pizlonator

Here's a much more complete description of how I do SSA, beyond just how I do Phis.

This describes how I do SSA form, which avoids the need to have any coupling between CFG data structures and SSA data structures.

Let's first define a syntax for SSA and some terminology. Here's an example SSA node:

A = Add(B, C)

In reality, this will be a single object in your in-memory representation, and the names are really addresses of those objects. So, this node has an "implicit variable" called A; it's the variable that is implicitly assigned to when you execute the node. If you then do:

igorburago

// Copyright 2024 Igor Burago
// SPDX-License-Identifier: ISC

#include <math.h> // for partition_floyd_rivest()
#include <stddef.h> // ptrdiff_t
#include <stdint.h>
#include <string.h> // memcpy(), memmove(), memset()

// Built-in u128 is not strictly required, but it makes mcg64 simpler and faster.
typedef __uint128_t uint128_t;

mariusae

commit 989ecf2db1b2c5aaa21299e7c78108eb29935e11
Author: Marius Eriksen <[email protected]>
Date:   Tue Jan 4 12:29:12 2022 -0800

    acme: acmesrv

diff --git a/src/cmd/acme/acme.c b/src/cmd/acme/acme.c
index d001a2a8..2ebe5d3d 100644
--- a/src/cmd/acme/acme.c
+++ b/src/cmd/acme/acme.c

pervognsen

A traditional table-based DFA implementation looks like this:

uint8_t table[NUM_STATES][256]

uint8_t run(const uint8_t *start, const uint8_t *end, uint8_t state) {
    for (const uint8_t *s = start; s != end; s++)
        state = table[state][*s];
    return state;
}

ityonemo

A half-hour to learn Zig

This is inspired by https://fasterthanli.me/blog/2020/a-half-hour-to-learn-rust/

Basics

the command zig run my_code.zig will compile and immediately run your Zig program. Each of these cells contains a zig program that you can try to run (some of them contain compile-time errors that you can comment out to play with)

pervognsen

# Hash, displace, and compress: http://cmph.sourceforge.net/papers/esa09.pdf
# This is expected linear time for any seeded hash function that acts like a random hash function (universality isn't enough).
# (Actually, the code as written is O(n log n) when targeting 100% load. It's O(n) when targeting any smaller load factor.)
# You can make keys_per_bucket higher than the default of 4 but construction time will start to increase dramatically.
# The paper this is based on compresses the seeds (so the fact that the algorithm tries seeds in increasing order is important)
# which brings the representation size close to the information-theoretical minimum. I don't do any of that here, but it could
# be done as a postprocess.
def make_perfect_hash(keys, load_factor=1.0, keys_per_bucket=4, rhash=murmurhash, max_seed=1000000):
    m = int(len(keys) / load_factor)
    r = int(len(keys) / keys_per_bucket)

katef

#!/usr/bin/awk -f

function strrep(n, c) {
	s = ""

	for (i = 0; i < n; i++) {
		s = c s
	}

	return s

katef

#!/usr/bin/awk -f

# This program is a copy of guff, a plot device. https://github.com/silentbicycle/guff
# My copy here is written in awk instead of C, has no compelling benefit.
# Public domain. @thingskatedid

# Run as awk -v x=xyz ... or env variables for stuff?
# Assumptions: the data is evenly spaced along the x-axis

# TODO: moving average

mblondel

# Authors: Mathieu Blondel, Vlad Niculae
# License: BSD 3 clause

import numpy as np


def _gen_pairs(gen, max_iter, max_inner, random_state, verbose):
    rng = np.random.RandomState(random_state)

    # if tuple, interpret as randn

zbjornson

#include <cstddef>
#include <cmath>
#ifdef __FAST_MATH__
#error Compensated summation is unsafe with -ffast-math (/fp:fast)
#endif

inline static void kadd(double& sum, double& c, double y) {
  y -= c;
  auto t = sum + y;
  c = (t - sum) - y;