Hi,
x86-64 psABI says _Bool has 1 byte and aligned at 1 byte. It also says: --- When a value of type _Bool is passed in a register or on the stack, the upper 63 bits of the eightbyte shall be zero. --- However, gcc treats _Bool as char: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42324 Given that gcc never zeros the upper 63 bits in register nor on stack, should we update x86-64 psABI to reflect what gcc really does? Thanks. -- H.J.