projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 8abee3ed KB |
1 | /*- |
| 2 | * Copyright (c) 1991 The Regents of the University of California. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * This code is derived from software contributed to Berkeley by | |
| 6 | * Ralph Campbell. | |
| 7 | * | |
| 8 | * %sccs.include.redist.c% | |
| 9 | */ | |
| 10 | ||
| 11 | #if defined(LIBC_SCCS) && !defined(lint) | |
| 12 | ASMSTR("@(#)ldexp.s 5.1 (Berkeley) %G%") | |
| 13 | #endif /* LIBC_SCCS and not lint */ | |
| 14 | ||
| 15 | #include "DEFS.h" | |
| 16 | ||
| 17 | .sdata | |
| 18 | infinity: | |
| 19 | .word 0x7ff00000 # IEEE infinity | |
| 20 | .text | |
| 21 | ||
| 22 | /* | |
| 23 | * double ldexp(val, exp) | |
| 24 | * returns: val * (2**exp), for integer exp | |
| 25 | */ | |
| 26 | LEAF(ldexp) | |
| 27 | .set noreorder | |
| 28 | mfc1 t0, $f13 | |
| 29 | mov.d $f0, $f12 | |
| 30 | sll t1, t0, 1 | |
| 31 | srl t1, t1, 21 | |
| 32 | addu t1, t1, a2 | |
| 33 | blez t1, 3f | |
| 34 | slti t2, t1, 2047 | |
| 35 | beq t2, zero, 2f | |
| 36 | sll a2, a2, 20 | |
| 37 | addu t0, t0, a2 | |
| 38 | mtc1 t0, $f1 | |
| 39 | 1: | |
| 40 | j ra | |
| 41 | nop | |
| 42 | 2: | |
| 43 | lwc1 $f1, infinity | |
| 44 | bgez t0, 1b | |
| 45 | mtc1 zero, $f0 | |
| 46 | j ra | |
| 47 | neg.d $f0, $f0 | |
| 48 | 3: | |
| 49 | blt t1, -51, 9f | |
| 50 | mfc1 t5, $f13 | |
| 51 | li t2, 0x80000000 | |
| 52 | sll t5, t5, 11 | |
| 53 | blt t1, -30, 7f | |
| 54 | or t5, t5, t2 | |
| 55 | srl t5, t5, 11 | |
| 56 | mfc1 t4, $f12 | |
| 57 | addiu t1, t1, -1 | |
| 58 | sll t3, t5, t1 | |
| 59 | srl t2, t4, t1 | |
| 60 | subu t1, zero, t1 | |
| 61 | srl t4, t4, t1 | |
| 62 | or t4, t4, t3 | |
| 63 | bgez t2, 6f | |
| 64 | srl t5, t5, t1 | |
| 65 | addiu t4, t4, 1 | |
| 66 | sltiu t6, t4, 1 | |
| 67 | sll t2, t2, 1 | |
| 68 | bne t2, zero, 6f | |
| 69 | addu t5, t5, t6 | |
| 70 | and t4, t4, ~1 | |
| 71 | 6: | |
| 72 | mtc1 t4, $f0 | |
| 73 | bgez t0, 1b | |
| 74 | mtc1 t5, $f1 | |
| 75 | j ra | |
| 76 | neg.d $f0, $f0 | |
| 77 | 7: | |
| 78 | mtc1 zero, $f1 | |
| 79 | addiu t1, t1, 20 | |
| 80 | sll t2, t5, t1 | |
| 81 | subu t1, zero, t1 | |
| 82 | bgez t2, 8f | |
| 83 | srl t4, t5, t1 | |
| 84 | addiu t4, t4, 1 | |
| 85 | sltiu t6, t4, 1 | |
| 86 | sll t2, t2, 1 | |
| 87 | bne t2, zero, 8f | |
| 88 | mtc1 t6, $f1 | |
| 89 | and t4, t4, ~1 | |
| 90 | 8: | |
| 91 | bgez t0, 1b | |
| 92 | mtc1 t4, $f0 | |
| 93 | j ra | |
| 94 | neg.d $f0, $f0 | |
| 95 | 9: | |
| 96 | mtc1 zero, $f0 | |
| 97 | bgez t0, 1b | |
| 98 | mtc1 zero, $f1 | |
| 99 | j ra | |
| 100 | neg.d $f0, $f0 | |
| 101 | .set reorder | |
| 102 | END(ldexp) |