Edward O'Callaghan | 37a6a45 | 2009-08-07 20:30:09 +0000 | [diff] [blame] | 1 | /* ===-- fixdfdi.c - Implement __fixdfdi -----------------------------------=== |
| 2 | * |
| 3 | * The LLVM Compiler Infrastructure |
| 4 | * |
Howard Hinnant | 9ad441f | 2010-11-16 22:13:33 +0000 | [diff] [blame] | 5 | * This file is dual licensed under the MIT and the University of Illinois Open |
| 6 | * Source Licenses. See LICENSE.TXT for details. |
Edward O'Callaghan | 37a6a45 | 2009-08-07 20:30:09 +0000 | [diff] [blame] | 7 | * |
| 8 | * ===----------------------------------------------------------------------=== |
| 9 | * |
| 10 | * This file implements __fixdfdi for the compiler_rt library. |
| 11 | * |
| 12 | * ===----------------------------------------------------------------------=== |
| 13 | */ |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 14 | |
| 15 | #include "int_lib.h" |
| 16 | |
Edward O'Callaghan | 37a6a45 | 2009-08-07 20:30:09 +0000 | [diff] [blame] | 17 | /* Returns: convert a to a signed long long, rounding toward zero. */ |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 18 | |
Edward O'Callaghan | 37a6a45 | 2009-08-07 20:30:09 +0000 | [diff] [blame] | 19 | /* Assumption: double is a IEEE 64 bit floating point type |
| 20 | * su_int is a 32 bit integral type |
| 21 | * value in double is representable in di_int (no range checking performed) |
| 22 | */ |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 23 | |
Edward O'Callaghan | 37a6a45 | 2009-08-07 20:30:09 +0000 | [diff] [blame] | 24 | /* seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm */ |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 25 | |
Chandler Carruth | 0193b74 | 2012-06-22 21:09:15 +0000 | [diff] [blame] | 26 | ARM_EABI_FNALIAS(d2lz, fixdfdi) |
Anton Korobeynikov | 37b97d1 | 2011-04-19 17:51:24 +0000 | [diff] [blame] | 27 | |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 28 | di_int |
| 29 | __fixdfdi(double a) |
| 30 | { |
| 31 | double_bits fb; |
| 32 | fb.f = a; |
Edward O'Callaghan | 8bf1e09 | 2009-08-09 18:41:02 +0000 | [diff] [blame] | 33 | int e = ((fb.u.s.high & 0x7FF00000) >> 20) - 1023; |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 34 | if (e < 0) |
| 35 | return 0; |
Edward O'Callaghan | 8bf1e09 | 2009-08-09 18:41:02 +0000 | [diff] [blame] | 36 | di_int s = (si_int)(fb.u.s.high & 0x80000000) >> 31; |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 37 | dwords r; |
Edward O'Callaghan | 8bf1e09 | 2009-08-09 18:41:02 +0000 | [diff] [blame] | 38 | r.s.high = (fb.u.s.high & 0x000FFFFF) | 0x00100000; |
| 39 | r.s.low = fb.u.s.low; |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 40 | if (e > 52) |
| 41 | r.all <<= (e - 52); |
| 42 | else |
| 43 | r.all >>= (52 - e); |
| 44 | return (r.all ^ s) - s; |
Edward O'Callaghan | 37a6a45 | 2009-08-07 20:30:09 +0000 | [diff] [blame] | 45 | } |