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* switch to new syntax for segment headers in C++Kartik Agaram2019-05-181-62/+62
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* 5163Kartik Agaram2019-05-151-1/+9
| | | | A few more places with flag corrections.
* 5162Kartik Agaram2019-05-151-7/+7
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* 5161Kartik Agaram2019-05-151-27/+27
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* 5160Kartik Agaram2019-05-151-10/+0
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* 5159Kartik Agaram2019-05-151-11/+68
| | | | One more instruction where I forgot to update the carry flag.
* start using the new carry flagKartik Agaram2019-05-131-3/+3
| | | | | Skimping on tests; the code changes seem pretty trivial. Will this fix CI?!
* flag tests for opcode 3dKartik Agaram2019-05-131-4/+47
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* .Kartik Agaram2019-05-131-5/+5
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* .Kartik Agaram2019-05-131-7/+7
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* flag tests for opcode 2dKartik Agaram2019-05-131-1/+46
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* flag tests for opcode 81Kartik Agaram2019-05-131-17/+135
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* flag tests for opcode 05Kartik Agaram2019-05-131-1/+50
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* .Kartik Agaram2019-05-131-7/+8
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* .Kartik Agaram2019-05-131-36/+36
| | | | | | Standardize layout of some code fragments, and fix several bugs in computing the overflow flag in the process. a64 = b32 + c32 doesn't benefit from `a` being 64-bit without casting `b`.
* .Kartik Agaram2019-05-131-2/+24
| | | | | Make the first instruction described something that doesn't touch flags, so we don't introduce too much complexity all at once.
* CF needs special handling for some arithmetic opsKartik Agaram2019-05-121-23/+107
| | | | Inline some macro definitions.
* snapshot of carry flag implementationKartik Agaram2019-05-121-19/+24
| | | | | | | | | | | | | | | | | | Tests failing. This approach seems wrong. I'm not sure even the tests are correct. Also, some open questions: 1. Should setting the overflow flag always set the carry flag? 2. Should the carry flag only be set on add/subtract/compare, or by all arithmetic ops? 3. Had to turn off the -ftrapv flag in `build`. Is there a way to detect overflow without actually causing overflow? Once we start setting CF correctly we have to implement jump above/below instructions (8- and 32-bit displacement variants). https://github.com/akkartik/mu/issues/30
* 5152 - check for stack underflow/overflow in VMKartik Agaram2019-05-111-2/+3
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* 5001 - drop the :(scenario) DSLKartik Agaram2019-03-121-337/+534
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I've been saying for a while[1][2][3] that adding extra abstractions makes things harder for newcomers, and adding new notations doubly so. And then I notice this DSL in my own backyard. Makes me feel like a hypocrite. [1] https://news.ycombinator.com/item?id=13565743#13570092 [2] https://lobste.rs/s/to8wpr/configuration_files_are_canary_warning [3] https://lobste.rs/s/mdmcdi/little_languages_by_jon_bentley_1986#c_3miuf2 The implementation of the DSL was also highly hacky: a) It was happening in the tangle/ tool, but was utterly unrelated to tangling layers. b) There were several persnickety constraints on the different kinds of lines and the specific order they were expected in. I kept finding bugs where the translator would silently do the wrong thing. Or the error messages sucked, and readers may be stuck looking at the generated code to figure out what happened. Fixing error messages would require a lot more code, which is one of my arguments against DSLs in the first place: they may be easy to implement, but they're hard to design to go with the grain of the underlying platform. They require lots of iteration. Is that effort worth prioritizing in this project? On the other hand, the DSL did make at least some readers' life easier, the ones who weren't immediately put off by having to learn a strange syntax. There were fewer quotes to parse, fewer backslash escapes. Anyway, since there are also people who dislike having to put up with strange syntaxes, we'll call that consideration a wash and tear this DSL out. --- This commit was sheer drudgery. Hopefully it won't need to be redone with a new DSL because I grow sick of backslashes.
* 4987 - support `browse_trace` tool in SubXKartik Agaram2019-02-251-28/+28
| | | | | | | | | | | | | | | | | | I've extracted it into a separate binary, independent of my Mu prototype. I also cleaned up my tracing layer to be a little nicer. Major improvements: - Realized that incremental tracing really ought to be the default. And to minimize printing traces to screen. - Finally figured out how to combine layers and call stack frames in a single dimension of depth. The answer: optimize for the experience of `browse_trace`. Instructions occupy a range of depths based on their call stack frame, and minor details of an instruction lie one level deeper in each case. Other than that, I spent some time adjusting levels everywhere to make `browse_trace` useful.
* 4886Kartik Agaram2018-12-281-2/+7
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* 4830Kartik Agaram2018-12-031-0/+151
| | | | | | New helper: printing a byte in textual (hex) form. This required adding instructions for bitwise shift operations.
* 4717Kartik Agaram2018-10-241-9/+9
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* 4695Kartik Agaram2018-10-141-25/+25
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* 4694Kartik Agaram2018-10-131-16/+16
| | | | Check for duplicate docstrings.
* 4693Kartik Agaram2018-10-131-16/+16
| | | | | | | | Add the standard mnemonic for each opcode. We aren't ever going to have complete docs of the subset of the x86 ISA we support, so we need to help readers cross-correlate with the complete docs.
* 4692 - update online help for subxKartik Agaram2018-10-131-13/+13
| | | | | | It now includes details for 8-bit registers. And we'll just use the classic names for the registers so that the relationships between 8- and 32-bit versions are more obvious.
* 4688Kartik Agaram2018-10-121-18/+18
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* 4687Kartik Agaram2018-10-121-8/+8
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* 4634Kartik Agaram2018-10-011-24/+24
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* 4547Kartik Agaram2018-09-161-1/+1
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* 4540Kartik Agaram2018-09-111-2/+2
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* 4538Kartik Agaram2018-09-071-9/+9
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* 4537Kartik Agaram2018-09-071-21/+40
| | | | | | | | | | | | | | | Streamline the factorial function; we don't need to save a stack variable into a register before operating on it. All instructions can take a stack variable directly. In the process we found two bugs: a) Opcode f7 was not implemented correctly. It was internally consistent but I'd never validated it against a natively running program. Turns out it encodes multiple instructions, not just 'not'. b) The way we look up imm32 operands was sometimes reading them before disp8/disp32 operands.
* 4469Kartik Agaram2018-08-031-0/+477