------- Comment #4 from hjl dot tools at gmail dot com 2009-12-07 19:41 ------- We have 3 options:
1. Keep the psABI ASIS and fix gcc. But zero out upper 32bits of 64bits for _Bool on stack doesn't make any sense. 2. Remove that paragraph in the psABI and keep gcc ASIS. It will make _Bool consistent independent of if it is used for function parameters. Both gcc and icc always treat _Bool as char even if it is returned from a function. It may break compatibilities among x86-64 compilers. But we have such problems anyway for gcc 4.3 and 4.4. 3. Changes the psABI to zero out 1-31bits. When _Bool is returned from function, upper 63bits will be zeroed out due to x86-64 architecture. But on stack, we only need to zero out 1-31bits. Even if we do this, we still can't treat _Bool as long long when returned from a function since it will break with object files compiled with gcc 4.3/4.4. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42324
