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lovely-error / tp.rs
Last active February 16, 2025 00:57
tagged ptr
use core::marker::PhantomData;
use core::mem::ManuallyDrop;
#[repr(C)] #[derive(Copy, Clone)]
union TaggedPtr64Repr<T> {
num: u64,
tag: ManuallyDrop<T>,
}
@lovely-error
lovely-error / no_rec_2_rec.lean
Created January 25, 2025 06:57
some random stuff
import Mathlib
example (p1: (V:Rat) = I * R)(vnz: Not (V = 0))(rnz: Not (R = 0)) : R = (I * R ^ 2) / V := by
let target := p1
let s1 : V = I * R <-> V / V = I * R / V := by
exact (iff_true_right (congrFun (congrArg HDiv.hDiv p1) V)).mpr p1
rw [s1] at target
let v_on_v_one: V / V = 1 := by
exact (div_eq_one_iff_eq vnz).mpr rfl
rw [v_on_v_one] at target
@lovely-error
lovely-error / deanoyify.rs
Created December 5, 2024 12:32
deanoyify rust
#![feature(decl_macro)]
macro d($ptr:expr) { unsafe { *$ptr } }
macro p($val:expr) { &raw mut $val }
macro pc($val:expr) { &raw const $val }
@lovely-error
lovely-error / mod-arith.lean
Created December 5, 2024 12:25
my arch-nemesis atm
import Batteries
def NModB251CC8 := Vector (Fin 251) 4
def MAX_VAL := (250 * 251^0) + (250 * 251^1) + (250 * (251 ^ 2)) + (250 * (251 ^ 3))
def NModSC := Fin (MAX_VAL + 1)
def from_NModB251CC8_to_Nat : NModB251CC8 -> Nat | i => (i.zipWithIndex.map (fun ⟨ a , i ⟩ => a * ((251:Nat) ^ i))).foldl Nat.add 0
example : from_NModB251CC8_to_Nat (Vector.mk #[250,250,250,250] (by decide)) < MAX_VAL + 1 := by trivial
@lovely-error
lovely-error / cond.c
Last active December 4, 2024 05:59
The only way to suppress speculation on branches??
#include <stdio.h>
#include <stdbool.h>
void lmao (bool cond) {
void* jmp_addr ;
__asm__ goto volatile (
"mov %[true_label], %[jmp_addr]\n\t"
"mov %[false_label], %%rbx\n\t"
"test %[cond], %[cond]\n\t"
"cmovz %%rbx, %[jmp_addr]\n\t"
@lovely-error
lovely-error / dyn.rs
Created October 29, 2024 14:07
(Almost) How to desugar dynsized values in rust
#![feature(ptr_metadata)]
// use libc; // 0.2.159
use std::alloc::Layout;
use std::ptr::copy_nonoverlapping;
use std::mem::forget;
use std::ptr::metadata;
use std::ptr::DynMetadata;
fn main() {
@lovely-error
lovely-error / quot.lean
Last active September 17, 2024 19:41
Injectivity of quotient constructor would lead to proof of false
def zmod : Nat -> Type | n => Quot (fun a b => a % n = b % n)
theorem prop_true_or_false : (p:Prop) -> p = False ∨ p = True := by
exact fun p => Or.symm (Classical.propComplete p)
theorem quot_ctor_inj : Quot.mk f a = Quot.mk f b -> a = b := by
intro k
-- injection k
admit
example {x:Rat} : 3 * x / 0.2 = (2 + 1/2) / (3 + 1/3) -> x = 1/20 := by
let is1 : (0.2:Rat) = 1/5 := by rfl
rw [is1]
let is2 : 3 * x / (1/5) = 3 * x * 5 := by
simp_all only [one_div, div_inv_eq_mul]
rw [is2]
let is3 : 3 * x * 5 = 15 * x := by
calc
3 * x * 5 = 3 * 5 * x := mul_right_comm 3 x 5
3 * 5 * _ = 15 * x := by
@lovely-error
lovely-error / vect_as_vv.agda
Last active May 29, 2024 00:25
Vect as W type
{-# OPTIONS --type-in-type #-}
open import Agda.Builtin.Nat
open import Agda.Builtin.Bool
data Prod (L R : Set) : Set where
pair : L -> R -> Prod L R
data Unit : Set where
pt : Unit