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| Commit | Line | Data |
|---|---|---|
| 9d1834ba | 1 | /* Kcvtdl.s 1.3 86/01/05 */ |
| 2b252132 | 2 | |
| 9d1834ba SL |
3 | #include "../tahoemath/fp.h" |
| 4 | #include "../tahoemath/Kfp.h" | |
| 5 | #include "../tahoe/SYS.h" | |
| 5fd8ec52 | 6 | |
| 5fd8ec52 SL |
7 | |
| 8 | .text | |
| 9 | .globl _Kcvtdl | |
| 10 | .globl _Kcvtdu | |
| 11 | _Kcvtdu: | |
| 2b252132 SL |
12 | _Kcvtdl: |
| 13 | .word R5|R4|R3|R2 | |
| 5fd8ec52 SL |
14 | |
| 15 | # | |
| 16 | #Some initializations: | |
| 17 | # | |
| 18 | clrl r3 # r3 - negative flag. | |
| 19 | movl 4(fp),r0 # fetch operand. | |
| 20 | movl 8(fp),r1 | |
| 21 | # | |
| 22 | #get exponent | |
| 23 | # | |
| 24 | andl3 $EXPMASK,r0,r2 # r2 will hold the exponent. | |
| 25 | jeql retzero | |
| 26 | cmpl $TWO_EXP,r2 # if exponent is less then -2,return zero. | |
| 27 | jgtr retzero | |
| 28 | andl2 $0!EXPSIGN,r2 # turn off biased exponent sign | |
| 29 | shrl $EXPSHIFT,r2,r2 | |
| 30 | # | |
| 31 | #get fraction | |
| 32 | # | |
| 33 | bbc $31,r0,positive # if negative remember it. | |
| 34 | incl r3 | |
| 35 | positive: | |
| 36 | # clear the non fraction parts. | |
| 37 | andl2 $(0!(EXPMASK | SIGNBIT)),r0 | |
| 38 | # add the hidden bit. | |
| 39 | orl2 $(0!CLEARHID),r0 | |
| 40 | subl2 $24,r2 # compute the shift. | |
| 41 | jgtr shift_left | |
| 42 | mnegl r2,r2 | |
| 43 | shrl r2,r0,r0 # shift right. | |
| 44 | jmp shifted | |
| 45 | shift_left: | |
| 46 | cmpl r2,$7 | |
| 47 | jgtr overflow | |
| 48 | go_on: shlq r2,r0,r0 # shift right. | |
| 49 | shifted: | |
| 50 | bbc $0,r3,done # check for negative | |
| 51 | mnegl r0,r0 | |
| 52 | done: | |
| 53 | ret | |
| 54 | ||
| 55 | retzero: | |
| 56 | clrl r0 | |
| 57 | ret | |
| 58 | overflow: | |
| 59 | ret |