Hacker News: cataphract

New comment by cataphract in "Everything in C is undefined behavior"

cataphract — Wed, 20 May 2026 10:24:05 +0000

Not really. Wait until the compiler starts vectorizing your code and using instructions requiring alignment (like the ones with A or NT in the mnemonic).

New comment by cataphract in "US Supreme Court reviews police use of cell location data"

cataphract — Tue, 28 Apr 2026 18:00:41 +0000

I didn't justify anything. Just pointed out the false equivalence. We could also argue about the effect of systemic shoplifting, but that is also neither here nor there.

New comment by cataphract in "US Supreme Court reviews police use of cell location data"

cataphract — Tue, 28 Apr 2026 00:21:59 +0000

I have no doubt this geo fencing data solves crimes and I don't even think it's as bad as e.g. the long surveillance in Carpenter.

The problem is that the police are going to start using like they do with much more precise DNA data, and more innocent people are going to caught in the net.

The bar to convict someone (or, more likely, to convince an innocent person to take a plea deal) is not as high ("beyond a reasonable doubt") as some people think. Get caught apparently contradicting hard data or even a witness and there goes your reasonable doubt.

New comment by cataphract in "US Supreme Court reviews police use of cell location data"

cataphract — Tue, 28 Apr 2026 00:02:18 +0000

Come on. Not that I support destroying anything, private or public, for rhetorical effect. But assaulting someone or destroying their property has an incomparably larger impact on that individual than destroying a vehicle that won't even show up in Google's balance sheet.

New comment by cataphract in "US Supreme Court reviews police use of cell location data"

cataphract — Mon, 27 Apr 2026 23:49:53 +0000

They killed a lot of functionality. For instance, if you opened the details of a place, it used to tell you when all your visits were. I feel the timeline is mostly abandonware these days.

New comment by cataphract in "China blocks Meta's acquisition of AI startup Manus"

cataphract — Mon, 27 Apr 2026 23:24:24 +0000

The US is a democracy, and people are given many procedural and substantive rights, even Guantanamo detainees (we can argue if Boumediene had any practical effect, but we wouldn't have seen the same from China).

But Americans are under the impression that what the world sees is what they mostly see -- the domestic side. And to a certain extent, they do thanks to its cultural influence. This democracy/rule of law, however, is completely absent in way it behaves outside its borders and it's now clearer than ever to everyone that the US is the biggest source of instability in the world. More than Russia. Certainly more than China.

New comment by cataphract in "In the UK, EVs are cheaper than petrol cars, thanks to Chinese competition"

cataphract — Wed, 22 Apr 2026 01:14:17 +0000

Then the US should have done like the EU and apply anti-subsidy countermeasures -- and show before impartial WTO arbitrators the adequacy of the mesures.

But of course the US (or Canada) can't justify their 100% duty in those terms, so they don't even try.

New comment by cataphract in "All phones sold in the EU to have replaceable batteries from 2027"

cataphract — Tue, 21 Apr 2026 00:26:36 +0000

Do you think fuel efficiency or emission standards "slowed down innovation"? They brought a huge amount of innovation: lighter materials, better aerodynamics, higher compression ratios, direct injection, better mixture control, etc.

There will still be innovation; the solutions will just have satisfy the new parameters.

New comment by cataphract in "All phones sold in the EU to have replaceable batteries from 2027"

cataphract — Tue, 21 Apr 2026 00:04:18 +0000

I don't think the objective is to make it a "superior product" in the somewhat circular way you're defining it (i.e., the market equilibrium that we settled on). It's one of several measures to try to have people keep their phones for longer and cut e-waste.

New comment by cataphract in "College instructor turns to typewriters to curb AI-written work"

cataphract — Sun, 19 Apr 2026 11:48:57 +0000

I think the only defense of the new model is that it forces students to learn throughout the semester, rather than just before the exam. Which is easier and more effectively engages long term memory (like doing more rounds of spaced repetition).

I definitely could tell the difference, though most of the time I just studied full 4-7 days before the exam.

New comment by cataphract in "ESP32-S31: Dual-Core RISC-V SoC with Wi-Fi 6, Bluetooth 5.4, and Advanced HMI"

cataphract — Fri, 03 Apr 2026 11:53:27 +0000

The C6 and the H2 already support ZigBee. Their SDK has a thin layer on top of zboss.

New comment by cataphract in "Everything old is new again: memory optimization"

cataphract — Sat, 28 Mar 2026 18:00:03 +0000

I'm not sure if you're just trolling, but I'll give the same example I gave before (you can get even wilder simplifications -- called relaxations -- with TLS, since there are 4 levels of generality there). I'm not sure what you meant by "changing isntructions", but in the first case the linker did the fixup indicated by the relocation and in the second reduced the generality of the reference (one less level of indirection by changing mov to lea) because it knew the symbol could not be preempted (more exactly, the R_X86_64_REX_GOTPCRELX relocation allows the linker to do the relaxation if it can determine that it's safe to)

  root@1f0775a74fd7:/tmp# cat a.c
  int glob;
  int main() {
   return glob;
  }
  root@1f0775a74fd7:/tmp# gcc -c a.c -fPIC -o a.o
  root@1f0775a74fd7:/tmp# objdump --disassemble=main a.o
  
  a.o:     file format elf64-x86-64
  
  
  Disassembly of section .text:
  
  0000000000000000 :
     0: f3 0f 1e fa           endbr64
     4: 55                    push   %rbp
     5: 48 89 e5              mov    %rsp,%rbp
     8: 48 8b 05 00 00 00 00  mov    0x0(%rip),%rax        # f 
     f: 8b 00                 mov    (%rax),%eax
    11: 5d                    pop    %rbp
    12: c3                    ret
  root@1f0775a74fd7:/tmp# readelf -rW a.o | grep glob
  000000000000000b  000000030000002a R_X86_64_REX_GOTPCRELX 0000000000000000 glob - 4
  root@1f0775a74fd7:/tmp# gcc -shared -o a.so a.o
  root@1f0775a74fd7:/tmp# objdump --disassemble=main a.so
  (...)
  00000000000010f9 :
      10f9: f3 0f 1e fa           endbr64
      10fd: 55                    push   %rbp
      10fe: 48 89 e5              mov    %rsp,%rbp
      1101: 48 8b 05 b8 2e 00 00  mov    0x2eb8(%rip),%rax        # 3fc0 
      1108: 8b 00                 mov    (%rax),%eax
      110a: 5d                    pop    %rbp
      110b: c3                    ret
  (...)
  root@1f0775a74fd7:/tmp# readelf -r a.so | grep glob
  000000003fc0  000600000006 R_X86_64_GLOB_DAT 000000000000400c glob + 0
  root@1f0775a74fd7:/tmp# gcc -shared -Wl,-Bsymbolic -o a.symb.so a.o
  root@1f0775a74fd7:/tmp# readelf -r a.symb.so | grep glob
  root@1f0775a74fd7:/tmp# objdump --disassemble=main a.symb.so
  (...)
  Disassembly of section .text:
  
  00000000000010f9 :
      10f9: f3 0f 1e fa           endbr64
      10fd: 55                    push   %rbp
      10fe: 48 89 e5              mov    %rsp,%rbp
      1101: 48 8d 05 04 2f 00 00  lea    0x2f04(%rip),%rax        # 400c 
      1108: 8b 00                 mov    (%rax),%eax
      110a: 5d                    pop    %rbp
      110b: c3                    ret
  (...)

New comment by cataphract in "Everything old is new again: memory optimization"

cataphract — Sat, 28 Mar 2026 01:32:42 +0000

Assuming the symbol is defined in the library, when the static linker runs (ld -- we're not talking ld.so), it will decide whether the global variable is preemptable or not, that is, if it can be resolved to a symbol outside the dso. Generally, by default it is, though this depends on many things -- visibility attributes, linker scripts, -Bsymbolic, etc. If it is, ld will have the final code reach into the GOT. If not, it can just use instruction (PC) relative offsets.

New comment by cataphract in "Everything old is new again: memory optimization"

cataphract — Fri, 27 Mar 2026 20:48:01 +0000

ld writes to the GOT. The executable segment where .text lives is not written to (it's position independent code in dynamic libraries).

ASLR is not an obstacle -- the same exact code can be mapped into different base addresses in different processes, so they can be backed by the same actual memory.

New comment by cataphract in "Malus – Clean Room as a Service"

cataphract — Fri, 13 Mar 2026 09:42:31 +0000

What's been driving up the cost of construction (it's already up to 2000-2400 eur/m2 for a detached house in Portugal) has been mostly cost of materials and labour.

People complain about the regulations, but they also complain about houses that are structurally unsound, unventilated, flammable, badly isolated acoustically and thermally and so on... I don't think going back is the way to go. It's true that sometimes licensing that too long, though.

New comment by cataphract in "Traffic from Russia to Cloudflare is 60% down from last year"

cataphract — Tue, 10 Mar 2026 14:53:32 +0000

You can celebrate the outcome even if you disagree with the means or the motivations.

New comment by cataphract in "Global warming has accelerated significantly"

cataphract — Fri, 06 Mar 2026 18:12:20 +0000

Yeah, never heard of such a thing. The restrictions are placing the units in common areas of the buildings -- in that case you need permission -- and external walls are usually common parts. Placing them in the façade may have additional restrictions.

But, if anything, energy efficiency standards for new construction are so strict that heat is becoming less of a problem.

New comment by cataphract in "Global warming has accelerated significantly"

cataphract — Fri, 06 Mar 2026 18:06:22 +0000

> Why would a country like India pay/sacrifice to reduce emissions while western citizens still pollute at much higher levels after reaping all the spoils from historical pollution?

To avoid their country having large regions become uninhabitable?

New comment by cataphract in "The happiest I've ever been"

cataphract — Sat, 28 Feb 2026 20:51:03 +0000

I think there's a middle ground. I like coming up with solutions to problems (mostly technical problems, may even be very low level ones). But I always found writing the code generally tedious. Basically, once I had a good detailed idea of what the implementation would look like, actually executing the plan would bore me.

AI is still not competent enough to come up with good solutions in many things I work on. So, at least so far, AI has made me happier.

New comment by cataphract in "I am directing the Department of War to designate Anthropic a supply-chain risk"

cataphract — Fri, 27 Feb 2026 23:57:21 +0000

Unconstitutionally, no less:

"No Tax or Duty shall be laid on Articles exported from any State.".