I can see bytecode, but i need to see values... Le lundi 4 mars 2019 17:21:38 UTC+1, Leszek Swirski a écrit : > > That's a surprisingly tricky thing to do, despite sounding simple. You > could add a new runtime function (e.g. LogComparison) which you call at the > beginning of CodeStubAssembler::Equal, passing it the LHS and RHS. A bigger > cannon that you could use on this mosquito is to enable ignition tracing > (v8_enable_trace_ignition = true in gn args) and run your code with > `--no-opt --trace-ignition`, which will print a line for every bytecode > executed that you can then grep through. > > On Mon, Mar 4, 2019 at 4:52 PM <exam...@gmail.com <javascript:>> wrote: > >> Thanks >> >> in fact what i want to do is to log all comparisons at excecution. What >> is the best way to do that ? >> >> Le lundi 4 mars 2019 13:15:53 UTC+1, Leszek Swirski a écrit : >>> >>> --force-slow-path is a bit confusing, and maybe not well named, I >>> believe it only affects some builtins (regex etc.) >>> >>> For some more detail, a lot of functionality in V8 is implemented >>> multiple times -- common, simpler fast paths (e.g. comparing numbers as you >>> are) are implemented in "assembly" (which used to be actual machine code, >>> now it's mostly CSA <https://v8.dev/docs/csa-builtins> or Torque >>> <https://v8.dev/docs/torque-builtins> code), less common "slow" paths >>> (e.g. comparing BigInts) will go to the "runtime" (i.e. into the C++ code). >>> These runtime functions also have fast and slow paths (which are really >>> more like medium speed and extra slow), and the flag you mentioned is for >>> forcing those slow paths. >>> >>> For specifically comparison, you probably want to hook into >>> CodeStubAssembler::Equal >>> <https://cs.chromium.org/chromium/src/v8/src/code-stub-assembler.cc?type=cs&q=CodeStubAssembler::Equal&sq=package:chromium&g=0&l=11680>, >>> >>> though keep in mind that the linked code is *generating* the comparison >>> code, not *calculating* or executing it. You'll also want to disable >>> optimisation (--no-opt) to make sure you don't enter optimized code (which >>> inlines the comparison). >>> >>> - Leszek >>> >>> On Mon, Mar 4, 2019 at 9:49 AM <exam...@gmail.com> wrote: >>> >>>> I have tried to add --force-slow-path argument and it does not change >>>> anything >>>> >>>> Le lundi 4 mars 2019 08:56:09 UTC+1, exam...@gmail.com a écrit : >>>>> >>>>> Thanks >>>>> >>>>> What do you mean by 'slow path' ? >>>>> Where should i put some code in order to hook comparisons operators ? >>>>> >>>> -- >>>> -- >>>> v8-dev mailing list >>>> v8-...@googlegroups.com >>>> http://groups.google.com/group/v8-dev >>>> --- >>>> You received this message because you are subscribed to the Google >>>> Groups "v8-dev" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to v8-dev+un...@googlegroups.com. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> -- >> -- >> v8-dev mailing list >> v8-...@googlegroups.com <javascript:> >> http://groups.google.com/group/v8-dev >> --- >> You received this message because you are subscribed to the Google Groups >> "v8-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to v8-dev+un...@googlegroups.com <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> >
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