diff options
Diffstat (limited to 'bitint.c')
| -rw-r--r-- | bitint.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/bitint.c b/bitint.c new file mode 100644 index 0000000..bf2b559 --- /dev/null +++ b/bitint.c @@ -0,0 +1,48 @@ +#include <stdio.h> +#include "c23-fallback.h" + +#ifndef BITINT_MAXWIDTH +# error "no _BitInt support found, aborting compilation" +// shut off some subsequent error messages +# include "no _BitInt support found, aborting compilation" +#endif + +int main (int argc, char* argv[static argc+1]) { + // this doesn't fit, diagnose? + _BitInt(15) s15 = 0b1010101'01010101wb; + unsigned _BitInt(15) u15 = 0b1010101'01010101wbu; + // this doesn't fit, diagnose? + _BitInt(15) su15 = u15; + + auto u65 = 0x1'FFFF'FFFF'FFFF'FFFFwbu; + // wrap around arithmetic is fine. + auto oa65 = 0x1'FFFF'FFFF'FFFF'FFFFwbu + 1wbu; + // constant too wide, diagnostic? + typeof(u65) o65 = 0x2'FFFF'FFFF'FFFF'FFFFwbu; + + auto s65 = 0xFFFF'FFFF'FFFF'FFFFwb; + // signed arithmetic overflows, diagnostic? + auto sa65 = 0xFFFF'FFFF'FFFF'FFFFwb + 1wb; + // constant too wide, diagnostic? + typeof(s65) os65 = 0x1'FFFF'FFFF'FFFF'FFFFwb; + + unsigned _BitInt(128) max128s = 0x7FFF'FFFF'FFFF'FFFF'FFFF'FFFF'FFFF'FFFFwb; + unsigned _BitInt(128) min128s = -1wb -max128s; + + unsigned _BitInt(3) max3u = -1; + unsigned _BitInt(4) max4u = -1; + unsigned _BitInt(4) one4u = max4u - max3u; + signed _BitInt(4) max4s = max3u; + signed _BitInt(4) min4s = ~max4s; + + printf("15 bits, signed:\t%d\n", (signed)s15); + printf("15 bits, unsigned:\t%u\n", (unsigned)u15); + printf("15 bits, u → s:\t%d\n", (signed)su15); + printf("4 bits:\t%u\n", (unsigned)max4u); + printf("4 bits:\t%u\n", (unsigned)one4u); + printf("4 bits:\t%d\n", (signed)max4s); + printf("4 bits:\t%d\n", (signed)min4s); + printf("4 bit arithm:\t%u\n", (unsigned)(max4u + 1wbu)); + printf("int arithm:\t%u\n", (unsigned)(max4u + 1)); + return s15 + su15 + u15 + u65 + oa65 + o65 + s65 + sa65 + os65 + !max128s + !min128s; +} |