Re: [Freedos-kernel] Any interest in 486, 586, 686 kernels?
On Fri, May 3, 2013 at 4:02 AM, Eric Auer e.a...@jpberlin.de wrote: Hi Louis, if I understand your patch correctly, you only changed the build configuration to check how it affects the size of the compiled kernel before UPX compression, which also is an indicator of RAM size of the kernel? You changed the config.b, build.bat, buildall.bat files and generic.mak and watcom.mak and the resulting kernel sizes give the impression that in fact you only have FOUR distinct CPU optimizations, rather than seven cases... Yes. And just ran md5sum's against the kernels to verify this 3c0d2507d2595727b6d9a9a1bc979e72 kwc8616.sys 40d4679c99cd2579d0a96acdaaa62d99 kwc18616.sys 2234e5d367fb2562f430bc84dafd5c7d kwc28616.sys 623498bd71a46d16bcef211e743a9bed kwc38616.sys c3a607792ba8a0c8c8705dd370180619 kwc48616.sys c3a607792ba8a0c8c8705dd370180619 kwc58616.sys c3a607792ba8a0c8c8705dd370180619 kwc68616.sys 69eb7732f791db340632f722c9dbce16 kwc8632.sys f5c6d0d778fb196610385bc7c4689419 kwc18632.sys 1e4fd656603fd09171d9d85631e77045 kwc28632.sys b51d670433fd5d0d31d7babecbed84fe kwc38632.sys e1e87c09787ea3db18ccaa5c1675420a kwc48632.sys e1e87c09787ea3db18ccaa5c1675420a kwc58632.sys e1e87c09787ea3db18ccaa5c1675420a kwc68632.sys ...and I'll modify Eric's assertion. There's 5 kernel produced by OW for the 7 arch's. x86, 186, 286, 386, 486+. It would seem that OW doesn't know much about 586+ arch's but can use the instructions in special situations. And this makes sense when you consider when Watcom fell out of favor commercially and probably saw it's last real optimizer work. Kernels without FAT32: 086: 64158 bytes 186: 63028 bytes (286 same) 386: 62164 bytes 486: 62068 bytes (586 and 686 same) Kernels with FAT32: 086: 68358 bytes 186: 67180 bytes (286 same) 386: 66044 bytes 486: 65948 bytes (586 and 686 same) [SNIP] Big wins could be had on 586 with FPU memcpy 64-bit versus the 16-bit asm in the kernel now and possibly the string functions. But just an idea right now. -L -- Get 100% visibility into Java/.NET code with AppDynamics Lite It's a free troubleshooting tool designed for production Get down to code-level detail for bottlenecks, with 2% overhead. Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap2___ Freedos-kernel mailing list Freedos-kernel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-kernel
Re: [Freedos-kernel] Any interest in 486, 586, 686 kernels?
What's the difference between wcc wcc386? I noticed that wcc386 adds -5s, -5r, -fp5 (-6 equivalents) for stack, register and fpu optimization. Does wcc386 generate code that could be used in the kernel? -L On Fri, May 3, 2013 at 5:57 AM, Louis Santillan lpsan...@gmail.com wrote: On Fri, May 3, 2013 at 4:02 AM, Eric Auer e.a...@jpberlin.de wrote: Hi Louis, if I understand your patch correctly, you only changed the build configuration to check how it affects the size of the compiled kernel before UPX compression, which also is an indicator of RAM size of the kernel? You changed the config.b, build.bat, buildall.bat files and generic.mak and watcom.mak and the resulting kernel sizes give the impression that in fact you only have FOUR distinct CPU optimizations, rather than seven cases... Yes. And just ran md5sum's against the kernels to verify this 3c0d2507d2595727b6d9a9a1bc979e72 kwc8616.sys 40d4679c99cd2579d0a96acdaaa62d99 kwc18616.sys 2234e5d367fb2562f430bc84dafd5c7d kwc28616.sys 623498bd71a46d16bcef211e743a9bed kwc38616.sys c3a607792ba8a0c8c8705dd370180619 kwc48616.sys c3a607792ba8a0c8c8705dd370180619 kwc58616.sys c3a607792ba8a0c8c8705dd370180619 kwc68616.sys 69eb7732f791db340632f722c9dbce16 kwc8632.sys f5c6d0d778fb196610385bc7c4689419 kwc18632.sys 1e4fd656603fd09171d9d85631e77045 kwc28632.sys b51d670433fd5d0d31d7babecbed84fe kwc38632.sys e1e87c09787ea3db18ccaa5c1675420a kwc48632.sys e1e87c09787ea3db18ccaa5c1675420a kwc58632.sys e1e87c09787ea3db18ccaa5c1675420a kwc68632.sys ...and I'll modify Eric's assertion. There's 5 kernel produced by OW for the 7 arch's. x86, 186, 286, 386, 486+. It would seem that OW doesn't know much about 586+ arch's but can use the instructions in special situations. And this makes sense when you consider when Watcom fell out of favor commercially and probably saw it's last real optimizer work. Kernels without FAT32: 086: 64158 bytes 186: 63028 bytes (286 same) 386: 62164 bytes 486: 62068 bytes (586 and 686 same) Kernels with FAT32: 086: 68358 bytes 186: 67180 bytes (286 same) 386: 66044 bytes 486: 65948 bytes (586 and 686 same) [SNIP] Big wins could be had on 586 with FPU memcpy 64-bit versus the 16-bit asm in the kernel now and possibly the string functions. But just an idea right now. -L -- Get 100% visibility into Java/.NET code with AppDynamics Lite It's a free troubleshooting tool designed for production Get down to code-level detail for bottlenecks, with 2% overhead. Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap2___ Freedos-kernel mailing list Freedos-kernel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-kernel
Re: [Freedos-kernel] Any interest in 486, 586, 686 kernels?
Kernels with FAT32: 086: 68358 bytes 186: 67180 bytes (286 same) 386: 66044 bytes 486: 65948 bytes (586 and 686 same) It is interesting that even 186 instructions do make a quite big difference and that there is a difference at all between 386 and 486. With 186, you get pusha and popa, shift/rotate by fixed numbers of bits. ENTER LEAVE In the past, we compiled kernels for 8086, 186 and 386 separately afair. I guess we got lazy and have dropped 186 because very few users have 186/286 as their CPU? They either have modern or REALLY old. this is not about 'lazy' it's easier for the user to select between 2 choices then between 4. multiply by 2 (FAT16/FAT32), this is 4 or 8 kernels. there's not much use for a 186 kernel as NOBODY has 186/286 machines these days, Also, we keep offering 8086 compiles for the sake of good old times and for people with emulators. The 386 optimization is useful and we already used it: Having 32 bit computations helps even for DOS. There are also some new bit string opcodes, SETCC (conditional set a byte) nothing of this is used by the compiler JCXZ was always supported and near conditional jumps and loops that are supported starting at 386. *far* conditional jumps started with 386. however what *IS* used by wcc is the additional FS and GS register some (few) push DWORD constant what would be useful, but is not used by WCC dword arithmetic filesystem code uses long variables everywhere Your 486 to 686 kernels are the same size and 486s only XADD and BSWAP (and CMPXCHG). It is impressive that those actually make any (100 byte) difference! strange enough, compiling here with -3 and -6 makes exactly no difference. using watcom 1.9 could you post the compiled files, or even for %i in (*.obj) do wdis -l -a -s %i for -3 and -6 and show us the differences ? Maybe your compiles assume that 486 does and 386 does not have FPU? That would not be very accurate. pointless as the kernel doesn't use any FPU code As with 286, the news in 586 is mostly protected mode related (simply speaking). Neither CMPXCHG8B nor the time stamp counter nor CPUID bothers DOS. The main news in 686 would be CMOV, a conditional MOV, but looking only at kernel sizes, it is likely that the compiler just does not use CMOV for 686. It is odd to get exactly the same size otherwise. it doesn't use cmov For even newer CPU, you could use FPU and vector (MMX, SSE, SSE2, SSE3, SSE4a, EMMX, 3dNow, 3dNow+, SSE4.1, SSE4.2, AVX FMA, not AES ;-)) instructions but it is highly unlikely that those make any DOS difference. At most they could speed up memmove. as the kernel doesn't much memcpy/memmove, you can't accelerate it by any significant amount.otherwise we *would* have rep movsD tom -- Get 100% visibility into Java/.NET code with AppDynamics Lite It's a free troubleshooting tool designed for production Get down to code-level detail for bottlenecks, with 2% overhead. Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap2 ___ Freedos-kernel mailing list Freedos-kernel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-kernel
Re: [Freedos-kernel] Any interest in 486, 586, 686 kernels?
What's the difference between wcc wcc386? code generation for 16 bit (DOS) or 32 bit (windows) Does wcc386 generate code that could be used in the kernel? no Big wins could be had on 586 with FPU memcpy 64-bit versus the 16-bit asm in the kernel now and possibly the string functions. But just an idea right now. the kernel doesn't copy (much). nothing to be gained. tom -- Get 100% visibility into Java/.NET code with AppDynamics Lite It's a free troubleshooting tool designed for production Get down to code-level detail for bottlenecks, with 2% overhead. Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap2 ___ Freedos-kernel mailing list Freedos-kernel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-kernel
