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| Commit | Line | Data |
|---|---|---|
| b3162c13 SL |
1 | |
| 2 | #include "fp.h" | |
| 3 | #include "fp_in_krnl.h" | |
| 4 | ||
| 5 | ||
| 6 | # here we count from 0 not from 1 as in fp.h | |
| 7 | #define HIDDEN 23 | |
| 8 | ||
| 9 | .text | |
| 10 | .globl _Kdivd # _Kdivd(acc_most,acc_least,op_most,op_least,hfs) | |
| 11 | _Kdivd: .word 0xffc | |
| 12 | clrl r3 # r3 - sign: 0 for positive,1 for negative. | |
| 13 | movl 4(fp),r0 | |
| 14 | jgeq 1f | |
| 15 | movl $1,r3 | |
| 16 | 1: movl 12(fp),r2 | |
| 17 | jgeq 2f | |
| 18 | bbc $0,r3,1f # seconed operand is negative. | |
| 19 | clrl r3 # if first was negative, make result positive. | |
| 20 | jmp 2f | |
| 21 | 1: movl $1,r3 # if first was positive, make result negative. | |
| 22 | 2: andl2 $EXPMASK,r0 # compute first 'pure'exponent. | |
| 23 | jeql retz | |
| 24 | shrl $EXPSHIFT,r0,r0 | |
| 25 | subl2 $BIAS,r0 | |
| 26 | andl2 $EXPMASK,r2 # compute seconed 'pure'exponent. | |
| 27 | jeql retz2 | |
| 28 | shrl $EXPSHIFT,r2,r2 | |
| 29 | subl2 $BIAS,r2 | |
| 30 | subl3 r2,r0,r2 # subtruct the exponents. | |
| 31 | addl2 $BIAS,r2 | |
| 32 | jleq underf | |
| 33 | # normalization can make the exp. smaller. | |
| 34 | # | |
| 35 | # We have the sign in r3,the exponent in r2,now is the time to | |
| 36 | # perform the division... | |
| 37 | # | |
| 38 | # fetch dividend. (r4,r5) | |
| 39 | andl3 $(0!(EXPMASK | SIGNBIT)),4(fp),r4 | |
| 40 | orl2 $(0!CLEARHID),r4 | |
| 41 | movl 8(fp),r5 | |
| 42 | ||
| 43 | # fetch divisor : (r6,r7) | |
| 44 | andl3 $(0!(EXPMASK | SIGNBIT)),12(fp),r6 | |
| 45 | orl2 $(0!CLEARHID),r6 | |
| 46 | movl 16(fp),r7 | |
| 47 | ||
| 48 | movl $0,r0 # init r0,r1 to be zeros | |
| 49 | movl $0,r1 | |
| 50 | movl $(0!CLEARHID),r8# r8 first bit to set (if). | |
| 51 | shll $1,r8,r8 # to have one more bit,because we might | |
| 52 | # have to shift left to normelize. | |
| 53 | movl $0,r9 | |
| 54 | ||
| 55 | 2: | |
| 56 | subl2 r7,r5 | |
| 57 | sbwc r6,r4 | |
| 58 | jgeq 1f | |
| 59 | addl2 r7,r5 | |
| 60 | adwc r6,r4 | |
| 61 | shlq $1,r4,r4 | |
| 62 | shrq $1,r8,r8 | |
| 63 | jeql over | |
| 64 | jmp 2b | |
| 65 | 1: | |
| 66 | orl2 r8,r0 | |
| 67 | orl2 r9,r1 | |
| 68 | shlq $1,r4,r4 | |
| 69 | shrq $1,r8,r8 | |
| 70 | jneq 2b | |
| 71 | ||
| 72 | over: | |
| 73 | pushl 20(fp) | |
| 74 | callf $8,Kfnorm | |
| 75 | sign: | |
| 76 | 1: bbc $0,r3,done | |
| 77 | orl2 $SIGNBIT,r0 | |
| 78 | done: ret | |
| 79 | ||
| 80 | retz: | |
| 81 | clrl r0 | |
| 82 | clrl r1 | |
| 83 | ret | |
| 84 | ||
| 85 | retz2: bbc $31,12(fp),z_div | |
| 86 | clrl r0 | |
| 87 | clrl r1 | |
| 88 | ret | |
| 89 | underf: | |
| 90 | orl2 $HFS_UNDF,*20(fp) | |
| 91 | ret | |
| 92 | z_div: | |
| 93 | orl2 $HFS_DIVZ,*20(fp) | |
| 94 | ret |