31–40 of 238 posts
Earlier quoted context omitted.
That would be cool, but I would not want to hand-code assembly on such a platform. That makes memory segmentation look fun.
The table could be created from your assembly automatically? I would never want to code the hex directly in any case.
I thought it couldn't a second ago. I don't know why. Makes no sense to me now.
x86 is the worst ISA. If you want to play with assembler without feeling a desire to stab yourself and end it all, I recommend ARM. Or go learn Z80, x86's weird, 8-bit cousin (it had a 16-bit version, but it sold poorly), which had a greater emphasis on backwards compatability (you can run code from the original 8080 on a Z80, unchanged), and is nicer to work with (because it wasn't extended in unticipated directions…
The Z80 only has a 16-bit address space.
My favorite CISC architecture is the 68000 series.
x86 is the worst ISA. If you want to play with assembler without feeling a desire to stab yourself and end it all, I recommend ARM. Or go learn Z80, x86's weird, 8-bit cousin (it had a 16-bit version, but it sold poorly), which had a greater emphasis on backwards compatability (you can run code from the original 8080 on a Z80, unchanged), and is nicer to work with (because it wasn't extended in unticipated directions…
> x86 is the worst ISA. x86 is clearly not a beautiful ISA, but it is not as black as it is painted. The first thing that one should understand is large parts of the encoding of the instructions make a lot more sense once one writes them down in octal instead of hexadecimal (something even the Intel people who wrote the reference manual seem to have missed): > http://www.dabo.de/ccc99/www.camp.ccc.de/radio/help.txt
x86 is the worst ISA. If you want to play with assembler without feeling a desire to stab yourself and end it all, I recommend ARM. Or go learn Z80, x86's weird, 8-bit cousin (it had a 16-bit version, but it sold poorly), which had a greater emphasis on backwards compatability (you can run code from the original 8080 on a Z80, unchanged), and is nicer to work with (because it wasn't extended in unticipated directions…
I never felt more like stabbing myself than when trying to cipher out exactly which immediate values are possible on ARM, and which are not. X86 I happen to enjoy. It is not "the worst ISA" by any means. It has wonderful code density, which turns out the be very important. There's a reason that x86 won and continues to win.
It depends if you're compiling for ARM or Thumb. The main rules are:
ARM and 32-bit Thumb instructions: 12 bits for arithmetic data processing instructions and load/store, 8bits with even rotate right for bitwise data processing instructions + MOV and MVN
16-bit Thumb: 3 bits for arithmetic instructions with Rd != Rn, 5 bits for shifts (so the whole range is covered) and load / store (but shifted left by the size of the data, i.e. the maximum offset for this version of LDR is (0x1F I doubt x86's popularity has much to do with its instruction set at this point. In particular, the variable length instructions are a pain for decoders (both hardware and software).
x86 is the worst ISA. If you want to play with assembler without feeling a desire to stab yourself and end it all, I recommend ARM. Or go learn Z80, x86's weird, 8-bit cousin (it had a 16-bit version, but it sold poorly), which had a greater emphasis on backwards compatability (you can run code from the original 8080 on a Z80, unchanged), and is nicer to work with (because it wasn't extended in unticipated directions…
>It also didn't have memory segmentation The Z80 only has a 16-bit address space. My favorite CISC architecture is the 68000 series.
The 68k (and it's 8-bit semi-cousin, the 6809) were very nice. However, unlike the Z80, the 6502, and x86, they're no longer being made, and are increasingly rare.
x86 is the worst ISA. If you want to play with assembler without feeling a desire to stab yourself and end it all, I recommend ARM. Or go learn Z80, x86's weird, 8-bit cousin (it had a 16-bit version, but it sold poorly), which had a greater emphasis on backwards compatability (you can run code from the original 8080 on a Z80, unchanged), and is nicer to work with (because it wasn't extended in unticipated directions…
But definitely Z80 over x86. x86 is pain.
Earlier quoted context omitted.
I never felt more like stabbing myself than when trying to cipher out exactly which immediate values are possible on ARM, and which are not. X86 I happen to enjoy. It is not "the worst ISA" by any means. It has wonderful code density, which turns out the be very important. There's a reason that x86 won and continues to win.
Well, yes. That part sucks. But on x86, everything is like that. I'd rather have one weird, inconsistant thing than an amorphous, ever-shifting mass of them. Which is x86 in a nutshell. Here's a handy heuristic: if somebody claims to know every x86-64 instruction (or even every x86-32 instruction), you can be at least 90% sure they're lying.
I very much prefer ARM myself, but you can probably apply the same rule of thumb to it. There are upwards of 400 instructions both in AArch32 and AArch64, with a fair number of differences between the two.
Edit: I've also posted a breakdown of the immediate limitations for ARM in this thread. It's not that complicated when sticking to the standard instructions.
x86 is the worst ISA. If you want to play with assembler without feeling a desire to stab yourself and end it all, I recommend ARM. Or go learn Z80, x86's weird, 8-bit cousin (it had a 16-bit version, but it sold poorly), which had a greater emphasis on backwards compatability (you can run code from the original 8080 on a Z80, unchanged), and is nicer to work with (because it wasn't extended in unticipated directions…
I'd recommend learning 68k instead. Or MIPS. But definitely Z80 over x86. x86 is pain.
MIPS and ARM are fun, though, AFAICT. As is 6502.
x86 is the worst ISA. If you want to play with assembler without feeling a desire to stab yourself and end it all, I recommend ARM. Or go learn Z80, x86's weird, 8-bit cousin (it had a 16-bit version, but it sold poorly), which had a greater emphasis on backwards compatability (you can run code from the original 8080 on a Z80, unchanged), and is nicer to work with (because it wasn't extended in unticipated directions…
Another good one for learning is the 6502. Don't forget to buy a copy of Lance A. Leventhal's "6502 Assembly Language Programming". Great book for learning not only assembly, but also the fundamentals leading up to assembly.
I learned to program on the 6502 based VIC-20 using Lance Leventhal's "6502 Assembly Language Subroutines" as a guide by manually assembling and poking into memory. What a fun time.
Earlier quoted context omitted.
> x86 is the worst ISA. x86 is clearly not a beautiful ISA, but it is not as black as it is painted. The first thing that one should understand is large parts of the encoding of the instructions make a lot more sense once one writes them down in octal instead of hexadecimal (something even the Intel people who wrote the reference manual seem to have missed): > http://www.dabo.de/ccc99/www.camp.ccc.de/radio/help.txt
...that really doesn't help with the issues I have: the instruction set is an absolutely ugly jumble of almost 40 years of religious backwards compatability, odd hacks, and various extensions.
Like POSIX, MS-Windows, X11, WinAPI, C++, HTML5, ... ;-)