GCC：哪些目标支持定点类型？

Question

$ echo "_Fract x;" | gcc -xc -
<stdin>:1:1: error: fixed-point types not supported for this target

6.16 Fixed-Point Types（强调）：

As an extension, GNU C supports fixed-point types as defined in the N1169 draft of ISO/IEC DTR 18037. Support for fixed-point types in GCC will evolve as the draft technical report changes. Calling conventions for any target might also change. Not all targets support fixed-point types.

问题：哪些目标支持定点类型？

额外：有记录吗？如何从GCC的源代码中导出？

更新。可能有用：Clang 确实通过选项 -ffixed-point:

支持定点类型

$ echo "_Fract x;" | clang -xc - -c -ffixed-point
# OK

Answer 1

我可以确认 GCC 11.2.0 在 AVR 上确实支持 fixed-point 类型。尺码为：

sizeof(signed   short _Fract) == 1
sizeof(unsigned short _Fract) == 1

sizeof(signed   _Fract) == 2
sizeof(unsigned _Fract) == 2

sizeof(signed   long _Fract) == 4
sizeof(unsigned long _Fract) == 4

sizeof(signed   long long _Fract) == 8
sizeof(unsigned long long _Fract) == 8

sizeof(signed   short _Accum) == 2
sizeof(unsigned short _Accum) == 2

sizeof(signed   _Accum) == 4
sizeof(unsigned _Accum) == 4

sizeof(signed   long _Accum) == 8
sizeof(unsigned long _Accum) == 8

sizeof(signed   long long _Accum) == 8
sizeof(unsigned long long _Accum) == 8

GCC：哪些目标支持定点类型？

GCC: which targets support fixed-point types?

c

gcc

fixed-point