On Monday, December 07, 2015 at 06:47:36 PM, Wolfgang Denk wrote: > Dear Marek, > > In message <[email protected]> you wrote: > > Second is the coding which causes gcc 4.9.x and newer scream gruesome > > death and murder. The expression !x == 0 && !x == 1 is ambiguous and > > should instead be rewritten into (x != 0) && (x != 1) to be correct. > > But (!x == 0) && (!x == 1) ist not the same as (x != 0) && (x != 1); > assume x=2: > > (!2 == 0) && (!2 == 1) => (0 == 0) && (0 == 1) => 1 && 0 => 0 > > (2 != 0) && (2 != 1) => 1 && 1 => 1 > > ???
This really depends on where you put the parenthesis and GCC complains about such ambiguous expressions. That's what the paragraph is about. I never said that ((!x) == 0) && ((!x) == 1) <=> (x != 0) && (x != 1) or equally ((!x) == 0) && ((!x) == 1) <=> !(x == 0) && !(x == 1) Best regards, Marek Vasut _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
