| #include <cstdint> |
| |
| struct alignas(16) float80_raw { |
| uint64_t mantissa; |
| uint16_t sign_exp; |
| }; |
| |
| int main() { |
| float80_raw st[] = { |
| {0x8000000000000000, 0x4000}, // +2.0 |
| {0x3f00000000000000, 0x0000}, // 1.654785e-4932 (denormal) |
| {0x0000000000000000, 0x0000}, // +0 |
| {0x0000000000000000, 0x8000}, // -0 |
| {0x8000000000000000, 0x7fff}, // +inf |
| {0x8000000000000000, 0xffff}, // -inf |
| {0xc000000000000000, 0xffff}, // nan |
| // st7 will be freed to test tag word better |
| {0x0000000000000000, 0x0000}, // +0 |
| }; |
| |
| // unmask divide-by-zero exception |
| uint16_t cw = 0x037b; |
| // used as single-precision float |
| uint32_t zero = 0; |
| |
| asm volatile( |
| "finit\n\t" |
| "fldcw %1\n\t" |
| // load on stack in reverse order to make the result easier to read |
| "fldt 0x70(%0)\n\t" |
| "fldt 0x60(%0)\n\t" |
| "fldt 0x50(%0)\n\t" |
| "fldt 0x40(%0)\n\t" |
| "fldt 0x30(%0)\n\t" |
| "fldt 0x20(%0)\n\t" |
| "fldt 0x10(%0)\n\t" |
| "fldt 0x00(%0)\n\t" |
| // free st7 |
| "ffree %%st(7)\n\t" |
| // this should trigger a divide-by-zero |
| "fdivs (%2)\n\t" |
| "int3\n\t" |
| : |
| : "a"(st), "m"(cw), "b"(&zero) |
| : "st" |
| ); |
| |
| return 0; |
| } |