ language which is not documented in GCC manual? -O1 turns on optimization in general, affecting code generation in a -number of ways. -O1 is more than the sum of the -f options. Ian
