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+<!--
+Copyright (c) 2019 The Khronos Group Inc.
+Use of this source code is governed by an MIT-style license that can be
+found in the LICENSE.txt file.
+-->
+
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+<title>Bug - the precision qualifier of a constant variable should affect the precision of a consuming operation</title>
+<link rel="stylesheet" href="../../../resources/js-test-style.css"/>
+<script src="../../../js/js-test-pre.js"></script>
+<script src="../../../js/webgl-test-utils.js"></script>
+<script src="../../../js/glsl-conformance-test.js"></script>
+</head>
+<body>
+<div id="description"></div>
+<div id="console"></div>
+<script id="fshader" type="x-shader/x-fragment">
+// It is assumed that uTest is set to 0. It's here to make the expression not constant.
+uniform mediump float uTest;
+
+void main() {
+    // exact representation of 4096.5 requires 13 bits of relative precision.
+    const highp float c = 4096.5;
+    mediump float a = 0.0;
+    // Below, addition should be evaluated at highp, since one of the operands has the highp qualifier.
+    // Thus fract should also be evaluated at highp.
+    // See OpenGL ES Shading Language spec section 4.5.2.
+    // This should make the result 0.5, since highp provides at least 16 bits of relative precision.
+    // (exceptions for operation precision are allowed for a small number of computationally
+    // intensive built-in functions, but it is reasonable to think that fract is not one of those).
+    // However, if fract() is incorrectly evaluated at minimum precision fulfilling mediump criteria,
+    // or at IEEE half float precision, the result is 0.0.
+    a = fract(c + uTest);
+
+    // Multiply by 2.0 to make the color green.
+    gl_FragColor = vec4(0.0, 2.0 * a, 0.0, 1.0);
+}
+</script>
+<script id="fshaderNoConstants" type="x-shader/x-fragment">
+// This shader has the same functionality as the one above, but it doesn't contain
+// operations that can be constant folded at compile-time.
+// It's here to provide a point of comparison.
+uniform mediump float uTest;
+uniform highp float uTestHigh;
+
+void main() {
+    highp float c = 4096.5 + uTestHigh;
+    mediump float a = 0.0;
+    a = fract(c + uTest);
+    gl_FragColor = vec4(0.0, 2.0 * a, 0.0, 1.0);
+}
+</script>
+<script id="fshaderAllHighp" type="x-shader/x-fragment">
+// This shader has the same functionality as the one above, but it only uses highp.
+// It's here to provide a point of comparison.
+uniform highp float uTest;
+
+void main() {
+    highp float c = 4096.5 + uTest;
+    highp float a = 0.0;
+    a = fract(c + uTest);
+    gl_FragColor = vec4(0.0, 2.0 * a, 0.0, 1.0);
+}
+</script>
+<script type="application/javascript">
+"use strict";
+description();
+
+function test() {
+  var wtu = WebGLTestUtils;
+  var gl = wtu.create3DContext();
+  if (!gl) {
+    testFailed("context does not exist");
+    finishTest();
+    return;
+  }
+  if (gl.getShaderPrecisionFormat(gl.FRAGMENT_SHADER, gl.HIGH_FLOAT).precision == 0) {
+    testPassed("highp precision not supported");
+    finishTest();
+  } else {
+    GLSLConformanceTester.runRenderTests([
+    {
+      fShaderId: 'fshader',
+      fShaderSuccess: true,
+      linkSuccess: true,
+      passMsg: 'The precision qualifier of a constant affects built-in function results',
+      uniforms: [{name: "uTest", functionName: "uniform1f", value: 0}]
+    },
+    {
+      fShaderId: 'fshaderNoConstants',
+      fShaderSuccess: true,
+      linkSuccess: true,
+      passMsg: 'The precision qualifier of a variable affects built-in function results',
+      uniforms: [{name: "uTest", functionName: "uniform1f", value: 0},
+                 {name: "uTestHigh", functionName: "uniform1f", value: 0}]
+    },
+    {
+      fShaderId: 'fshaderAllHighp',
+      fShaderSuccess: true,
+      linkSuccess: true,
+      passMsg: 'All variables are qualified as highp',
+      uniforms: [{name: "uTest", functionName: "uniform1f", value: 0}]
+    },
+    ]);
+  }
+};
+
+test();
+var successfullyParsed = true;
+</script>
+</body>
+</html>