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1.1 ! root 1: .data ! 2: .asciz "@(#)Fmuls.s 1.1 86/02/03 Copyr 1985 Sun Micro" ! 3: .even ! 4: .text ! 5: ! 6: | Copyright (c) 1985 by Sun Microsystems, Inc. ! 7: ! 8: #include "fpcrtdefs.h" ! 9: ! 10: /* ! 11: * ieee single floating multiply ! 12: * copyright 1981, 1982 Richard E. James III ! 13: * translated to SUN idiom 14 March 1983 rt ! 14: */ ! 15: ! 16: /* ! 17: * entry conditions: ! 18: * first argument in d0 ! 19: * second argument in d1 ! 20: * exit conditions: ! 21: * result (4 bytes) in d0 ! 22: * ! 23: * register conventions: ! 24: * d0 operand1/upper1 ! 25: * d1 operand2/upper2 ! 26: * d2 9/lower1 ! 27: * d3 lower2 ! 28: * d4 exponent ! 29: * d5 sign ! 30: */ ! 31: SAVEMASK = 0x3c00 | registers d2-d5 ! 32: RESTMASK = 0x3c ! 33: NSAVED = 6*4 | 6 registers * sizeof(register) ! 34: ! 35: RTENTRY(Fsqrs) ! 36: movel d0,d1 | Copy second argument. ! 37: bras Fmuls2 ! 38: RTENTRY(Fmuls) ! 39: | save registers ! 40: Fmuls2: ! 41: moveml #SAVEMASK,sp@- | registers d2-d7 ! 42: | save sign of result ! 43: movl d0,d5 ! 44: eorl d1,d5 | sign of result ! 45: asll #1,d0 | toss sign ! 46: asll #1,d1 | EEmmmm0 ! 47: cmpl d1,d0 ! 48: | order operands (exponents at least) ! 49: blss eswap ! 50: exg d0,d1 | d1 = larger ! 51: | extract and check exponents ! 52: eswap: roll #8,d0 ! 53: roll #8,d1 | mmmmm0ee ! 54: clrw d4 ! 55: movb d0,d4 ! 56: clrw d3 ! 57: movb d1,d3 ! 58: addw d3,d4 | result exp ! 59: cmpb #0xff, d1 ! 60: beqs ofl | infinity or nan ! 61: tstb d0 ! 62: beqs ufl | 0 or gu (denormalized) ! 63: | clear exponent; set hidden bit ! 64: movb #1,d0 ! 65: rorl #1,d0 ! 66: back: movb #1,d1 ! 67: rorl #1,d1 ! 68: ! 69: movl d0,d2 | d2 gets x. ! 70: movl d1,d3 | d3 gets y. ! 71: swap d0 | d0 gets xu. ! 72: swap d1 | d1 gets yu. ! 73: movw d1,d5 | d5 gets yu. ! 74: mulu d2,d1 | d1 gets xl*yu. ! 75: mulu d3,d2 | d2 gets xl*yl. ! 76: mulu d0,d3 | d3 gets xu*yl. ! 77: mulu d5,d0 | d0 gets xu*yu. ! 78: addl d3,d1 | d1 gets middle = xu*yl+xl*yu. ! 79: bccs 1$ | Branch if no carry occurred. ! 80: addl #0x10000,d0 | Propagate carry to upper product. ! 81: 1$: ! 82: swap d1 | d1 gets middle(m) (ml,mu). ! 83: clrl d3 ! 84: movw d1,d3 | d3 gets (0,mu). ! 85: clrw d1 | d1 gets (ml,0). ! 86: addl d2,d1 | d1 gets lower part of final product. ! 87: addxl d3,d0 | d0 gets upper part of final product. ! 88: tstl d1 ! 89: beqs 2$ | Branch if lower part is exact. ! 90: bset #0,d0 | Set sticky bit if lower part has bits. ! 91: 2$: ! 92: subw #126,d4 | toss extra bias ! 93: jbsr f_rcp | round check, pack ! 94: ! 95: | build answer ! 96: mbuild: rorl #8,d0 ! 97: roxll #1,d5 ! 98: roxrl #1,d0 | append sign ! 99: ! 100: | answer in d0 ! 101: mexit: moveml sp@+,#RESTMASK ! 102: RET ! 103: ! 104: | EXCEPTION HANDLING ! 105: ofl: clrb d1 ! 106: tstl d1 | larger mantissa ! 107: bnes mni | user larger nan ! 108: tstl d0 ! 109: beqs m_gennan | 0*inf ! 110: mni: movb #0xff,d1 | inf or nan ! 111: movl d1,d0 ! 112: bras mbuild ! 113: ufl: tstl d0 | mantissa of smaller ! 114: beqs mbuild ! 115: | normalizing mode is embodied int the next few lines: ! 116: bmis back ! 117: normden:subql #1,d4 | adj exponent ! 118: lsll #1,d0 ! 119: bpls normden ! 120: bras back ! 121: ! 122: m_gennan:movl #0x7f800002, d0 ! 123: bras mexit ! 124: ! 125: /* ! 126: * ieee single floating divide ! 127: * copyright 1981, Richard E. James III ! 128: * translated to SUN idiom 14 March 1983 rt ! 129: */ ! 130: ! 131: /* ! 132: * entry conditions: ! 133: * first argument in d0 ! 134: * second argument in d1 ! 135: * exit conditions: ! 136: * result (4 bytes) in d0 ! 137: * ! 138: * register conventions: ! 139: * d0 top; ab; rq ! 140: * d1 bot; c ! 141: * d2 q ! 142: * d3 bottom exp; d ! 143: * d4 top/ final exp ! 144: * d5 sign ! 145: */ ! 146: | ! 147: | same as for multiply, above ! 148: | SAVEMASK = 0x3c00 | registers d2-d5 ! 149: | RESTMASK = 0x3c ! 150: | NSAVED = 4*4 | 4 registers * sizeof(register) ! 151: ! 152: RTENTRY(Fdivs) ! 153: | save registers ! 154: moveml #SAVEMASK,sp@- | registers d2-d5 ! 155: | determine sign ! 156: movl d0,d5 ! 157: eorl d1,d5 | sign in bit 31 ! 158: | split out exponent ! 159: roll #1,d0 ! 160: roll #1,d1 ! 161: roll #8,d0 ! 162: roll #8,d1 ! 163: clrw d3 ! 164: clrw d4 ! 165: movb d0,d4 | exp of top ! 166: movb d1,d3 | exp of bottom ! 167: andw #0xfe00,d0 | clear out s, exp ! 168: andw #0xfe00,d1 | clear out s, exp ! 169: | test exponents ! 170: addqb #1,d4 | top ! 171: subqw #1,d4 ! 172: bles toperr ! 173: addqb #1,d0 | hidden bit ! 174: backtop:addqb #1,d3 ! 175: subqw #1,d3 | bottom ! 176: bles boterr ! 177: addqb #1,d1 | hidden bit ! 178: | position mantissas ! 179: backbot:rorl #2,d1 | 01X... ! 180: rorl #4,d0 | 0001X... ! 181: | compute tentative exponent ! 182: subw d3,d4 ! 183: | to compute ab/cd: ! 184: | first do ab/c -> q, remainder -> r ! 185: movw d1,d3 | save d ! 186: movw d3,d5 | d5 saves d. ! 187: swap d1 | get c ! 188: divu d1,d0 | ab/c 29/15->15 bits ! 189: movw d0,d2 | save q ! 190: mulu d2,d3 | q*d ! 191: clrw d0 | r in top ! 192: subl d3,d0 | r-q*d = +-31 ! 193: asrl #2,d0 | avoid ofl ! 194: divs d1,d0 | more quotient ! 195: movl d0,d1 | d1 gets remainder in upper word. ! 196: movw d5,d3 | d3 gets d. ! 197: muls d0,d3 | d3 gets signed(q2)*unsigned(d). ! 198: btst #15,d5 ! 199: beqs 99$ | Branch if d appeared positive in muls. ! 200: swap d3 | If d appeared negative, correct product. ! 201: addw d0,d3 ! 202: swap d3 ! 203: 99$: | ! 204: extl d2 | q ! 205: extl d0 | second quot ! 206: swap d2 ! 207: asll #2,d0 ! 208: addl d2,d0 ! 209: asll #1,d0 ! 210: clrw d1 | d1 gets remainder in upper, 0 lower. ! 211: subl d3,d1 | d1 gets revised remainder. ! 212: beqs adjexp | Branch if exact. ! 213: bmis decr | Branch if remainder negative. ! 214: bset #0,d0 | inexact => set sticky. ! 215: bras adjexp ! 216: decr: ! 217: subql #1,d0 | Subtract sticky bit for negative remainder. ! 218: ! 219: adjexp: | adjust exponent, round, check extremes, pack ! 220: addw #127,d4 ! 221: jbsr f_rcp ! 222: | reposition and append sign ! 223: drepk: rorl #8,d0 ! 224: lsll #1,d5 | sign -> x ! 225: roxrl #1,d0 | insert sign ! 226: dexit: moveml sp@+,#RESTMASK ! 227: RET ! 228: ! 229: | EXCEPTIONS ! 230: toperr: bnes 2$ ! 231: |top is 0 or gu, normalize and return ! 232: 1$: subqw #1,d4 ! 233: roll #1,d0 ! 234: bhis 1$ | loop til normalized, fall if 0 ! 235: addqw #1,d4 ! 236: bras backtop | 0 or gu ! 237: ! 238: | top is inf or nan ! 239: 2$: cmpb d3,d4 ! 240: beqs dinvop | both inf/nan -> nan ! 241: tstl d0 ! 242: beqs geninf | inf/ ... = +- inf ! 243: bras dinvop | nan/... = nan ! 244: ! 245: boterr: beqs botlow | .../(0|gu) ! 246: | .../(inf|nan) ! 247: tstl d1 ! 248: bnes dinvop | .../nan = nan ! 249: clrl d0 | .../inf = +-0 ! 250: bras drepk ! 251: botlow: tstl d1 ! 252: beqs 5$ | .../0 ! 253: | .../gu: ! 254: 4$: subqw #1,d3 ! 255: roll #1,d1 ! 256: bccs 4$ | loop til normalized ! 257: addqw #1,d3 ! 258: jra backbot ! 259: ! 260: | bottom is zero ! 261: 5$: tstl d0 ! 262: beqs d_gennan | 0/0 = nan ! 263: | nonzero/0 = +-inf ! 264: | generate infinity for answer ! 265: geninf: movl #0xff,d0 ! 266: bras drepk ! 267: ! 268: | invalid operand/ operation ! 269: dinvop: cmpl d0,d1 ! 270: bcss 8$ | use larger nan ! 271: tstl d1 ! 272: beqs d_gennan | both are infinity, generate a nan ! 273: exg d1,d0 | larger nan ! 274: 8$: lsrl #8,d0 ! 275: lsrl #1,d0 ! 276: bras bldnan | return nan ! 277: ! 278: d_gennan:moveq #4,d0 | nan 4 ! 279: bldnan: orl #0x7f800000,d0 ! 280: bras dexit ! 281: ! 282: SAVEMASK = 0x3f00 ! 283: RESTMASK = 0x00fc ! 284: ! 285: EXP = d2 ! 286: TYPE = d3 ! 287: /* type values: */ ! 288: ZERO = 1 | wonderful ! 289: GU = 2 ! 290: PLAIN = 3 ! 291: INF = 4 ! 292: NAN = 5 ! 293: ! 294: RTENTRY(Fscaleis) ! 295: moveml #SAVEMASK,sp@- | state save ! 296: movel d1,d4 | Save argument i. ! 297: movel d0,d1 | What a crock! ! 298: jbsr f_unpk ! 299: cmpb #PLAIN,TYPE | is it a funny number? ! 300: bgts gohome | yes -- return argument ! 301: cmpb #ZERO,TYPE ! 302: beqs gohome | is zero -- return arg ! 303: | normal path through here ! 304: movw EXP,d7 ! 305: extl d7 | d7 gets long exponent. ! 306: addl d4,d7 | d7 gets modified exponent. ! 307: bvcs nooflo | Branch if no overflow. ! 308: bmis posov | Branch if positive overflow to -. ! 309: | Branch if negative overflow to +. ! 310: negov: ! 311: movw #-2000,EXP ! 312: bras gohome ! 313: posov: ! 314: movw #2000,EXP ! 315: bras gohome ! 316: nooflo: ! 317: cmpl #2000,d7 ! 318: bges posov ! 319: cmpl #-2000,d7 ! 320: bles negov ! 321: movw d7,EXP | Final OK exponent. ! 322: gohome: ! 323: jbsr f_pack ! 324: movel d1,d0 | What a crock! ! 325: gone: moveml sp@+,#RESTMASK ! 326: RET
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