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author | Mattias Andrée <maandree@member.fsf.org> | 2015-12-20 14:31:40 +0100 |
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committer | Mattias Andrée <maandree@member.fsf.org> | 2015-12-20 14:31:40 +0100 |
commit | 679b8bdb5c40ca1909b025db10ddb5a98967c60e (patch) | |
tree | f0c051e0569138a5c292e30892001604b65f851f /gen/bits | |
parent | fix issue #8 on github (diff) | |
download | slibc-679b8bdb5c40ca1909b025db10ddb5a98967c60e.tar.gz slibc-679b8bdb5c40ca1909b025db10ddb5a98967c60e.tar.bz2 slibc-679b8bdb5c40ca1909b025db10ddb5a98967c60e.tar.xz |
optimise implementations of {hton,ntoh}{s,l,ll}
Signed-off-by: Mattias Andrée <maandree@member.fsf.org>
Diffstat (limited to 'gen/bits')
-rw-r--r-- | gen/bits/intconf.c | 82 | ||||
-rw-r--r-- | gen/bits/intconf.h | 18 |
2 files changed, 100 insertions, 0 deletions
diff --git a/gen/bits/intconf.c b/gen/bits/intconf.c index 5a52d12..361dd16 100644 --- a/gen/bits/intconf.c +++ b/gen/bits/intconf.c @@ -140,6 +140,82 @@ static int fast(int bits) /** + * For a 16-bit integer with the value 0x0102, print, + * to a string, the bytes it is constructed by one the + * host machine, in storage order. + * + * @return The bytes in the integer juxtaposed. + */ +static char* byteorder_16(void) +{ + static char buf[16 / 4 + 1]; + union + { + short int all; + struct + { + char a; char b; + }; + } test = { .all = 0x0102 }; + + sprintf(buf, "%02i%02i", test.a, test.b); + return buf; +} + + +/** + * For a 32-bit integer with the value 0x01020304, print, + * to a string, the bytes it is constructed by one the + * host machine, in storage order. + * + * @return The bytes in the integer juxtaposed. + */ +static char* byteorder_32(void) +{ + static char buf[32 / 4 + 1]; + union + { + int all; + struct + { + char a; char b; char c; char d; + }; + } test = { .all = 0x01020304 }; + + sprintf(buf, "%02i%02i%02i%02i", + test.a, test.b, test.c, test.d); + return buf; +} + + +/** + * For a 16-bit integer with the value 0x0102030405060708, + * print, to a string, the bytes it is constructed by one + * the host machine, in storage order. + * + * @return The bytes in the integer juxtaposed. + */ +static char* byteorder_64(void) +{ + static char buf[64 / 4 + 1]; + union + { + long long int all; + struct + { + char a; char b; char c; char d; + char e; char f; char g; char h; + }; + } test = { .all = 0x0102030405060708LL }; + + sprintf(buf, "%02i%02i%02i%02i%02i%02i%02i%02i", + test.a, test.b, test.c, test.d, + test.e, test.f, test.g, test.h); + return buf; +} + + +/** * @param argc The number of command line arguments, should * be either 1 (print integer width information) * or 2 (otherwise). @@ -167,12 +243,18 @@ int main(int argc, char* argv[]) r |= printf("PTR_BIT %zu\n", 8 * sizeof(void*)); r |= printf("WCHAR_BIT %zu\n", 8 * sizeof(L'\0')); + /* Print byte orders. */ + r |= printf("INT16_BYTEORDER 0x%s\n", byteorder_16()); + r |= printf("INT32_BYTEORDER 0x%s\n", byteorder_32()); + r |= printf("INT64_BYTEORDER 0x%sLL\n", byteorder_64()); + /* Print the intrinsic type for specific numbers of bits. */ r |= printf("INT%zu %s\n", 8 * sizeof(char), "char"); r |= printf("INT%zu %s\n", 8 * sizeof(short int), "short int"); r |= printf("INT%zu %s\n", 8 * sizeof(int), "int"); r |= printf("INT%zu %s\n", 8 * sizeof(long int), "long int"); r |= printf("INT%zu %s\n", 8 * sizeof(long long int), "long long int"); + return r < 0 ? 1 : 0; } else if (argc == 2) diff --git a/gen/bits/intconf.h b/gen/bits/intconf.h index 69ea473..4d22435 100644 --- a/gen/bits/intconf.h +++ b/gen/bits/intconf.h @@ -97,6 +97,24 @@ #define __WCHAR_BIT //(bin/gen/bits/intconf | grep ^WCHAR_BIT | sed "s/^[^ ]* //") /** + * The 16-bit integer 0x0102 but with the + * bytes swapped to the storage order. + */ +#define __INT16_BYTEORDER //(bin/gen/bits/intconf | grep ^INT16_BYTEORDER | sed "s/^[^ ]* //") + +/** + * The 32-bit integer 0x01020304 but with + * the bytes swapped to the storage order. + */ +#define __INT32_BYTEORDER //(bin/gen/bits/intconf | grep ^INT32_BYTEORDER | sed "s/^[^ ]* //") + +/** + * The 64-bit integer 0x0102030405060708 but with + * the bytes swapped to the storage order. + */ +#define __INT64_BYTEORDER //(bin/gen/bits/intconf | grep ^INT64_BYTEORDER | sed "s/^[^ ]* //") + +/** * The underlaying intrinsic type for `int8_t` or `uint8_t`. */ #define __INT8 //(bin/gen/bits/intconf | grep ^INT8 | sed "s/^[^ ]* //" | sed 1q) |