Pass in random data to initialize nonce.

diff --git a/src/lib/workers/powgpu.ts b/src/lib/workers/powgpu.ts
index c91df86ace2f2002e24738c7dea87f11dd6ab562..fd04dbe82db916fe41ccd3869b01d92665af68d9 100644 (file)
--- a/src/lib/workers/powgpu.ts
+++ b/src/lib/workers/powgpu.ts
@@ -44,6 +44,7 @@ export class PowGpu extends WorkerInterface {
        static #shader = `
                struct UBO {
                        blockhash: array<vec4<u32>, 2>,
+                       random: u32,
                        threshold: u32
                };
                @group(0) @binding(0) var<uniform> ubo: UBO;
@@ -138,10 +139,8 @@ export class PowGpu extends WorkerInterface {
 
                /**
                * Main compute function
-               *
-               * 8-byte work is split into two 4-byte u32
-               * First 4 bytes will be iterated by shader
-               * Last 4 bytes are defined by index of each thread
+               * 8-byte work is split into two 4-byte u32. Low 4 bytes are random u32 from
+               * UBO. High 4 bytes are the random value XOR'd with index of each thread.
                */
                @compute @workgroup_size(256)
                fn main(
@@ -156,8 +155,8 @@ export class PowGpu extends WorkerInterface {
                                                                                ((workgroup_id.z & 0xff) << 8) |
                                                                                (local_id.x & 0xff);
                        var m: array<u32, 16>;
-                       m[0u] = id;
-                       m[1u] = reverseBits(id);
+                       m[0u] = ubo.random;
+                       m[1u] = id ^ ubo.random;
                        m[2u] = ubo.blockhash[0u].x;
                        m[3u] = ubo.blockhash[0u].y;
                        m[4u] = ubo.blockhash[0u].z;
@@ -190,30 +189,27 @@ export class PowGpu extends WorkerInterface {
                        );
 
                        /**
-                       * Iterate and hash until nonce found
+                       * Twelve rounds of mixing as part of compression step
                        */
-                       for (var j: u32 = 0u; j < 0x1u; j = j + 1u) {
-                               m[0u] = m[0u] ^ j;
-
-                               // twelve rounds of mixing
-                               for (var i: u32 = 0u; i < 12u; i = i + 1u) {
-                                       G(&v, &m, 0u, 8u, 16u, 24u, SIGMA82[i * 16u + 0u], SIGMA82[i * 16u + 1u]);
-                                       G(&v, &m, 2u, 10u, 18u, 26u, SIGMA82[i * 16u + 2u], SIGMA82[i * 16u + 3u]);
-                                       G(&v, &m, 4u, 12u, 20u, 28u, SIGMA82[i * 16u + 4u], SIGMA82[i * 16u + 5u]);
-                                       G(&v, &m, 6u, 14u, 22u, 30u, SIGMA82[i * 16u + 6u], SIGMA82[i * 16u + 7u]);
-                                       G(&v, &m, 0u, 10u, 20u, 30u, SIGMA82[i * 16u + 8u], SIGMA82[i * 16u + 9u]);
-                                       G(&v, &m, 2u, 12u, 22u, 24u, SIGMA82[i * 16u + 10u], SIGMA82[i * 16u + 11u]);
-                                       G(&v, &m, 4u, 14u, 16u, 26u, SIGMA82[i * 16u + 12u], SIGMA82[i * 16u + 13u]);
-                                       G(&v, &m, 6u, 8u, 18u, 28u, SIGMA82[i * 16u + 14u], SIGMA82[i * 16u + 15u]);
-                               }
+                       for (var i: u32 = 0u; i < 12u; i = i + 1u) {
+                               G(&v, &m, 0u, 8u, 16u, 24u, SIGMA82[i * 16u + 0u], SIGMA82[i * 16u + 1u]);
+                               G(&v, &m, 2u, 10u, 18u, 26u, SIGMA82[i * 16u + 2u], SIGMA82[i * 16u + 3u]);
+                               G(&v, &m, 4u, 12u, 20u, 28u, SIGMA82[i * 16u + 4u], SIGMA82[i * 16u + 5u]);
+                               G(&v, &m, 6u, 14u, 22u, 30u, SIGMA82[i * 16u + 6u], SIGMA82[i * 16u + 7u]);
+                               G(&v, &m, 0u, 10u, 20u, 30u, SIGMA82[i * 16u + 8u], SIGMA82[i * 16u + 9u]);
+                               G(&v, &m, 2u, 12u, 22u, 24u, SIGMA82[i * 16u + 10u], SIGMA82[i * 16u + 11u]);
+                               G(&v, &m, 4u, 14u, 16u, 26u, SIGMA82[i * 16u + 12u], SIGMA82[i * 16u + 13u]);
+                               G(&v, &m, 6u, 8u, 18u, 28u, SIGMA82[i * 16u + 14u], SIGMA82[i * 16u + 15u]);
+                       }
 
-                               // Store the result directly into work array
-                               if (atomicLoad(&work.found) == 0u && (BLAKE2B_IV32_1 ^ v[1u] ^ v[17u]) > ubo.threshold) {
-                                       atomicStore(&work.found, 1u);
-                                       work.nonce.x = m[0];
-                                       work.nonce.y = m[1];
-                                       return;
-                               }
+                       /**
+                       * Set nonce if it passes the threshold and no other thread has set it
+                       */
+                       if (atomicLoad(&work.found) == 0u && (BLAKE2B_IV32_1 ^ v[1u] ^ v[17u]) > ubo.threshold) {
+                               atomicStore(&work.found, 1u);
+                               work.nonce.x = m[0];
+                               work.nonce.y = m[1];
+                               return;
                        }
 
                        return;
@@ -300,12 +296,15 @@ export class PowGpu extends WorkerInterface {
                }
 
                // Set up uniform buffer object
-               const uboView = new DataView(new ArrayBuffer(48))
+               const uboView = new DataView(new ArrayBuffer(64))
                for (let i = 0; i < 64; i += 8) {
                        const uint32 = hashHex.slice(i, i + 8)
                        uboView.setUint32(i / 2, parseInt(uint32, 16))
                }
-               uboView.setUint32(32, threshold, true)
+               const random = crypto.getRandomValues(new Uint32Array(1))[0]
+               console.log(`random: ${random}`)
+               uboView.setUint32(32, random, true)
+               uboView.setUint32(48, threshold, true)
                const uboBuffer = PowGpu.#device.createBuffer({
                        size: uboView.byteLength,
                        usage: GPUBufferUsage.UNIFORM | GPUBufferUsage.COPY_DST,