| /* APPLE LOCAL file 5316398 improved float/double -> int64 functions */ |
| #include <stdint.h> |
| |
| int64_t |
| __fixsfdi (float x) |
| { |
| union { float f; uint32_t u; } u = {x}; |
| uint32_t fabsx = u.u & 0x7fffffffU; |
| uint32_t exp = fabsx >> 23; |
| int64_t result = 0; |
| |
| /* for small ints, overflow and NaN, the int32_t converter works fine |
| if( |x| < 0x1.0p31f || |x| >= 1.0p64f || isnan(x) ) unsigned |
| compare */ |
| if (exp - (127U + 31U) >= (63U - 31U)) |
| { |
| if (exp > (127 + 31)) |
| { |
| if (x == -0x1.0p63f) |
| return 0x8000000000000000LL; |
| |
| uint32_t r = (int32_t) x; |
| result = (int64_t) r << 32; |
| r = (r << 1) | (r & 1); |
| result |= r; |
| return result; |
| } |
| |
| /* small number. Regular int32_t conversion will work fine here. */ |
| result = (int32_t) x; |
| return result; |
| } |
| |
| /* 0x1.0p31 <= |x| <0x1.0p64, x is always an integer in this range */ |
| |
| /* convert float to fixed */ |
| result = (fabsx & 0x007fffffU) | 0x00800000; |
| |
| /* signMask = x < 0.0f ? -1LL : 0 */ |
| int64_t signMask = (int64_t) u.u << 32; |
| signMask >>= 63; |
| |
| /* Calculate shift value to move fixed point to right place */ |
| int32_t leftShift = exp - (127 + 23); |
| |
| /* move the fixed point into place */ |
| result <<= leftShift; |
| |
| /* Fix sign */ |
| result ^= signMask; |
| result -= signMask; |
| |
| return result; |
| } |
