1*25693Ssam/* Kmodf.s 1.3 86/01/05 */ 224141Ssam 3*25693Ssam#include "../tahoe/SYS.h" 4*25693Ssam#include "../tahoemath/fp.h" 524141Ssam 624141Ssam/* 725664Ssam * float Kmodf (value, iptr, hfs) 825664Ssam * float value, *iptr; 925664Ssam * int hfs; 1025664Ssam * 1125664Ssam * Modf returns the fractional part of "value", 1225664Ssam * and stores the integer part indirectly through "iptr". 1325664Ssam */ 1424141Ssam .text 1525664SsamENTRY(Kmodf, R8|R7|R6|R5|R4|R3|R2) 1624141Ssam /* 1724141Ssam * Some initializations: 1824141Ssam */ 1924141Ssam clrl r3 2024141Ssam movl 4(fp),r0 /* fetch operand to r0. */ 2124141Ssam movl 8(fp),r1 2224141Ssam movl 12(fp),r6 /* fetch addr of int to r6. */ 2324141Ssam /* 2425664Ssam * get exponent 2525664Ssam */ 2624141Ssam andl3 $EXPMASK,r0,r2 /* r2 will hold the exponent. */ 2724141Ssam shrl $EXPSHIFT,r2,r2 2824141Ssam subl2 $BIAS,r2 /* unbias it. */ 2924141Ssam jleq allfrac /* it's int part is zero. */ 3024141Ssam cmpl r2,$56 3124141Ssam jgeq allint /* it's fraction part is zero. */ 3224141Ssam /* 3325664Ssam * get fraction 3425664Ssam */ 3524141Ssam movl r0,r4 /* remember the original number. */ 3624141Ssam movl r1,r5 3724141Ssam bbc $31,r0,positive /* if negative remember it. */ 3824141Ssam incl r3 3924141Ssampositive: 4024141Ssam /* clear the non fraction parts. */ 4124141Ssam andl2 $(0!(EXPMASK | SIGNBIT)),r0 4224141Ssam /* add the hidden bit. */ 4324141Ssam orl2 $(0!CLEARHID),r0 4424141Ssam 4524141Ssam cmpl r2,$HID_POS /* see if there are bits to clear only in r0 */ 4624141Ssam jgtr in_r1 /* some bytes in r1 */ 4724141Ssam jeql onlyallr0 /* all r0 must be cleared. */ 4824141Ssam mnegl r2,r7 /* r7 - loop counter. */ 4924141Ssam movl $CLEARHID,r8 /* first bit to clear. */ 5024141Ssam1: 5124141Ssam andl2 r8,r0 /* clear int. bits from fraction part. */ 5224141Ssam shar $1,r8,r8 5324141Ssam aoblss $0,r7,1b 5424141Ssam1: 5524141Ssam andl2 r8,r4 /* clear frac bits for int calculation: */ 5624141Ssam shar $1,r8,r8 5724141Ssam cmpl $0xffffffff,r8 5824141Ssam jneq 1b 5924141Ssam clrl r5 6024141Ssam jmp norm 6124141Ssam 6224141Ssamonlyallr0: 6324141Ssam clrl r0 6424141Ssam clrl r5 6524141Ssam jmp norm 6624141Ssam 6724141Ssamin_r1: 6824141Ssam clrl r0 6924141Ssam subl3 r2,$HID_POS,r7 7024141Ssam movl $0x7fffffff,r8 7124141Ssam1: 7224141Ssam andl2 r8,r1 7324141Ssam shar $1,r8,r8 7424141Ssam orl2 $0x80000000,r8 7524141Ssam aoblss $0,r7,1b 7624141Ssam1: 7724141Ssam andl2 r8,r5 7824141Ssam shar $1,r8,r8 7924141Ssam cmpl $0xffffffff,r8 8024141Ssam jneq 1b 8124141Ssamnorm: 8224141Ssam addl2 $BIAS,r2 /* fnorm expects it biased. */ 8324141Ssam pushl 16(fp) /* hfs */ 8425664Ssam callf $8,_Kfnorm /* normelize fraction part. */ 8524141Ssam cmpl $0,r0 8624141Ssam jeql 1f 8724141Ssam bbc $0,r3,1f 8824141Ssam orl2 $0x80000000,r0 8924141Ssam1: 9024141Ssam movl r4,(r6) /* put int part in place. */ 9124141Ssam movl r5,4(r6) 9224141Ssam ret 9324141Ssam 9424141Ssamallint: 9524141Ssam movl r0,(r6) /* copy the argument to the int addr. */ 9624141Ssam movl r1,4(r6) 9724141Ssam clrl r0 /* clear the fraction part. */ 9824141Ssam clrl r1 9924141Ssam ret 10024141Ssam 10124141Ssamallfrac: 10224141Ssam /* the fraction is ready in r0. */ 10324141Ssam clrl (r6) /* zero the int part. */ 10424141Ssam clrl 4(r6) 10524141Ssam ret 10624141Ssam 10724141Ssamret_zero: 10824141Ssam clrl (r6) 10924141Ssam clrl 4(r6) 11024141Ssam clrl r0 11124141Ssam clrl r1 11224141Ssam ret 113