1# 2# $NetBSD: ilsp.doc,v 1.1 2000/04/14 20:24:39 is Exp $ 3# 4 5#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 6# MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP 7# M68000 Hi-Performance Microprocessor Division 8# M68060 Software Package Production Release 9# 10# M68060 Software Package Copyright (C) 1993, 1994, 1995, 1996 Motorola Inc. 11# All rights reserved. 12# 13# THE SOFTWARE is provided on an "AS IS" basis and without warranty. 14# To the maximum extent permitted by applicable law, 15# MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED, 16# INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS 17# FOR A PARTICULAR PURPOSE and any warranty against infringement with 18# regard to the SOFTWARE (INCLUDING ANY MODIFIED VERSIONS THEREOF) 19# and any accompanying written materials. 20# 21# To the maximum extent permitted by applicable law, 22# IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER 23# (INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS PROFITS, 24# BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR OTHER PECUNIARY LOSS) 25# ARISING OF THE USE OR INABILITY TO USE THE SOFTWARE. 26# 27# Motorola assumes no responsibility for the maintenance and support 28# of the SOFTWARE. 29# 30# You are hereby granted a copyright license to use, modify, and distribute the 31# SOFTWARE so long as this entire notice is retained without alteration 32# in any modified and/or redistributed versions, and that such modified 33# versions are clearly identified as such. 34# No licenses are granted by implication, estoppel or otherwise under any 35# patents or trademarks of Motorola, Inc. 36#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 37 3868060 INTEGER SOFTWARE PACKAGE (Library version) 39------------------------------------------------- 40 41The file ilsp.s contains the "Library version" of the 4268060 Integer Software Package. Routines included in this 43module can be used to emulate 64-bit divide and multiply, 44and the "cmp2" instruction. These instructions are not 45implemented in hardware on the 68060 and normally take 46exception vector #61 "Unimplemented Integer Instruction". 47 48By re-compiling a program that uses these instructions, and 49making subroutine calls in place of the unimplemented 50instructions, a program can avoid the overhead associated with 51taking the exception. 52 53Release file format: 54-------------------- 55The file ilsp.sa is essentially a hexadecimal image of the 56release package. This is the ONLY format which will be supported. 57The hex image was created by assembling the source code and 58then converting the resulting binary output image into an 59ASCII text file. The hexadecimal numbers are listed 60using the Motorola Assembly Syntax assembler directive "dc.l" 61(define constant longword). The file can be converted to other 62assembly syntaxes by using any word processor with a global 63search and replace function. 64 65To assist in assembling and linking this module with other modules, 66the installer should add a symbolic label to the top of the file. 67This will allow calling routines to access the entry points 68of this package. 69 70The source code ilsp.s has also been included but only for 71documentation purposes. 72 73Release file structure: 74----------------------- 75The file ilsp.sa contains an "Entry-Point" section and a 76code section. The ILSP has no "Call-Out" section. The first section 77is the "Entry-Point" section. In order to access a function in the 78package, a program must "bsr" or "jsr" to the location listed 79below in "68060ILSP Entry Points" that corresponds to the desired 80function. A branch instruction located at the selected entry point 81within the package will then enter the correct emulation code routine. 82 83The entry point addresses at the beginning of the package will remain 84fixed so that a program calling the routines will not have to be 85re-compiled with every new 68060ILSP release. 86 87For example, to use a 64-bit multiply instruction, 88do a "bsr" or "jsr" to the entry point defined by 89the 060ILSP entry table. A compiler generated code sequence 90for unsigned multiply could look like: 91 92# mulu.l <ea>,Dh:Dl 93# mulu.l _multiplier,%d1:%d0 94 95 subq.l &0x8,%sp # make room for result on stack 96 pea (%sp) # pass: result addr on stack 97 mov.l %d0,-(%sp) # pass: multiplicand on stack 98 mov.l _multiplier,-(%sp) # pass: multiplier on stack 99 bsr.l _060LISP_TOP+0x18 # branch to multiply routine 100 add.l &0xc,%sp # clear arguments from stack 101 mov.l (%sp)+,%d1 # load result[63:32] 102 mov.l (%sp)+,%d0 # load result[31:0] 103 104For a divide: 105 106# divu.l <ea>,Dr:Dq 107# divu.l _divisor,%d1:%d0 108 109 subq.l &0x8,%sp # make room for result on stack 110 pea (%sp) # pass: result addr on stack 111 mov.l %d0,-(%sp) # pass: dividend hi on stack 112 mov.l %d1,-(%sp) # pass: dividend hi on stack 113 mov.l _divisor,-(%sp) # pass: divisor on stack 114 bsr.l _060LISP_TOP+0x08 # branch to divide routine 115 add.l &0xc,%sp # clear arguments from stack 116 mov.l (%sp)+,%d1 # load remainder 117 mov.l (%sp)+,%d0 # load quotient 118 119The library routines also return the correct condition code 120register value. If this is important, then the caller of the library 121routine must make sure that the value isn't lost while popping 122other items off of the stack. 123 124An example of using the "cmp2" instruction is as follows: 125 126# cmp2.l <ea>,Rn 127# cmp2.l _bounds,%d0 128 129 pea _bounds # pass ptr to bounds 130 mov.l %d0,-(%sp) # pass Rn 131 bsr.l _060LSP_TOP_+0x48 # branch to "cmp2" routine 132 mov.w %cc,_tmp # save off condition codes 133 addq.l &0x8,%sp # clear arguments from stack 134 135Exception reporting: 136-------------------- 137If the instruction being emulated is a divide and the source 138operand is a zero, then the library routine, as it's last 139instruction, executes an implemented divide using a zero 140source operand so that an "Integer Divide-by-Zero" exception 141will be taken. Although the exception stack frame will not 142point to the correct instruction, the user will at least be able 143to record that such an event occurred if desired. 144 14568060ILSP entry points: 146----------------------- 147_060ILSP_TOP: 1480x000: _060LSP__idivs64_ 1490x008: _060LSP__idivu64_ 150 1510x010: _060LSP__imuls64_ 1520x018: _060LSP__imulu64_ 153 1540x020: _060LSP__cmp2_Ab_ 1550x028: _060LSP__cmp2_Aw_ 1560x030: _060LSP__cmp2_Al_ 1570x038: _060LSP__cmp2_Db_ 1580x040: _060LSP__cmp2_Dw_ 1590x048: _060LSP__cmp2_Dl_ 160