SPIRV-Tools/tools/sva/src/assembler.js
dan sinclair 605c2e3c0e
Add WebGPU SPIR-V Assembler in JavaScript. (#2876)
This CL adds a simple JavaScript library which will assemble SPIR-V
Assembly compatable with WebGPU.
2019-09-18 18:11:10 -04:00

99 lines
2.5 KiB
JavaScript

// Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
export default class Assembler {
static get GENERATOR_ID() { return 0; }
/**
* @param {AST} the AST to build the SPIR-V from
*/
constructor(ast) {
this.ast_ = ast;
}
/**
* Assembles the AST into binary SPIR-V.
* @return {Uint32Array} The SPIR-V binary data.
*/
assemble() {
let total_size = 5;
for (const inst of this.ast_.instructions()) {
total_size += 1;
for (const op of inst.operands()) {
total_size += op.length();
}
}
let u = new Uint32Array(total_size);
u[0] = 0x07230203; // Magic
u[1] = 0x00010500; // Version 1.5
u[2] = Assembler.GENERATOR_ID; // Generator magic number
u[3] = this.ast_.getIdBounds(); // ID bounds
u[4] = 0; // Reserved
let idx = 5;
for (const inst of this.ast_.instructions()) {
let op_size = 1;
for (const op of inst.operands()) {
op_size += op.length();
}
u[idx++] = op_size << 16 | inst.opcode();
for (const op of inst.operands()) {
idx = this.processOp(u, idx, op);
}
}
return u;
}
processOp(u, idx, op) {
if (op.type() === "string") {
let len = 0;
let v = 0;
for (const ch of op.value()) {
v = v | (ch.charCodeAt(0) << (len * 8));
len += 1;
if (len === 4) {
u[idx++] = v;
len = 0;
v = 0;
}
}
// Make sure either the terminating 0 byte is written or the last
// partial word is written.
u[idx++] = v;
} else if (op.type() === "float") {
// TODO(dsinclair): Handle 64 bit floats ...
let b = new ArrayBuffer(4);
let f = new Float32Array(b);
f[0] = op.value();
let u2 = new Uint32Array(b);
u[idx++] = u2[0];
} else {
u[idx++] = op.value();
}
for (const param of op.params()) {
idx = this.processOp(u, idx, param);
}
return idx;
}
}