@tensorflow/tfjs-core
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Hardware-accelerated JavaScript library for machine intelligence
83 lines • 4.42 kB
JavaScript
"use strict";
/**
* @license
* Copyright 2018 Google LLC. All Rights Reserved.
* 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.
* =============================================================================
*/
Object.defineProperty(exports, "__esModule", { value: true });
var util = require("../../util");
/**
* Produces GLSL code that derives logical coordinates from a flat
* index. The code performs integer division with each stride and decrements
* the index until the index equals the final dimension coordinate.
*/
function getLogicalCoordinatesFromFlatIndex(coords, shape, index) {
if (index === void 0) { index = 'index'; }
var strides = util.computeStrides(shape);
return strides
.map(function (stride, i) {
var line1 = "int " + coords[i] + " = " + index + " / " + stride;
var line2 = i === strides.length - 1 ?
"int " + coords[i + 1] + " = " + index + " - " + coords[i] + " * " + stride :
"index -= " + coords[i] + " * " + stride;
return line1 + "; " + line2 + ";";
})
.join('');
}
exports.getLogicalCoordinatesFromFlatIndex = getLogicalCoordinatesFromFlatIndex;
function buildVec(x) {
if (x.length === 1) {
return "" + x[0];
}
return "vec" + x.length + "(" + x.join(',') + ")";
}
/**
* Produces GLSL code that computes the dot product of the input x and y
* vectors. Handles splitting inputs into increments of vec4s when necessary.
*/
function dotify(x, y) {
if (x.length !== y.length) {
throw new Error("Vectors to be dotted must be of the same length -" +
("got " + x.length + " and " + y.length));
}
var slices = [];
var nearestVec4 = Math.floor(x.length / 4);
var nearestVec4Remainder = x.length % 4;
for (var i = 0; i < nearestVec4; i++) {
var xSlice = x.slice(i * 4, i * 4 + 4);
var ySlice = y.slice(i * 4, i * 4 + 4);
slices.push(buildVec(xSlice) + ", " + buildVec(ySlice));
}
if (nearestVec4Remainder !== 0) {
var xSlice = x.slice(nearestVec4 * 4);
var ySlice = y.slice(nearestVec4 * 4);
if (xSlice.length === 1) {
xSlice = xSlice.map(function (d) { return "float(" + d + ")"; });
ySlice = ySlice.map(function (d) { return "float(" + d + ")"; });
}
slices.push(buildVec(xSlice) + ", " + buildVec(ySlice));
}
return slices.map(function (d, i) { return "dot(" + d + ")"; }).join('+');
}
exports.dotify = dotify;
/**
* Produces GLSL that computes the flat index from 3D coordinates.
*/
function getFlatIndexFrom3D(shape) {
var strides = util.computeStrides(shape).map(function (d) { return d.toString(); });
return "\n int getFlatIndex(ivec3 coords) {\n return coords.x * " + strides[0] + " + coords.y * " + strides[1] + " + coords.z;\n }\n";
}
exports.getFlatIndexFrom3D = getFlatIndexFrom3D;
exports.ENCODE_FLOAT_SNIPPET = "\n const float FLOAT_MAX = 1.70141184e38;\n const float FLOAT_MIN = 1.17549435e-38;\n\n lowp vec4 encode_float(highp float v) {\n if (isnan(v)) {\n return vec4(255, 255, 255, 255);\n }\n\n highp float av = abs(v);\n\n if(av < FLOAT_MIN) {\n return vec4(0.0, 0.0, 0.0, 0.0);\n } else if(v > FLOAT_MAX) {\n return vec4(0.0, 0.0, 128.0, 127.0) / 255.0;\n } else if(v < -FLOAT_MAX) {\n return vec4(0.0, 0.0, 128.0, 255.0) / 255.0;\n }\n\n highp vec4 c = vec4(0,0,0,0);\n\n highp float e = floor(log2(av));\n highp float m = exp2(fract(log2(av))) - 1.0;\n\n c[2] = floor(128.0 * m);\n m -= c[2] / 128.0;\n c[1] = floor(32768.0 * m);\n m -= c[1] / 32768.0;\n c[0] = floor(8388608.0 * m);\n\n highp float ebias = e + 127.0;\n c[3] = floor(ebias / 2.0);\n ebias -= c[3] * 2.0;\n c[2] += floor(ebias) * 128.0;\n\n c[3] += 128.0 * step(0.0, -v);\n\n return c / 255.0;\n }\n";
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