Post by thread:Re[2]: C Compiler

Well on the same code from before, here is the result of the MPLABC Demo version! It uses 14 words of ROM. regards, Scott. ===================================================================== void main() { /* Variables local to main */ 0026 char a; 0027 short int b; 0005 3001 MOVLW 01h if ( a == 1 || a == 2) 0006 1283 BCF 03,5 0007 0226 SUBWF 26,W 0008 1903 BTFSC 03,2 0009 280F GOTO 000Fh 000A 3002 MOVLW 02h 000B 1283 BCF 03,5 000C 0226 SUBWF 26,W 000D 1D03 BTFSS 03,2 000E 2812 GOTO 0012h 000F 1283 BCF 03,5 b = 0; 0010 01A7 CLRF 27 0011 2815 GOTO 0015h else b = 1; 0012 3001 MOVLW 01h 0013 1283 BCF 03,5 0014 00A7 MOVWF 27 0015 0008 RETURN }

> I guess, if you plan to hack with it, it may be fun enjoy it. But if you > really plan to do something serious and you don't like asm you should get > a bug free C compiler. MChips mplabc sounds worse than ccs. It may be > better idea to develop C based program for a different micro. I wouldn't know if this statement about CCS is true, but to say that it's better to use another controller for C-based programs is totally wrong. There are C-compilers available for PICmicros that are "bug-free". -Dag

>> I guess, if you plan to hack with it, it may be fun enjoy it. But if you >> really plan to do something serious and you don't like asm you should get >> a bug free C compiler. MChips mplabc sounds worse than ccs... > I believe both the mentioned bugs were corrected. CCS always responds in a > timely manner to bug reports. No matter which compiler you use you > absolutely must look at the assembly output to see what the compiler has > wrought, and you must understand what the compiler is going to do with your > code. With a good C-compiler, you will not have to look at the asm output (of course), and that good compilers exists. -Dag

Bob Lunn 08/06/97 06:12 PM > There are C-compilers available for PICmicros that are "bug-free". Hmm, even allowing for the quote marks this is a dangerous assertion. Proving the correctness of anything as complicated as a compiler is a daunting undertaking. If any supplier of a Pic 'C' compiler is prepared to prove its correctness, I would be very interested in hearing it. ___Bob

---Original Message----- From: spam_OUTblunnTakeThisOuTKEYCORP.COM.AU <.....blunnKILLspam@spam@KEYCORP.COM.AU> To: PICLISTKILLspamMITVMA.MIT.EDU <.....PICLISTKILLspam.....MITVMA.MIT.EDU> Date: Wednesday, 6 August 1997 17:45 Subject: Re: Re[2]: C compiler {Quote hidden}>Bob Lunn >08/06/97 06:12 PM > > >> There are C-compilers available for PICmicros that are "bug-free". > > Hmm, even allowing for the quote marks this is a dangerous assertion. > > Proving the correctness of anything as complicated as a compiler is > a daunting undertaking. If any supplier of a Pic 'C' compiler is >prepared > to prove its correctness, I would be very interested in hearing it. That statement raised my eyebrows, too. Two additions. 1 - you don't need to qualify it with Pic C compiler. Any C compiler would be included in your statement. 2 - you can't prove such a thing. Disprove it, yes. Even validation suites can only disprove. MikeS <EraseMEmikesmith_ozspam_OUTTakeThisOuTrelaymail.net>

We just completed our first project with the HiTech compiler for the PIC16C73A. The HiTech compiler had 0 install problems and 0 compilation/user problems. It worked extremely well. There was no need to ask for emergency "bug fixes". "Bug free"is a little exaggerated of a statement. Perhaps the same comments could be said of assemblers, and maybe of all software that does anything significant? Maybe we should lay-out PCBs by hand because the CAD software has bugs? (Note: I do not say "might"have bugs). We have extensively used the Bytecraft C compiler through version 2.07bbs and have also used the new HiTech C compiler v7.70 PL1 CDROM release. The MicroChip MPLAB-C was based on an older version of the Bytecraft compiler that is known to have MANY bugs. Shame on Microchip for distributing it! James ---------- {Quote hidden}> From: blunnspam_OUTKEYCORP.COM.AU > To: @spam@PICLISTKILLspamMITVMA.MIT.EDU > Subject: Re: Re[2]: C compiler > Date: Wednesday, August 06, 1997 11:12 AM > > Bob Lunn > 08/06/97 06:12 PM > > > > There are C-compilers available for PICmicros that are "bug-free". > > Hmm, even allowing for the quote marks this is a dangerous assertion. > > Proving the correctness of anything as complicated as a compiler is > a daunting undertaking. If any supplier of a Pic 'C' compiler is > prepared > to prove its correctness, I would be very interested in hearing it. > > ___Bob

> I wouldn't know if this statement is true, but to say that it's > better to use another controller for C-based programs is totally wrong. > There are C-compilers available for PICmicros that are "bug-free". I have been following this thread with considerable interest. The compiler developers are faced with several major issues related to bugs, features and optimization. When we are aggressive with our optimization then the likelihood of bugs increases. The same is true with features. Bugs are induced in the compilers when we change implementation strategies on new processors or processors where there is not a large body of big completed applications to understand the subtle issues. The early MPC development saw a lot of this until experience with the PIC processor families stabilized the compiler. Interestedly the current support for the 16C66, '67, '76, '77 required the knowledge gained from the first half dozen or so applications now going into production. Testing, as several have pointed out, determines only what doesn't work. It is a very tough problem. The tests we use come from four sources. We buy commercial test suites, two separate groups in Byte Craft write test suites (developers and customer support people), We contract out the writing of specific test suites to outside companies specializing in this type of work and we use the publicly available test suites and example code. Our tests come from

Hi James, >> see http://people.frankfurt.netsurf.de/wky/pic.htm#table4 JC> But none of those C compilers were freeware or shareware, they all had a JC> license fee. Was there any particular compiler you were referring to, JC> Wolfgang? http://personal.eunet.fi/pp/jokinen/ www.geocities.com/SiliconValley/Network/3656/c.html are free. HiTech has a version free for 21 days. BTW, why do you think somebody should give away a C compiler for free? "Shareware" meens 'try before buy' - nothing else. Regards, Wolfgang -- PIC links: http://people.frankfurt.netsurf.de/wky/pic.htm