types: use int-ll64 for both aarch32 and aarch64
Since commit 031dbb12 ("AArch32: Add essential Arch helpers"), it is difficult to use consistent format strings for printf() family between aarch32 and aarch64. For example, uint64_t is defined as 'unsigned long long' for aarch32 and as 'unsigned long' for aarch64. Likewise, uintptr_t is defined as 'unsigned int' for aarch32, and as 'unsigned long' for aarch64. A problem typically arises when you use printf() in common code. One solution could be, to cast the arguments to a type long enough for both architectures. For example, if 'val' is uint64_t type, like this: printf("val = %llx\n", (unsigned long long)val); Or, somebody may suggest to use a macro provided by <inttypes.h>, like this: printf("val = %" PRIx64 "\n", val); But, both would make the code ugly. The solution adopted in Linux kernel is to use the same typedefs for all architectures. The fixed integer types in the kernel-space have been unified into int-ll64, like follows: typedef signed char int8_t; typedef unsigned char uint8_t; typedef signed short int16_t; typedef unsigned short uint16_t; typedef signed int int32_t; typedef unsigned int uint32_t; typedef signed long long int64_t; typedef unsigned long long uint64_t; [ Linux commit: 0c79a8e29b5fcbcbfd611daf9d500cfad8370fcf ] This gets along with the codebase shared between 32 bit and 64 bit, with the data model called ILP32, LP64, respectively. The width for primitive types is defined as follows: ILP32 LP64 int 32 32 long 32 64 long long 64 64 pointer 32 64 'long long' is 64 bit for both, so it is used for defining uint64_t. 'long' has the same width as pointer, so for uintptr_t. We still need an ifdef conditional for (s)size_t. All 64 bit architectures use "unsigned long" size_t, and most 32 bit architectures use "unsigned int" size_t. H8/300, S/390 are known as exceptions; they use "unsigned long" size_t despite their architecture is 32 bit. One idea for simplification might be to define size_t as 'unsigned long' across architectures, then forbid the use of "%z" string format. However, this would cause a distortion between size_t and sizeof() operator. We have unknowledge about the native type of sizeof(), so we need a guess of it anyway. I want the following formula to always return 1: __builtin_types_compatible_p(size_t, typeof(sizeof(int))) Fortunately, ARM is probably a majority case. As far as I know, all 32 bit ARM compilers use "unsigned int" size_t. Signed-off-by:Masahiro Yamada <yamada.masahiro@socionext.com>
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