ilsp.doc (6107B)
1~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 2MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP 3M68000 Hi-Performance Microprocessor Division 4M68060 Software Package 5Production Release P1.00 -- October 10, 1994 6 7M68060 Software Package Copyright © 1993, 1994 Motorola Inc. All rights reserved. 8 9THE SOFTWARE is provided on an "AS IS" basis and without warranty. 10To the maximum extent permitted by applicable law, 11MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED, 12INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE 13and any warranty against infringement with regard to the SOFTWARE 14(INCLUDING ANY MODIFIED VERSIONS THEREOF) and any accompanying written materials. 15 16To the maximum extent permitted by applicable law, 17IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER 18(INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS PROFITS, 19BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR OTHER PECUNIARY LOSS) 20ARISING OF THE USE OR INABILITY TO USE THE SOFTWARE. 21Motorola assumes no responsibility for the maintenance and support of the SOFTWARE. 22 23You are hereby granted a copyright license to use, modify, and distribute the SOFTWARE 24so long as this entire notice is retained without alteration in any modified and/or 25redistributed versions, and that such modified versions are clearly identified as such. 26No licenses are granted by implication, estoppel or otherwise under any patents 27or trademarks of Motorola, Inc. 28~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 2968060 INTEGER SOFTWARE PACKAGE (Library version) 30------------------------------------------------- 31 32The file ilsp.s contains the "Library version" of the 3368060 Integer Software Package. Routines included in this 34module can be used to emulate 64-bit divide and multiply, 35and the "cmp2" instruction. These instructions are not 36implemented in hardware on the 68060 and normally take 37exception vector #61 "Unimplemented Integer Instruction". 38 39By re-compiling a program that uses these instructions, and 40making subroutine calls in place of the unimplemented 41instructions, a program can avoid the overhead associated with 42taking the exception. 43 44Release file format: 45-------------------- 46The file ilsp.sa is essentially a hexadecimal image of the 47release package. This is the ONLY format which will be supported. 48The hex image was created by assembling the source code and 49then converting the resulting binary output image into an 50ASCII text file. The hexadecimal numbers are listed 51using the Motorola Assembly Syntax assembler directive "dc.l" 52(define constant longword). The file can be converted to other 53assembly syntaxes by using any word processor with a global 54search and replace function. 55 56To assist in assembling and linking this module with other modules, 57the installer should add a symbolic label to the top of the file. 58This will allow calling routines to access the entry points 59of this package. 60 61The source code ilsp.s has also been included but only for 62documentation purposes. 63 64Release file structure: 65----------------------- 66The file ilsp.sa contains an "Entry-Point" section and a 67code section. The ILSP has no "Call-Out" section. The first section 68is the "Entry-Point" section. In order to access a function in the 69package, a program must "bsr" or "jsr" to the location listed 70below in "68060ILSP Entry Points" that corresponds to the desired 71function. A branch instruction located at the selected entry point 72within the package will then enter the correct emulation code routine. 73 74The entry point addresses at the beginning of the package will remain 75fixed so that a program calling the routines will not have to be 76re-compiled with every new 68060ILSP release. 77 78For example, to use a 64-bit multiply instruction, 79do a "bsr" or "jsr" to the entry point defined by 80the 060ILSP entry table. A compiler generated code sequence 81for unsigned multiply could look like: 82 83# mulu.l <ea>,Dh:Dl 84# mulu.l _multiplier,%d1:%d0 85 86 subq.l &0x8,%sp # make room for result on stack 87 pea (%sp) # pass: result addr on stack 88 mov.l %d0,-(%sp) # pass: multiplicand on stack 89 mov.l _multiplier,-(%sp) # pass: multiplier on stack 90 bsr.l _060LISP_TOP+0x18 # branch to multiply routine 91 add.l &0xc,%sp # clear arguments from stack 92 mov.l (%sp)+,%d1 # load result[63:32] 93 mov.l (%sp)+,%d0 # load result[31:0] 94 95For a divide: 96 97# divu.l <ea>,Dr:Dq 98# divu.l _divisor,%d1:%d0 99 100 subq.l &0x8,%sp # make room for result on stack 101 pea (%sp) # pass: result addr on stack 102 mov.l %d0,-(%sp) # pass: dividend hi on stack 103 mov.l %d1,-(%sp) # pass: dividend hi on stack 104 mov.l _divisor,-(%sp) # pass: divisor on stack 105 bsr.l _060LISP_TOP+0x08 # branch to divide routine 106 add.l &0xc,%sp # clear arguments from stack 107 mov.l (%sp)+,%d1 # load remainder 108 mov.l (%sp)+,%d0 # load quotient 109 110The library routines also return the correct condition code 111register value. If this is important, then the caller of the library 112routine must make sure that the value isn't lost while popping 113other items off of the stack. 114 115An example of using the "cmp2" instruction is as follows: 116 117# cmp2.l <ea>,Rn 118# cmp2.l _bounds,%d0 119 120 pea _bounds # pass ptr to bounds 121 mov.l %d0,-(%sp) # pass Rn 122 bsr.l _060LSP_TOP_+0x48 # branch to "cmp2" routine 123 mov.w %cc,_tmp # save off condition codes 124 addq.l &0x8,%sp # clear arguments from stack 125 126Exception reporting: 127-------------------- 128If the instruction being emulated is a divide and the source 129operand is a zero, then the library routine, as its last 130instruction, executes an implemented divide using a zero 131source operand so that an "Integer Divide-by-Zero" exception 132will be taken. Although the exception stack frame will not 133point to the correct instruction, the user will at least be able 134to record that such an event occurred if desired. 135 13668060ILSP entry points: 137----------------------- 138_060ILSP_TOP: 1390x000: _060LSP__idivs64_ 1400x008: _060LSP__idivu64_ 141 1420x010: _060LSP__imuls64_ 1430x018: _060LSP__imulu64_ 144 1450x020: _060LSP__cmp2_Ab_ 1460x028: _060LSP__cmp2_Aw_ 1470x030: _060LSP__cmp2_Al_ 1480x038: _060LSP__cmp2_Db_ 1490x040: _060LSP__cmp2_Dw_ 1500x048: _060LSP__cmp2_Dl_