1 files changed, 91 insertions, 0 deletions
diff --git a/dom/webgpu/tests/cts/checkout/src/webgpu/shader/values.ts b/dom/webgpu/tests/cts/checkout/src/webgpu/shader/values.ts
new file mode 100644
index 0000000000..38a2fe46f0
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+++ b/dom/webgpu/tests/cts/checkout/src/webgpu/shader/values.ts
@@ -0,0 +1,91 @@
+export const description = `Special and sample values for WGSL scalar types`;
+
+import { assert } from '../../common/util/util.js';
+import { uint32ToFloat32 } from '../util/conversion.js';
+
+/** Returns an array of subnormal f32 numbers.
+ * Subnormals are non-zero finite numbers with the minimum representable
+ * exponent.
+ */
+export function subnormalF32Examples(): Array<number> {
+  // The results, as uint32 values.
+  const result_as_bits: number[] = [];
+
+  const max_mantissa = 0x7f_ffff;
+  const sign_bits = [0, 0x8000_0000];
+  for (const sign_bit of sign_bits) {
+    // exponent bits must be zero.
+    const sign_and_exponent = sign_bit;
+
+    // Set all bits
+    result_as_bits.push(sign_and_exponent | max_mantissa);
+
+    // Set each of the lower bits individually.
+    for (let lower_bits = 1; lower_bits <= max_mantissa; lower_bits <<= 1) {
+      result_as_bits.push(sign_and_exponent | lower_bits);
+    }
+  }
+  assert(
+    result_as_bits.length === 2 * (1 + 23),
+    'subnormal number sample count is ' + result_as_bits.length.toString()
+  );
+  return result_as_bits.map(u => uint32ToFloat32(u));
+}
+
+/** Returns an array of normal f32 numbers.
+ * Normal numbers are not: zero, Nan, infinity, subnormal.
+ */
+export function normalF32Examples(): Array<number> {
+  const result: number[] = [1.0, -2.0];
+
+  const max_mantissa_as_bits = 0x7f_ffff;
+  const min_exponent_as_bits = 0x0080_0000;
+  const max_exponent_as_bits = 0x7f00_0000; // Max normal exponent
+  const sign_bits = [0, 0x8000_0000];
+  for (const sign_bit of sign_bits) {
+    for (let e = min_exponent_as_bits; e <= max_exponent_as_bits; e += min_exponent_as_bits) {
+      const sign_and_exponent = sign_bit | e;
+
+      // Set zero mantissa bits
+      result.push(uint32ToFloat32(sign_and_exponent));
+      // Set all mantissa bits
+      result.push(uint32ToFloat32(sign_and_exponent | max_mantissa_as_bits));
+
+      // Set each of the lower bits individually.
+      for (let lower_bits = 1; lower_bits <= max_mantissa_as_bits; lower_bits <<= 1) {
+        result.push(uint32ToFloat32(sign_and_exponent | lower_bits));
+      }
+    }
+  }
+  assert(
+    result.length === 2 + 2 * 254 * 25,
+    'normal number sample count is ' + result.length.toString()
+  );
+  return result;
+}
+
+/** Returns an array of 32-bit NaNs, as Uint32 bit patterns.
+ * NaNs have: maximum exponent, but the mantissa is not zero.
+ */
+export function nanF32BitsExamples(): Array<number> {
+  const result: number[] = [];
+  const exponent_bit = 0x7f80_0000;
+  const sign_bits = [0, 0x8000_0000];
+  for (const sign_bit of sign_bits) {
+    const sign_and_exponent = sign_bit | exponent_bit;
+    const bits = sign_and_exponent | 0x40_0000;
+    // Only the most significant bit of the mantissa is set.
+    result.push(bits);
+
+    // Quiet and signalling NaNs differ based on the most significant bit
+    // of the mantissa. Try both.
+    for (const quiet_signalling of [0, 0x40_0000]) {
+      // Set each of the lower bits.
+      for (let lower_bits = 1; lower_bits < 0x40_0000; lower_bits <<= 1) {
+        const bits = sign_and_exponent | quiet_signalling | lower_bits;
+        result.push(bits);
+      }
+    }
+  }
+  return result;
+}