/* * Copyright (c) 1986 Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * Computer Consoles Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #if defined(SYSLIBC_SCCS) && !defined(lint) .asciz "@(#)cvtuf.s 1.3 (Berkeley) 6/1/90" #endif /* SYSLIBC_SCCS and not lint */ #include #include "DEFS.h" XENTRY(cvtuf, R2|R3|R4|R5) # # Some initializations: # clrl r1 clrl r2 # r2 - exponent. movl 4(fp),r0 # fetch operand. jeql retzero # return zero. # # Compute exponent: # positive: ffs r0,r1 incl r1 addl2 r1,r2 shrl r1,r0,r0 jneq positive # look for more set bits. # # we have the exponent in r2. # movl 4(fp),r0 # r0 will hold the resulting f.p. number. # # Shift the fraction part to its proper place: # subl3 r2,$HID_POS,r3 jlss shiftr # if less then zero we have to shift right. shll r3,r0,r0 # else we shift left. jmp shifted shiftr: mnegl r3,r3 shrl r3,r0,r0 shifted: andl2 $CLEARHID,r0 # clear the hidden bit. shal $EXPSHIFT,r2,r2 # shift the exponent to its proper place. orl2 $EXPSIGN,r2 # set the exponent sign bit(to bias it). orl2 r2,r0 # combine exponent & fraction. sign_ok: ret retzero: clrl r0 ret