2f:T74a,md`## WASM version (made in the [AssemblyScript Editor](https://www.assemblyscript.org/editor.html#IyFvcHRpbWl6ZT1zcGVlZCZydW50aW1lPW5vbmUmbm9FeHBvcnRNZW1vcnkKY29uc3QgZXBzOiBmNjQgPSAyLjMyODMwNjQzNjUzODY5NjNlLTEwOwpjb25zdCBtOiB1NjQgPSA2MzY0MTM2MjIzODQ2NzkzMDA1Owpjb25zdCBpbmM6IHU2NCA9IDE0NDI2OTUwNDA4ODg5NjM0MDc7CgpsZXQgc3RhdGU6IHU2NCA9IDE7CgpleHBvcnQgZnVuY3Rpb24gcmFuZG9tKCk6IGY2NCB7CiAgbGV0IG9sZHN0YXRlID0gc3RhdGUgKiA2MzY0MTM2MjIzODQ2NzkzMDA1ICsgMTQ0MjY5NTA0MDg4ODk2MzQwNzsKICBzdGF0ZSA9IG9sZHN0YXRlOwogIGNvbnN0IHhvcnNoaWZ0ZWQgPSB1MzIoKChvbGRzdGF0ZSA+Pj4gMTgpIF4gb2xkc3RhdGUpID4+IDI3KTsKICBjb25zdCBvdXRfaW50ID0gcm90cih4b3JzaGlmdGVkLCB1MzIob2xkc3RhdGUgPj4gNTkpKTsKICByZXR1cm4gZXBzICogb3V0X2ludDsKfQojIWh0bWwKPHRleHRhcmVhIGlkPSJvdXRwdXQiIHN0eWxlPSJoZWlnaHQ6IDEwMCU7IHdpZHRoOiAxMDAlIiByZWFkb25seT48L3RleHRhcmVhPgo8c2NyaXB0Pgpsb2FkZXIuaW5zdGFudGlhdGUobW9kdWxlX3dhc20sIHsgLyogaW1wb3J0cyAqLyB9KQogIC50aGVuKCh7IGV4cG9ydHMgfSkgPT4gewogICAgY29uc3Qgb3V0cHV0ID0gZG9jdW1lbnQuZ2V0RWxlbWVudEJ5SWQoJ291dHB1dCcpCiAgICBmb3IgKGxldCBpID0gMDsgaSA8PSAxMDsgKytpKSB7CiAgICAgIG91dHB1dC52YWx1ZSArPSBgcmFuZG9tKCR7aX0pID0gJHtleHBvcnRzLnJhbmRvbSgpfVxuYAogICAgfQogIH0pCjwvc2NyaXB0Pg==, passed through [\`wat2wasm\`](https://webassembly.github.io/wabt/demo/wat2wasm/), with [some improvements by \`maxgraey\`](https://news.ycombinator.com/item?id=24281261)), and passed through an online [\`wat2wasm\`](https://webassembly.github.io/wabt/demo/wat2wasm/) converter \`\`\`typescript const eps: f64 = 2.3283064365386963e-10; const m: u64 = 6364136223846793005; const inc: u64 = 1442695040888963407; let state: u64 = 1; export function random(): f64 { let oldstate = state * 6364136223846793005 + 1442695040888963407; state = oldstate; const xorshifted = u32(((oldstate >>> 18) ^ oldstate) >> 27); const out_int = rotr(xorshifted, u32(oldstate >> 59)); return eps * out_int; } \`\`\` `30:T626,pcgrandom = { // Note that the index order [0, 1, 2, 3] is little-endian const eps = Math.pow(2, -32), m0 = 0x7F2D, m1 = 0x4C95, m2 = 0xF42D, m3 = 0x5851, // 6364136223846793005 a0 = 0x814F, a1 = 0xF767, a2 = 0x7B7E, a3 = 0x1405, // 1442695040888963407 state = Uint16Array.from({length: 4}, () => Math.random() * 0x10000); // random seed return function pcgrandom() { // Advance internal state const s0 = state[0], s1 = state[1], s2 = state[2], s3 = state[3], // t = m * state t0 = m0*s0, t1 = m0*s1 + m1*s0, t2 = m0*s2 + m1*s1 + m2*s0, t3 = m0*s3 + m1*s2 + m2*s1 + m3*s0, // state = a + t a0pt0 = a0 + t0, a1pt1 = a1 + t1 + (a0pt0 >>> 16), a2pt2 = a2 + t2 + (a1pt1 >>> 16), a3pt3 = a3 + t3 + (a2pt2 >>> 16); state[0] = a0pt0, state[1] = a1pt1, state[2] = a2pt2; state[3] = a3pt3; // Calculate output function (XSH RR) const xorshifted = ( (s3 << 21) + (((s3 >> 2) ^ s2) << 5) + (((s2 >> 2) ^ s1) >> 11)), rot = s3 >> 11, out_int32 = (xorshifted >>> rot) | (xorshifted << ((-rot) & 31)); return eps * (out_int32 >>> 0); } } // In the code above both t2 and t3 can overflow 32 bits, and the // resulting carry bits are lost, but we don’t need to care because // those bits are larger than our 64-bit number anyway. // // a1 + t1 + carry cannot overflow 32 bits because m0 and m1 are too small: // a1 + m0*state[1] + m1*state[0] + carry // <= (2 + 0x7F2D + 0x4C95) * 0xFFFF == 0xCBC3343C31:T54d,pcgrandom_job = { // Note that the index order [0, 1, 2, 3] is little-endian const eps = Math.pow(2, -32), lo = 0xFFFF, m0 = 0x7F2D, m1 = 0x4C95, m2 = 0xF42D, m3 = 0x5851, // 6364136223846793005 a0 = 0x814F, a1 = 0xF767, a2 = 0x7B7E, a3 = 0x1405, // 1442695040888963407 state = Uint16Array.from({length: 4}, () => Math.random() * 0x10000); // random seed return function pcgrandom(){ // Advance internal state const s0 = state[0], s1 = state[1], s2 = state[2], s3 = state[3], new0 = a0 + (s0*m0 & lo), new1 = (a1 + (new0 >>> 16)) + ((s0*m1 & lo) + (s0*m0 >>> 16)) + (s1*m0 & lo), new2 = (a2 + (new1 >>> 16)) + ((s0*m2 & lo) + (s0*m1 >>> 16)) + ((s1*m1 & lo) + (s1*m0 >>> 16)) + (s2*m0 & lo), new3 = (a3 + (new2 >>> 16)) + ((s0*m3 & lo) + (s0*m2 >>> 16)) + ((s1*m2 & lo) + (s1*m1 >>> 16)) + ((s2*m1 & lo) + (s2*m0 >>> 16)) + (s3*m0 & lo); state[0] = new0; state[1] = new1; state[2] = new2; state[3] = new3; // Calculate output function (XSH RR) const xorshifted = ( (s3 << 21) + (((s3 >> 2) ^ s2) << 5) + (((s2 >> 2) ^ s1) >> 11)), rot = s3 >> 11, out_int32 = (xorshifted >>> rot) | (xorshifted << ((-rot) & 31)); return eps * (out_int32 >>> 0); } }32:[{"id":"57b5cc38309b237256ff637cccf7f9ea4b9315bc65b656831ee750e99cf28d4dbf875da1abeb86caeeeeeef69ea032333301f9d01f4babeb430e5c63fe15dd38","href":"https://static.observableusercontent.com/files/57b5cc38309b237256ff637cccf7f9ea4b9315bc65b656831ee750e99cf28d4dbf875da1abeb86caeeeeeef69ea032333301f9d01f4babeb430e5c63fe15dd38","name":"pcgRandom2.wasm","type":"application/wasm","lastModified":1598130593719.103,"size":180},{"id":"37359b6ae3406b04ab9304ffae7d9d2deb5c66efa63ded5b557db60968e5e8596e089dc8285e18f24a1b5475e1d76b3c05a7501d092b0f7603edefa2d9947e03","href":"https://static.observableusercontent.com/files/37359b6ae3406b04ab9304ffae7d9d2deb5c66efa63ded5b557db60968e5e8596e089dc8285e18f24a1b5475e1d76b3c05a7501d092b0f7603edefa2d9947e03","name":"pcg-random-4.wasm","type":"application/wasm","lastModified":1598444350146.079,"size":139}] 2d:{"title":"Permuted congruential generator - WASM","cells":[{"id":0,"value":"md`# Permuted congruential generator - WASM\n\nAnother spin on [Jacob Rus' version of my notebook](https://observablehq.com/@jrus/permuted-congruential-generator): how does WASM compare? ~~On my laptop it's... slower?~~ It *was* slower in 2020, but now (2023) it is consistently faster than JavaScript both on Chromium and Firefox.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":220,"value":"md`\nOriginal C code from the [PCG-random website](https://www.pcg-random.org/):\n\n\\`\\`\\`c\n// *Really* minimal PCG32 code / (c) 2014 M.E. O'Neill / pcg-random.org\n// Licensed under Apache License 2.0 (NO WARRANTY, etc. see website)\n\ntypedef struct { uint64_t state; uint64_t inc; } pcg32_random_t;\n\nuint32_t pcg32_random_r(pcg32_random_t* rng)\n{\n uint64_t oldstate = rng->state;\n // Advance internal state\n rng->state = oldstate * 6364136223846793005ULL + (rng->inc|1);\n // Calculate output function (XSH RR), uses old state for max ILP\n uint32_t xorshifted = ((oldstate >> 18u) ^ oldstate) >> 27u;\n uint32_t rot = oldstate >> 59u;\n return (xorshifted >> rot) | (xorshifted << ((-rot) & 31));\n}\n\\`\\`\\`\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":451,"value":"$2f","pinned":false,"hidden":false,"mode":"ojs"},{"id":538,"value":"wasmModule = await FileAttachment(\"pcg-random-4.wasm\").arrayBuffer()","pinned":true,"hidden":false,"mode":"ojs"},{"id":454,"value":"pcgrandom_wasm = {\nconst wasmInstance =\n await WebAssembly.instantiate(wasmModule, {});\n return wasmInstance.instance.exports.random;\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":614,"value":"Array.from({ length: 1000 }, pcgrandom_wasm)","pinned":true,"hidden":false,"mode":"ojs"},{"id":513,"value":"{\n const n = 1e7;\n const A = new Array(n);\n \n let time = +new Date;\n for (let i = 0; i < n; i++) A[i] = pcgrandom_wasm();\n time = (+new Date - time) / 1000;\n \n return md`${(n / 1e6 / time).toFixed(1)} million pseudorandom numbers per second`\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":606,"value":"md`## Jacob Rus' cleaned up JS version`","pinned":false,"hidden":false,"mode":"ojs"},{"id":90,"value":"$30","pinned":true,"hidden":false,"mode":"ojs"},{"id":258,"value":"{\n const n = 1e7;\n const A = new Array(n).fill(0);\n \n let time = +new Date;\n for (let i = 0; i < n; i++) A[i] = pcgrandom();\n time = (+new Date - time) / 1000;\n \n return md`${(n / 1e6 / time).toFixed(1)} million pseudorandom numbers per second`\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":616,"value":"md`## Job van der Zwan's (fixed) original port`","pinned":false,"hidden":false,"mode":"ojs"},{"id":300,"value":"$31","pinned":true,"hidden":false,"mode":"ojs"},{"id":304,"value":"{\n const n = 1e7;\n const A = new Array(n).fill(0);\n \n let time = +new Date;\n for (let i = 0; i < n; i++) A[i] = pcgrandom_job();\n time = (+new Date - time) / 1000;\n \n return md`${(n / 1e6 / time).toFixed(1)} million pseudorandom numbers per second`\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":12,"value":"{\n const height = 500,\n context = DOM.context2d(width, height);\n\n do {\n context.fillStyle = \"rgba(255,255,255,0.01)\";\n context.fillRect(0, 0, width, height);\n context.fillStyle = \"#000\";\n for (let i = 0; i < width; i++) {\n context.fillRect(width * pcgrandom_wasm(), height * pcgrandom_wasm(), 1, 1);\n }\n yield context.canvas;\n } while (true);\n}","pinned":true,"hidden":false,"mode":"ojs"}],"files":"$W32","stdlib":"1","titling":"auto"}